Abstract 355: Effect of Poloxamer 188 on Rat Brain Isolated Mitochondria After Exposure to Hydrogen Peroxide

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Johannes A Pille ◽  
Michele M Salzman ◽  
Anna A Sonju ◽  
Felicia P Lotze ◽  
Josephine E Hees ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Oxygen Consumption ◽  
Mitochondrial Function ◽  
Complex I ◽  
Room Temperature ◽  
In Vitro Model ◽  
Atp Synthesis ◽  
Complex Ii ◽  
Vitro Model

Introduction: In a pig model of myocardial infarction (MI), intracoronary delivered Poloxamer (P) 188 significantly reduces ischemia/reperfusion (IR) injury when given immediately upon reperfusion, with improved mitochondrial function as a predominant effect. As mitochondria are heavily damaged during IR, a direct effect of P188 on mitochondria may lead to better therapy options during reperfusion. To show not only a similar reduction of IR injury by P188 in the brain, but also a direct P188 effect on mitochondria, we established an in-vitro model of IR that consists of damaging isolated rat brain mitochondria with hydrogen peroxide (H 2 O 2 ), one component of ischemia, then applying P188, and analyzing mitochondrial function. Methods: Male Sprague-Dawley rat brains were removed, and the mitochondria isolated by differential centrifugation and Percoll gradients, then kept on ice to slow their bioenergetics prior to any experimental treatments. Mitochondria were exposed to 200 μM H 2 O 2 for 10 min at room temperature with slight agitation; controls received no H 2 O 2 . Samples were then diluted ½ with buffer ± P188 (250 μM after dilution) to simulate reperfusion and treatment, and kept at room temperature for 10 further minutes. ATP synthesis was measured in a luminometer using a luciferase enzymatic assay. Oxygen consumption was measured by closed cell respirometry with an oxygen meter. In both assays, Complex I and Complex II were examined; Complex I substrates glutamate and malate, Complex II substrate succinate plus the Complex I inhibitor rotenone. Statistics: Data are expressed as mean ± SEM. One-Way ANOVA, SNK-Test; Kruskal-Wallis-Test; α=0.05, * vs control. Results: In both Complex I and II, mitochondrial function was significantly impaired by H 2 O 2 , with ATP synthesis affected more at Complex I and oxygen consumption affected more at Complex II. Addition of P188 did not provide any significant improvement in mitochondrial function. Conclusions: Although P188 significantly reduced IR injury when given during reperfusion in a pig model of MI, it does not appear to provide direct protection to mitochondria in this in-vitro model. Whether the exposure to H 2 O 2 causes the appropriate injury for P188 to become effective remains to be elucidated.

Polyphenol-hydrogen peroxide reactions in skin: In vitro model relevant to study ROS reactions at inflammation

2019 ◽  
Vol 1075 ◽  
pp. 91-97 ◽  
Author(s):  
Mahboubeh Eskandari ◽  
Jadwiga Rembiesa ◽  
Lauryna Startaitė ◽  
Anna Holefors ◽  
Audronė Valančiūtė ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
In Vitro Model ◽  
Vitro Model

scholarly journals Estimation of the Genotoxicityof Hydrogen Peroxide and Antioxidant Actionof Halo Acid by the Method of Dna-Cometwith the Use of the Model of Transplantable Cell Cultures

2018 ◽  
pp. 40-43
Author(s):  
Olga Verle ◽  
Oleg Ostrovskiy ◽  
Valerian Verovskiy ◽  
Galina Dudchenko
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
In Vitro Model ◽  
Cell Damage ◽  
Protective Action ◽  
Genetic Material ◽  
Optimal Level ◽  
Pharmacological Agents ◽  
Vitro Model

In the framework of the study, the degree of defragmentation of DNA by the DNA-comet method is evaluated when exposed to the cell culture of hydrogen peroxide (H2O2), and an in vitro model is developed to evaluate the antioxidant activity of new pharmacological agents. The results of working with cell lines show that the percentage of damage to the genetic material of cells of intact samples does not greatly vary from the method of removing the cellular monolayer from the culture plastic. Concerning the effect of H2O2 as an inducer of oxidative stress on DNA cell damage, the optimal level of DNA defragmentation has been modeled for subsequent studies of the protective action of antioxidants.

scholarly journals β-Naphthoflavone and Ethanol Reverse Mitochondrial Dysfunction in A Parkinsonian Model of Neurodegeneration

2020 ◽  
Vol 21 (11) ◽  
pp. 3955
Author(s):  
Jesus Fernandez-Abascal ◽  
Elda Chiaino ◽  
Maria Frosini ◽  
Gavin P. Davey ◽  
Massimo Valoti
Keyword(s):  
Complex I ◽  
In Vitro Model ◽  
Inhibitory Effects ◽  
Cyp Induction ◽  
Cyp Isoforms ◽  
Vitro Model ◽  
Complex I Activity ◽  
Cyp 2D6

The 1-methyl-4-phenylpyridinium (MPP+) is a parkinsonian-inducing toxin that promotes neurodegeneration of dopaminergic cells by directly targeting complex I of mitochondria. Recently, it was reported that some Cytochrome P450 (CYP) isoforms, such as CYP 2D6 or 2E1, may be involved in the development of this neurodegenerative disease. In order to study a possible role for CYP induction in neurorepair, we designed an in vitro model where undifferentiated neuroblastoma SH-SY5Y cells were treated with the CYP inducers β-naphthoflavone (βNF) and ethanol (EtOH) before and during exposure to the parkinsonian neurotoxin, MPP+. The toxic effect of MPP+ in cell viability was rescued with both βNF and EtOH treatments. We also report that this was due to a decrease in reactive oxygen species (ROS) production, restoration of mitochondrial fusion kinetics, and mitochondrial membrane potential. These treatments also protected complex I activity against the inhibitory effects caused by MPP+, suggesting a possible neuroprotective role for CYP inducers. These results bring new insights into the possible role of CYP isoenzymes in xenobiotic clearance and central nervous system homeostasis.

P5994Role of BGP-15 treatment in hypertensive heart failure progression and mitochondrial protection

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
O Horvath ◽  
L Deres ◽  
K Ordog ◽  
K Bruszt ◽  
B Sumegi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mitochondrial Function ◽  
Cardiac Remodeling ◽  
In Vitro Model ◽  
Mitochondrial Dynamics ◽  
Treated Group ◽  
Mitochondrial Structure ◽  
Vitro Model ◽  
And Function

Abstract Introduction The deterioration of mitochondrial quality control greatly contributes to the hypertension induced cardiac remodeling and progression of heart failure. Our previous in vitro results demonstrated the mitochondrial protective effect of antioxidant BGP-15 compound in the presence of cellular stress. Purpose In our recent study we investigated the effect of BGP-15 on cardiac remodeling in spontaneously hypertensive rats (SHR) with manifested heart failure and on mitochondrial dynamics and function in cell culture model. Methods 15-month-old male SHR received 25 mg/kg/day BGP-15 (SHR-B) or placebo (SHR-C) for 18 weeks. Age matched Wistar rats (WKY) were used as normotensive control. The heart function was monitored by echocardiography. Histological preparations were made from cardiac tissue. Neonatal rat cardiomyocytes (NRCMs) were used as in vitro model. 150 μM H2O2 stress and 50 μM BGP-15 treatment was applied. Mitochondrial network was stained with MitoTracker Red. Mitochondrial membrane potential was detected using JC-1 dye, while mitochondrial function was monitored by the Agilent Seahorse XFp, Cell Mito Stress Test. In both model the cellular levels of mitochondrial dynamics proteins were measured in Western blot. To study the ultrastructure we used electron microscopy in our in vivo and in vitro model. Results Left ventricular (LV) mass and LV wall thickness were increased significantly in SHR-C group compared to the initial values (p<0.05). These parameters were decreased considerably in the SHR-B group. Ejection fraction (EF%) decreased in both SHR group although this downturn was minimal because of the treatment. Chronic high blood pressure caused higher collagen deposition in SHR-C rats that was significantly diminished in the SHR-B group. Regarding the mitochondrial function decrease in the levels of fusion proteins OPA1 and MFN2 was observed in the SHR-C group. These differences were significantly reduced by BGP-15 treatment (p<0.05). Mitigation of the level of fission protein DRP1 was however reduced by BGP-15 (p<0.05). In our cellular model, we observed that the H2O2-induced mitochondrial fragmentation was decreased by BGP-15 treatment (p<0.05). BGP-15 treatment prevented mitochondrial membrane potential fall in H2O2 stress (p<0.05). There was no significant difference in basal respiration among groups by monitoring the mitochondrial function. The maximal respiration capacity and ATP production were significantly higher in the BGP-15 treated group in comparison to the stressed group (p<0.05). Conclusion BGP-15 treatment has beneficial effects on mitochondrial dynamics and structure by promoting fusion processes. It also supports the maintenance of mitochondrial function through the preservation of the mitochondrial structure. The mitigation of remodeling processes and the preserved EF in the treated group are results at least partly of the comprehensible effects of BGP-15 on mitochondrial structure and function. Acknowledgement/Funding GINOP-2.3.2-15-2016-00049; GINOP-2.3.2-15-2016-00048; GINOP-2.3.3-15-2016-00025

scholarly journals Evaluation of low-grade In Vitro Oxidative Stress in Goat Erythrocytes ‎Exposed to Hydrogen Peroxide and Dexamethasone ‎

2021 ◽  
Vol 18 (2) ◽  
pp. 33-37
Author(s):  
M. B. Monguno ◽  
E. S. Philip ◽  
I. C. Uku ◽  
I. O. Igbokwe
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
In Vitro Model ◽  
Sucrose Solution ◽  
Osmotic Fragility ◽  
Low Grade ◽  
Mean Values ◽  
Red Blood Cell Count ◽  
Vitro Model

Under conditions of oxidative stress, erythrocytes of goats could be predisposed to haemolysis. This study was aimed at evaluating the effect of oxidant exposure to goat erythrocytes using an in vitro model. Blood samples from 10 goats were incubated with 0.06 – 0.18 mM hydrogen peroxide (H2O2) either singly or in combination with 0.02 µM dexamethasone for 60 min, and erythrocyte parameters such as packed cell volume (PCV), red blood cell count (RBC), mean corpuscular volume (MCV) and percentage haemolysis in hypotonic sucrose solution (250 mOsmol/L) were determined thereafter. No significant changes in the mean values of all parameters were observed. The in vitro model indicated that erythrocyte parameters remained stable under low-grade oxidant exposure in goats. Therefore, plasma H2O2 concentration of ≤ 0.18 mM, whether in the presence or absence of 0.02 µM dexamethasone, may not induce apparent oxidative damage in goat erythrocytes that could be estimated by PCV, RBC, MCV and sucrose-based osmotic fragility at low hypotonicity.

Effect of hyperthermia and acidosis on equine skeletal muscle mitochondrial oxygen consumption

2020 ◽  
pp. 1-10
Author(s):  
M.S. Davis ◽  
M.R. Fulton ◽  
A. Popken
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Muscle Fatigue ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Mitochondrial Oxygen Consumption ◽  
Biochemical Basis ◽  
Complex Ii

The skeletal muscle of exercising horses develops pronounced hyperthermia and acidosis during strenuous or prolonged exercise, with very high tissue temperature and low pH associated with muscle fatigue or damage. The purpose of this study was to evaluate the individual effects of physiologically relevant hyperthermia and acidosis on equine skeletal muscle mitochondrial function, using ex vivo measurement of oxygen consumption to assess the function of different mitochondrial elements. Fresh triceps muscle biopsies from 6 healthy unfit Thoroughbred geldings were permeabilised to permit diffusion of small molecular weight substrates through the sarcolemma and analysed in a high resolution respirometer at 38, 40, 42, and 44 °C, and pH=7.1, 6.5, and 6.1. Oxygen consumption was measured under conditions of non-phosphorylating (leak) respiration and phosphorylating respiration through Complex I and Complex II. Data were analysed using a one-way repeated measures ANOVA and data are expressed as mean ± standard deviation. Leak respiration was ~3-fold higher at 44 °C compared to 38 °C regardless of electron source (Complex I: 22.88±3.05 vs 8.08±1.92 pmol O2/mg/s), P=0.002; Complex II: 79.14±23.72 vs 21.43±11.08 pmol O2/mg/s, P=0.022), resulting in a decrease in efficiency of oxidative phosphorylation. Acidosis had minimal effect on mitochondrial respiration at pH=6.5, but pH=6.1 resulted in a 50% decrease in mitochondrial oxygen consumption. These results suggest that skeletal muscle hyperthermia decreases the efficiency of oxidative phosphorylation through increased leak respiration, thus providing a specific biochemical basis for hyperthermia-induced muscle fatigue. The effect of myocellular acidosis on mitochondrial respiration was minimal under typical levels of acidosis, but atypically severe acidosis can lead to impairment of mitochondrial function.

scholarly journals Neuroprotective effect of hydrogen peroxide on an in vitro model of brain ischaemia

2008 ◽  
Vol 153 (5) ◽  
pp. 1022-1029 ◽  
Author(s):  
R Nisticò ◽  
S Piccirilli ◽  
M L Cucchiaroni ◽  
M Armogida ◽  
E Guatteo ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
In Vitro Model ◽  
Neuroprotective Effect ◽  
Brain Ischaemia ◽  
Vitro Model

Abstract 330: No Direct Mitochondrial Protection Against Ischemia Reperfusion Injury in Rat Isolated Hearts by P188 Postconditioning

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Josephine Eskaf ◽  
Luise J Meyer ◽  
William J Cleveland ◽  
Zhu Li ◽  
Matthias L Riess
Keyword(s):  
Oxygen Consumption ◽  
Mitochondrial Function ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Atp Synthesis ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Retention Capacity

Introduction: Myocardial infarction and cardiac arrest lead to ischemia-reperfusion (IR) injury in the heart. Timely reperfusion through percutaneous coronary intervention and cardiopulmonary resuscitation, respectively, reduces ischemia but also exacerbates myocardial injury. Maintaining mitochondrial function is crucial in maintaining cardiomyocyte function in IR injury. Poloxamer 188 (P188) is a triblock copolymer that has shown protective effects in in-vitro, ex-vivo and in-vivo myocardial IR models. P188 is thought to improve cellular and mitochondrial function during IR by stabilizing membranes. Hypothesis: P188 postconditioning has direct protective effects on mitochondrial function as assessed by ATP synthesis, oxygen consumption and calcium retention capacity (CRC). Methods: After approval by the local authorities, hearts of 42 adult male Sprague-Dawley rats were isolated and perfused ex-vivo with oxygenated Krebs Buffer (KB) for 20 min before 30 min of no-flow ischemia. Hearts were reperfused for 10 min with KB. Cardiac mitochondria were isolated with 1 mM P188 vs 1 mM polyethylene glycol (PEG) vs vehicle by differential centrifugation. Mitochondrial function was assessed for complex I and II substrates of the respiratory chain. Statistics: Kruskal-Wallis with Dunn’s posthoc testing; alpha=0.05. Results: Mitochondrial function decreased significantly after ischemia and showed improvement with reperfusion. P188 did not result in significant improvements in mitochondrial ATP synthesis, oxygen consumption and CRC function after IR, and neither did PEG. Conclusions: P188 does not have a direct protective effect on mitochondria in this model. This might be owed to the fact that no additional damage could be observed after reperfusion which is the type of injury targeted by P188 post-conditioning.

scholarly journals Capsaicin Alleviates the Deteriorative Mitochondrial Function by Upregulating 14-3-3η in Anoxic or Anoxic/Reoxygenated Cardiomyocytes

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Yang Qiao ◽  
Tianhong Hu ◽  
Bin Yang ◽  
Hongwei Li ◽  
Tianpeng Chen ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Complex I ◽  
Redox Homeostasis ◽  
Redox Status ◽  
Neonatal Rat ◽  
Ros Generation ◽  
Consumption Rates ◽  
Vitro Model ◽  
The Impact

Reactive oxygen species (ROS) are byproducts of a defective electron transport chain (ETC). The redox couples, GSH/GSSG and NAD+/NADH, play an essential role in physiology as internal defenses against excessive ROS generation by facilitating intracellular/mitochondrial (mt) redox homeostasis. Anoxia alone and anoxia/reoxygenation (A/R) are dissimilar pathological processes. In this study, we measured the impact of capsaicin (Cap) on these pathological processes using a primary cultured neonatal rat cardiomyocyte in vitro model. The results showed that overproduction of ROS was tightly associated with disturbed GSH/GSSG and NAD+/NADH suppressed mt complex I and III activities, decreased oxygen consumption rates, and elevated extracellular acidification rates. During anoxia or A/R period, these indices interact with each other causing the mitochondrial function to worsen. Cap protected cardiomyocytes against the different stages of A/R injury by rescuing NAD+/NADH, GSH/GSSG, and mt complex I/III activities and cellular energy metabolism. Importantly, Cap-mediated upregulation of 14-3-3η, a protective phosphoserine-binding protein in cardiomyocytes, ameliorated mt function caused by a disruptive redox status and an impaired ETC. In conclusion, redox pair, mt complex I/III, and metabolic equilibrium were significantly different in anoxia alone and A/R injury; Cap through upregulating 14-3-3η plays a protection against the above injury in cardiomyocyte.

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