scholarly journals Ambra1 Alleviates Hypoxia/Reoxygenation Injury in H9C2 Cells by Regulating Autophagy and Reactive Oxygen Species

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Lin Zhao ◽  
Liting Cheng ◽  
Yongquan Wu
Keyword(s):  
Reactive Oxygen Species ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Reperfusion Therapy ◽  
Oxygen Species ◽  
H9c2 Cells ◽  
Reoxygenation Injury ◽  
Myocardial Ischemia Reperfusion

Reperfusion therapy is the most important method for treating acute myocardial infarction. However, myocardial ischemia reperfusion injury (MIRI) can offset the benefit of reperfusion therapy and worsen the outcome. In both ischemia and reperfusion, autophagy remains problematic. Activating molecule in Beclin1-regulated autophagy (Ambra1) is an important protein in autophagy regulation, and its function in MIRI remains unclear. Thus, we used H9C2 cells to investigate the function of Ambra1 in MIRI and the underlying mechanisms involved. Hypoxia and reoxygenation of H9C2 cells were used to mimic MIRI in vitro. During hypoxia, autophagy flux was blocked, then recovered in reoxygenation. Ambra1 overexpression increased autophagy in the H9C2 cells, as the LC3B II/I ratio increased, and alleviated cellular necrosis and apoptosis during hypoxia and reoxygenation. This effect was counteracted by an autophagy inhibitor. Knocking down Ambra1 can block autophagy which P62 sediment/supernatant ratio increased while the ratio of LC3B II/I decreased, and worsen outcomes. Ambra1 enhances autophagy in H9C2 cells by improving the stability and activity of the ULK1 complex. Reactive oxygen species (ROS) are an important cause of MIRI. ROS were reduced when Ambra1 was overexpressed and increased when Ambra1 was knocked down, indicating that Ambra1 can protect against hypoxia and reoxygenation injury in H9C2 cells by promoting autophagy and reducing ROS.

scholarly journals PER2 Regulates Reactive Oxygen Species Production in the Circadian Susceptibility to Ischemia/Reperfusion Injury in the Heart

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yaqian Weng ◽  
Hui Li ◽  
Lin Gao ◽  
Wenjing Guo ◽  
Shiyuan Xu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
H9c2 Cells ◽  
Oxidative Balance ◽  
Severity Of Injury

The main objective of this study was to investigate the diurnal differences in Period 2 (PER2) expression in myocardial ischemia-reperfusion (I/R) injury. We investigated diurnal variations in oxidative stress and energy metabolism after myocardial I/R in vitro and in vivo. In addition, we also analyzed the effects of H2O2 treatment and serum shock in H9c2 cells transfected with silencing RNA against Per2 (siRNA-Per2) in vitro. We used C57BL/6 male mice to construct a model of I/R injury at zeitgeber time (ZT) 2 and ZT14 by synchronizing the circadian rhythms. Our in vivo analysis demonstrated that there were diurnal differences in the severity of injury caused by myocardial infarctions, with more injury occurring in the daytime. PER2 was significantly reduced in heart tissue in the daytime and was higher at night. Our results also showed that more severe injury of mitochondrial function in daytime produced more reactive oxygen species (ROS) and less ATP, which increased myocardial injury. In vitro, our findings presented a similar trend showing that apoptosis of H9c2 cells was increased when PER2 expression was lower. Meanwhile, downregulation of PER2 disrupted the oxidative balance by increasing ROS and mitochondrial injury. The result was a reduction in ATP and failure to provide sufficient energy protection for cardiomyocytes.

scholarly journals Molecular Characterization of Reactive Oxygen Species in Myocardial Ischemia-Reperfusion Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tingyang Zhou ◽  
Chia-Chen Chuang ◽  
Li Zuo
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Ischemia ◽  
Energy Demand ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
High Energy ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Myocardial Ischemia Reperfusion

Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body’s antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury.

scholarly journals Salvianolic Acid A Protects Against Oxidative Stress and Apoptosis Induced by Intestinal Ischemia-Reperfusion Injury Through Activation of Nrf2/HO-1 Pathways

2018 ◽  
Vol 49 (6) ◽  
pp. 2320-2332 ◽  
Author(s):  
Guo Zu ◽  
Tingting Zhou ◽  
Ningwei Che ◽  
Xiangwen Zhang
Keyword(s):  
Reactive Oxygen Species ◽  
Glutathione Peroxidase ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Salvianolic Acid ◽  
Salvianolic Acid A ◽  
Tnf Α

Background/Aims: Ischemia-reperfusion (I/R) adversely affects the intestinal mucosa. The major mechanisms of I/R are the generation of reactive oxygen species (ROS) and apoptosis. Salvianolic acid A (SalA) is suggested to be an effective antioxidative and antiapoptotic agent in numerous pathological injuries. The present study investigated the protective role of SalA in I/R of the intestine. Methods: Adult male Sprague-Dawley rats were subjected to intestinal I/R injury in vivo. In vitro experiments were performed in IEC-6 cells subjected to hypoxia/ reoxygenation (H/R) stimulation to simulate intestinal I/R. TNF-α, IL-1β, and IL-6 levels were measured using enzyme-linked immunosorbent assay. Malondialdehyde and myeloperoxidase and glutathione peroxidase levels were measured using biochemical analysis. Apoptosis was measured by terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling staining or flow cytometry in vivo and in vitro. The level of reactive oxygen species (ROS) was measured by dichlorodihydrofluorescin diacetate (DCFH-DA) staining. Western blotting was performed to determine the expression of heme oxygenase-1 (HO-1), Nrf2 and proteins associated with apoptosis. The mRNA expressions of Nrf2 and HO-1 were detected by quantitative real-time polymerase chain reaction in vivo and in vitro. Results: Malondialdehyde level and myeloperoxidase and glutathione peroxidase, TNF-α, IL-1β, and IL-6 levels group in intestinal tissue decreased significantly in the SalA pretreatment groups compared to the I/R group. SalA markedly abolished intestinal injury compared to the I/R group. SalA significantly attenuated apoptosis and increased Nrf2/HO-1 expression in vivo and in vitro. However, Nrf2 siRNA treatment partially abrogated the above mentioned effects of SalA in H/R-induced ROS and apoptosis in IEC-6 cells. Conclusion: The present study demonstrated that SalA ameliorated oxidation, inhibited the release of pro-inflammatory cytokines and alleviated apoptosis in I/R-induced injury and that these protective effects may partially occur via regulation of the Nrf2/ HO-1 pathways.

scholarly journals Reactive Oxygen Species (ROS)-Activatable Prodrug for Selective Activation of ATF6 after Ischemia/Reperfusion Injury

2019 ◽  
Vol 11 (3) ◽  
pp. 292-297 ◽  
Author(s):  
Jonathan E. Palmer ◽  
Breanna M. Brietske ◽  
Tyler C. Bate ◽  
Erik A. Blackwood ◽  
Manasa Garg ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Selective Activation

scholarly journals Phospholipid oxidation products in ferroptotic myocardial cell death

2019 ◽  
Vol 317 (1) ◽  
pp. H156-H163 ◽  
Author(s):  
Aleksandra Stamenkovic ◽  
Grant N. Pierce ◽  
Amir Ravandi
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Myocardial Cell ◽  
Oxidation Products ◽  
Oxygen Species ◽  
New Therapeutic Approaches

Cell death is an important component of the pathophysiology of any disease. Myocardial disease is no exception. Understanding how and why cells die, particularly in the heart where cardiomyocyte regeneration is limited at best, becomes a critical area of study. Ferroptosis is a recently described form of nonapoptotic cell death. It is an iron-mediated form of cell death that occurs because of accumulation of lipid peroxidation products. Reactive oxygen species and iron-mediated phospholipid peroxidation is a hallmark of ferroptosis. To date, ferroptosis has been shown to be involved in cell death associated with Alzheimer’s disease, Huntington’s disease, cancer, Parkinson’s disease, and kidney degradation. Myocardial reperfusion injury is characterized by iron deposition as well as reactive oxygen species production. These conditions, therefore, favor the induction of ferroptosis. Currently there is no available treatment for reperfusion injury, which accounts for up to 50% of the final infarct size. This review will summarize the evidence that ferroptosis can induce cardiomyocyte death following reperfusion injury and the potential for this knowledge to open new therapeutic approaches for myocardial ischemia-reperfusion injury.

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