scholarly journals Brain-Specific Serine-47 Modification of Cytochrome c Regulates Cytochrome c Oxidase Activity Attenuating ROS Production and Cell Death: Implications for Ischemia/Reperfusion Injury and Akt Signaling

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1843 ◽  
Author(s):  
Hasini A. Kalpage ◽  
Junmei Wan ◽  
Paul T. Morse ◽  
Icksoo Lee ◽  
Maik Hüttemann
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Reperfusion Injury ◽  
Cell Line ◽  
Cytochrome C Oxidase ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Ros Generation ◽  
Ros Production ◽  
The Brain

We previously reported that serine-47 (S47) phosphorylation of cytochrome c (Cytc) in the brain results in lower cytochrome c oxidase (COX) activity and caspase-3 activity in vitro. We here analyze the effect of S47 modification in fibroblast cell lines stably expressing S47E phosphomimetic Cytc, unphosphorylated WT, or S47A Cytc. Our results show that S47E Cytc results in partial inhibition of mitochondrial respiration corresponding with lower mitochondrial membrane potentials (ΔΨm) and reduced reactive oxygen species (ROS) production. When exposed to an oxygen-glucose deprivation/reoxygenation (OGD/R) model simulating ischemia/reperfusion injury, the Cytc S47E phosphomimetic cell line showed minimal ROS generation compared to the unphosphorylated WT Cytc cell line that generated high levels of ROS upon reoxygenation. Consequently, the S47E Cytc cell line also resulted in significantly lower cell death upon exposure to OGD/R, confirming the cytoprotective role of S47 phosphorylation of Cytc. S47E Cytc also resulted in lower cell death upon H2O2 treatment. Finally, we propose that pro-survival kinase Akt (protein kinase B) is a likely mediator of the S47 phosphorylation of Cytc in the brain. Akt inhibitor wortmannin abolished S47 phosphorylation of Cytc, while the Akt activator SC79 maintained S47 phosphorylation of Cytc. Overall, our results suggest that loss of S47 phosphorylation of Cytc during brain ischemia drives reperfusion injury through maximal electron transport chain flux, ΔΨm hyperpolarization, and ROS-triggered cell death.

scholarly journals Enhancing Glycolysis Protects against Ischemia-Reperfusion Injury by Reducing ROS Production

Metabolites ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 132
Author(s):  
Claudia Beltran ◽  
Rosario Pardo ◽  
Diana Bou-Teen ◽  
Marisol Ruiz-Meana ◽  
Josep A. Villena ◽  
...  
Keyword(s):  
Cell Death ◽  
Myocardial Ischemia ◽  
Reperfusion Injury ◽  
Glucose Oxidation ◽  
Ischemia Reperfusion Injury ◽  
Aerobic Glycolysis ◽  
Ischemia Reperfusion ◽  
Ros Production ◽  
Metabolic Shift ◽  
Myocardial Ischemia Reperfusion

After myocardial ischemia-reperfusion, fatty acid oxidation shows fast recovery while glucose oxidation rates remain depressed. A metabolic shift aimed at increasing glucose oxidation has shown to be beneficial in models of myocardial ischemia-reperfusion. However, strategies aimed at increasing glucose consumption in the clinic have provided mixed results and have not yet reached routine clinical practice. A better understanding of the mechanisms underlying the protection afforded by increased glucose oxidation may facilitate the transfer to the clinic. The purpose of this study was to evaluate if the modulation of reactive oxygen species (ROS) was involved in the protection afforded by increased glucose oxidation. Firstly, we characterized an H9C2 cellular model in which the use of glucose or galactose as substrates can modulate glycolysis and oxidative phosphorylation pathways. In this model, there were no differences in morphology, cell number, or ATP and PCr levels. However, galactose-grown cells consumed more oxygen and had an increased Krebs cycle turnover, while cells grown in glucose had increased aerobic glycolysis rate as demonstrated by higher lactate and alanine production. Increased aerobic glycolysis was associated with reduced ROS levels and protected the cells against simulated ischemia-reperfusion injury. Furthermore, ROS scavenger N-acetyl cysteine (NAC) was able to reduce the amount of ROS and to prevent cell death. Lastly, cells grown in galactose showed higher activation of mTOR/Akt signaling pathways. In conclusion, our results provide evidence indicating that metabolic shift towards increased glycolysis reduces mitochondrial ROS production and prevents cell death during ischemia-reperfusion injury.

scholarly journals Inhibiting Cytochrome C Oxidase Leads to Alleviated Ischemia Reperfusion Injury

2017 ◽  
Vol 47 (2) ◽  
pp. 193 ◽  
Author(s):  
Zhaoyun Yang ◽  
Zhongxin Duan ◽  
Tian Yu ◽  
Junmei Xu ◽  
Lei Liu
Keyword(s):  
Cytochrome C ◽  
Reperfusion Injury ◽  
Cytochrome C Oxidase ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion

scholarly journals miR-380-5p facilitates NRF2 and attenuates cerebral ischemia/reperfusion injury-induced neuronal cell death by directly targeting BACH1

2021 ◽  
Vol 12 (1) ◽  
pp. 210-217
Author(s):  
Yibiao Wang ◽  
Min Xu
Keyword(s):  
Cell Death ◽  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Luciferase Assay ◽  
Neuroprotective Effects ◽  
Cerebral Ischemia Reperfusion

Abstract Background This study aimed to explore the role of miR-380-5p in cerebral ischemia/reperfusion (CIR) injury-induced neuronal cell death and the potential signaling pathway involved. Methodology Human neuroblastoma cell line SH-SY5Y cells were used in this study. Oxygen and glucose deprivation/reperfusion (OGD/R) model was used to mimic ischemia/reperfusion injury. CCK-8 assay and flow cytometry were used to examine cell survival. Quantitative real time PCR (RT-qPCR) assay and Western blotting were used to measure the change of RNA and protein expression, respectively. TargetScan and Luciferase assay was used to confirm the target of miR-380-5p. Malondialdehyde (MDA) superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) were measured using commercial kits. Results miR-380-5p was downregulated in SH-SY5Y cells after OGD/R. Cell viability was increased by miR-380-5p, while cell apoptosis was reduced by miR-380-5p mimics. MDA was reduced by miR-380-5p mimics, while SOD and GSHPx were increased by miR-380-5p. Results of TargetScan and luciferase assay have showed that BACH1 is the direct target of miR-380-5p. Expression of NRF2 was upregulated after OGD/R, but was not affected by miR-380-5p. mRNA expression of HO-1 and NQO1 and ARE activity were increased by miR-380-5p. Overexpression of BACH1 reversed the antioxidant and neuroprotective effects of miR-380-5p. Conclusion miR-380-5p inhibited cell death induced by CIR injury through target BACH1 which also facilitated the activation of NRF2, indicating the antioxidant and neuroprotective effects of miR-380-5p.

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