Baicalein attenuates oxidant stress in cardiomyocytes

2002 ◽  
Vol 282 (3) ◽  
pp. H999-H1006 ◽  
Author(s):  
Zuo-Hui Shao ◽  
Terry L. Vanden Hoek ◽  
Yimin Qin ◽  
Lance B. Becker ◽  
Paul T. Schumacker ◽  
...  
Keyword(s):  
Cell Death ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Ischemia Reperfusion ◽  
Oxidant Stress ◽  
Complex Iii ◽  
Ros Generation ◽  
Resonance Spectroscopy ◽  
Iodide Uptake ◽  
Simulated Ischemia

Flavonoids within Scutellaria baicalensis may be potent antioxidants on the basis of our studies of S. baicalensis extract. To further this work, we studied the antioxidative effects of baicalein, a flavonoid component of S. baicalensis, in a chick cardiomyocyte model of reactive oxygen species (ROS) generation during hypoxia, simulated ischemia-reperfusion, or mitochondrial complex III inhibition with antimycin A. Oxidant stress was measured by oxidation of the intracellular probes 2′,7′-dichlorofluorescin diacetate and dihydroethidium. Viability was assessed by propidium iodide uptake. Baicalein attenuated oxidant stress during all conditions studied and acted within minutes of treatment. For example, baicalein given only at reperfusion dose dependently attenuated the ROS burst at 5 min after 1 h of simulated ischemia. It also decreased subsequent cell death at 3 h of reperfusion from 52.3 ± 2.5% in untreated cells to 29.4 ± 3.0% (with return of contractions; P < 0.001). In vitro studies using electron paramagnetic resonance spectroscopy with the spin trap 5-methoxycarbonyl-5-methyl-1-pyrroline- N-oxide revealed that baicalein scavenges superoxide but does not mimic the effects of superoxide dismutase. We conclude that baicalein can scavenge ROS generation in cardiomyocytes and that it protects against cell death in an ischemia-reperfusion model when given only at reperfusion.

Abstract P133: Role of Akt and p38 in Oxidant Stress Injury and Hypothermic Protection in Murine Cardiomyocytes

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kimberly R Wojcik ◽  
Zuo-Hui Shao ◽  
Chang-Qing Li ◽  
Kimm J Hamann ◽  
Terry L Vanden Hoek
Keyword(s):  
Cell Death ◽  
Cardiac Arrest ◽  
Cell Injury ◽  
Ischemia Reperfusion ◽  
Oxidant Stress ◽  
Ros Generation ◽  
Akt Inhibitor ◽  
Stress Injury ◽  
P38 Inhibitor ◽  
Sb 203580

Cardiac arrest is an ischemia/reperfusion (I/R) disease characterized by oxidant generation, inflammation, and cell death; and hypothermia (HT) has been shown to improve post-cardiac arrest reperfusion injury. We developed a neonatal mouse cardiomyocyte model of I/R (90 min I + 3 hr R) that demonstrates cell injury associated with increased reactive oxygen species (ROS) generation at reperfusion (as measured by DCFH). Mild HT (32°C) protects mouse cardiomyocytes from I/R injury, and we hypothesize that this protection may be related to the activation of the survival kinase Akt. The Akt inhibitor API-2 (10 ìM) reversed HT protection [32.4 ± 7.1% vs 65.7 ± 6.3% with API-2, p< .01(as measured by PI)] to cell death levels commensurate with normothermic I/R injury (60.7 ± 6.0%). Phospho-Akt (pAkt) levels declined during ischemia, and while both Ser473 and Thr308 were phosphorylated in normothermia and HT within 15 min reperfusion, HT showed an augmented level of pAkt at Thr308. Furthermore, this increase was sustained for the first 30 min of reperfusion. To further study this relationship, murine cardiomyocytes were exposed to exogenous H2O2 to mimic the oxidant stress associated with I/R. Mouse cardiomyocytes demonstrated a dose- and time-dependent activation of Akt to H2O2 that showed maximal activation of both the Ser473 and Thr308 sites within 30 min with 200 ìM H2O2. As in I/R-stimulated cells, the Thr308 site declined to near baseline levels within 1 hr while Ser473 remained elevated. Based on recent findings linking Akt and ROS with p38, we examined the effect of I/R and H2O2 on p38. Mouse cardiomyocytes demonstrated a rapid activation of p-p38 (Thr10/Tyr182) in the context of both stresses. Further, we studied the effect of the Akt inhibitor, API-2, as well as the p38 inhibitor, SB 203580, in H2O2-stimulated cells. As in I/R, API-2 blocked H2O2-induced pAkt, but this inhibitor did not have any effect on p-p38. However, when p38 activation was blocked using SB 203580, pAkt levels decreased by 2 hr. These data suggest that HT is, in part, mediated through Akt and that p38 lies upstream of Akt in the context of oxidant stress. These kinases may act as triggers for the initiation of survival pathways in cardiomyocytes to combat potential damage induced by ROS generation.

scholarly journals Mitochondrial oxidant stress triggers cell death in simulated ischemia–reperfusion

2011 ◽  
Vol 1813 (7) ◽  
pp. 1382-1394 ◽  
Author(s):  
Gabriel Loor ◽  
Jyothisri Kondapalli ◽  
Hirotaro Iwase ◽  
Navdeep S. Chandel ◽  
Gregory B. Waypa ◽  
...  
Keyword(s):  
Cell Death ◽  
Ischemia Reperfusion ◽  
Oxidant Stress ◽  
Simulated Ischemia

scholarly journals Neuronal death during combined intermittent hypoxia/hypercapnia is due to mitochondrial dysfunction

2010 ◽  
Vol 298 (6) ◽  
pp. C1594-C1602 ◽  
Author(s):  
Robert M. Douglas ◽  
Julie Ryu ◽  
Amjad Kanaan ◽  
Maria del Carmen Rivero ◽  
Laura L. Dugan ◽  
...  
Keyword(s):  
Intermittent Hypoxia ◽  
Apoptotic Cell ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Ischemia Reperfusion ◽  
Oxidant Stress ◽  
Resonance Spectroscopy ◽  
Potential Contribution ◽  
Paramagnetic Resonance ◽  
Obstructive Sleep ◽  
Electron Paramagnetic

Breathing-disordered states, such as in obstructive sleep apnea, which are cyclical in nature, have been postulated to induce neurocognitive morbidity in both pediatric and adult populations. The oscillatory nature of intermittent hypoxia, especially when chronic, may mimic the paradigm of ischemia-reperfusion in that tissues and cells are exposed to episodes of low and high O2 and this may lead to oxidant stress. Therefore, we decided to explore the potential contribution of oxidant stress in our intermittent hypoxia/hypercapnia animal model and the role that mitochondria might play in this stress. Neonatal mice were exposed to intermittent hypoxia/hypercapnia for 10 days and 2 wk. Combined intermittent hypoxia/hypercapnia led to a marked increase in apoptotic cell death in the cerebral cortex. Oxygen consumption studies in isolated mitochondria from intermittent hypoxia/hypercapnia-exposed brains demonstrated significant reductions in both state 4 and state 3 respiratory activities by ∼60% and 75%, respectively. Electron paramagnetic resonance spectroscopy registered a significant increase in superoxide production during nonphosphorylating state 4 by 37%, although superoxide leakage during state 3 did not increase upon treatment. Neuronal superoxide-specific dihydroethidium oxidation was also greater in exposed animals. These studies indicate that intermittent hypoxia/hypercapnia leads to oxidative stress due to mitochondrial response within the mouse central nervous system.

Signal Transduction of Opioid-induced Cardioprotection in Ischemia-Reperfusion

2001 ◽  
Vol 94 (6) ◽  
pp. 1082-1088 ◽  
Author(s):  
Bradley C. McPherson ◽  
Zhenhai Yao
Keyword(s):  
Cell Death ◽  
Opioid Receptor ◽  
Oxygen Radicals ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Oxidant Stress ◽  
Katp Channels ◽  
Molecular Probe

Background Morphine reduces myocardial ischemia-reperfusion injury in vivo and in vitro. The authors tried to determine the role of opioid delta1 receptors, oxygen radicals, and adenosine triphosphate-sensitive potassium (KATP) channels in mediating this effect. Methods Chick cardiomyocytes were studied in a flow-through chamber while pH, flow rate, oxygen, and carbon dioxide tension were controlled. Cell viability was quantified by nuclear stain propidium iodide, and oxygen radicals were quantified using molecular probe 2',7'-dichlorofluorescin diacetate. Results Morphine (1 microM) or the selective delta-opioid receptor agonist BW373U86 (10 pM) given for 10 min before 1 h of ischemia and 3 h of reoxygenation reduced cell death (31 +/- 5%, n = 6, and 28 +/- 5%, n = 6 [P &lt; 0.05], respectively, 53 +/- 6%, n = 6, in controls) and generated oxygen radicals before ischemia (724 +/- 53, n = 8, and 742 +/- 75, n = 8 [P &lt; 0.05], respectively, vs. 384 +/- 42, n = 6, in controls, arbitrary units). The protection of morphine was abolished by naloxone, or the selective delta1-opioid receptor antagonist 7-benzylidenenaltrexone. Reduction in cell death and increase in oxygen radicals with BW373U86 were blocked by the selective mitochondrial KATP channel antagonist 5-hydroxydecanoate or diethyldithiocarbamic acid (1,000 microM), which inhibited conversion of O2- to H2O2. The increase in oxygen radicals was abolished by the mitochondrial electron transport inhibitor myxothiazoL Reduction in cell death was associated with attenuated oxidant stress at reperfusion. Conclusion Stimulation of delta1-opioid receptors generates oxygen radicals via mitochondrial KATP channels. This signaling pathway attenuates oxidant stress and cell death in cardiomyocytes.

scholarly journals TRAP1 Provides Protection Against Myocardial Ischemia-Reperfusion Injury by Ameliorating Mitochondrial Dysfunction

2015 ◽  
Vol 36 (5) ◽  
pp. 2072-2082 ◽  
Author(s):  
Peng Zhang ◽  
Yong Lu ◽  
Dong Yu ◽  
Dadong Zhang ◽  
Wei Hu
Keyword(s):  
Cell Death ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Ros Generation ◽  
Complex Activity ◽  
Atp Production

Background: Tumor necrosis factor receptor-associated protein 1 (TRAP1), an essential mitochondrial chaperone is induced in rat hearts following ischemia/reperfusion (I/R), but its role in myocardial I/R injury is unclear. The present study examined the function of TRAP1 in cardiomyocyte hypoxia/reoxygenation injury in vitro and myocardial I/R injury in vivo. Methods: HL-1 cardiomyocytes transfected with TRAP1 or vector were subjected to simulated I/R (SI/R) in vitro. Cell death and mitochondrial function were assessed. Wild type (WT) and TRAP1 knockout (TRAP1 KO) mice were subjected to cardiac I/R in vivo. The infarct size and myocardial apoptosis were determined. WT and TRAP1 KO cardiomyocytes were subjected to SI/R in vitro. Mitochondrial function was assessed. Results: TRAP1 overexpression protects HL-1 cardiomyocytes from SI/R-induced cell death in vitro. The reduced cell death was associated with decreased ROS generation, better-preserved mitochondrial ETC complex activity, membrane potential, and ATP production, as well as delayed mPTP opening. Loss of TRAP1 aggravates SI/R-induced mitochondrial damage in cardiomyocytes in vitro and myocardial I/R injury and apoptosis in vivo. Conclusion: The results of the present study show that TRAP1 provides cardioprotection against myocardial I/R by ameliorating mitochondrial dysfunction.

scholarly journals Attenuation of oxidant stress during reoxygenation by AMP 579 in cardiomyocytes

2001 ◽  
Vol 281 (6) ◽  
pp. H2585-H2589 ◽  
Author(s):  
Zhelong Xu ◽  
Michael V. Cohen ◽  
James M. Downey ◽  
Terry L. Vanden Hoek ◽  
Zhenhai Yao
Keyword(s):  
Cell Death ◽  
Reperfusion Injury ◽  
Oxidant Stress ◽  
Myocardial Reperfusion ◽  
Ros Generation ◽  
Iodide Uptake ◽  
Simultaneous Exposure ◽  
Embryonic Cardiomyocytes ◽  
Dichlorofluorescin Diacetate ◽  
Reactive Oxidant

AMP 579, an adenosine A1/A2 receptor agonist, has a strong anti-infarct effect when administered just before reperfusion. Because oxidative stress has been proposed to contribute to myocardial reperfusion injury, we tested whether AMP 579 can reduce the production of reactive oxidant species (ROS) during reoxygenation in cultured chick embryonic cardiomyocytes. The intracellular fluorescent probe 2′,7′-dichlorofluorescin diacetate (DCFH) was used to detect ROS. The cells were subjected to 60 min of simulated ischemia, followed by either 15 min or 3 h of reoxygenation. AMP 579 (0.5 and 1 μM), when started 10 min before reoxygenation, significantly reduced ROS generation from 4.86 ± 0.30 (arbitrary units) in untreated cells to 2.72 ± 0.31 and 1.85 ± 0.14, respectively ( P < 0.05). Cell death that was assessed by propidium iodide uptake was markedly reduced by AMP 579 (49.6 ± 4.7% of control cells vs. 25.4 ± 2.4%, P < 0.05). In contrast, adenosine did not alter ROS generation or cell death. Attenuation of ROS production by AMP 579 was completely prevented by simultaneous exposure of cells to the selective adenosine A2 antagonist 8-(13-chlorostyryl) caffeine. These results indicate that AMP 579 directly protects cardiomyocytes from reperfusion injury by a mechanism that attenuates intracellular oxidant stress. Furthermore, adenosine could not duplicate these effects.

scholarly journals Evaluation of Biological Toxicity of CdTe Quantum Dots in Trypanosoma cruzi

2020 ◽  
Vol 9 (12) ◽  
pp. e34391211274
Author(s):  
Graziella Santos Martins ◽  
Suzete Araújo Oliveira Gomes ◽  
Sônia Renaux Wanderley Louro ◽  
Eliane Wajnberg ◽  
Odivaldo Cambraia Alves ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Trypanosoma Cruzi ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Semiconductor Nanocrystals ◽  
Growth Curves ◽  
Ros Generation ◽  
Resonance Spectroscopy ◽  
Biological Toxicity

Luminescent semiconductor nanocrystals or quantum dots (QDs) emerge as important fluorescent probes for in vitro and in vivo Trypanosoma cruzi cells studies. However, to ensure applicability to living organisms, several tests still need to be done. Since several toxic events are caused by QDs, such as loss of mitochondrial membrane potential, ROS generation, DNA damage and cell death by autophagy. We performed a review of the literature on mechanisms of cellular uptake, internalization and citotoxicity of nanoparticles including our results about the evaluation of biological toxicity in T. cruzi. We evaluated the possible effects on parasite growth curves in a time - scale of control and incubated cells with different concentrations of CdTe – QDs (0.2; 2.0; 20 and 200µM) to determine the development cells changes. In addition, intracellular ROS were measured by Electron Paramagnetic Resonance Spectroscopy (EPR) technique. According our results, we can infer that the toxic effects of QDs in T. cruzi are dose-dependent and that high levels of ROS are involved in cellular toxicity promoted by higher concentrations of QDs. In summary, parasites labeled with low concentrations of nanoparticles are suitable and can be used as bioimaging tools for living parasites. However, more studies on QDs cytotoxicity need to be carried out.

In vitro Lipolysis as a Tool for the Establishment of IVIVC for Lipid-Based Drug Delivery Systems

2019 ◽  
Vol 16 (8) ◽  
pp. 688-697
Author(s):  
Ravinder Verma ◽  
Deepak Kaushik
Keyword(s):  
Drug Delivery ◽  
Ph Value ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Rapid Screening ◽  
Resonance Spectroscopy ◽  
Fed State ◽  
In Vitro Lipolysis ◽  
Ph Stat

: In vitro lipolysis has emerged as a powerful tool in the development of in vitro in vivo correlation for Lipid-based Drug Delivery System (LbDDS). In vitro lipolysis possesses the ability to mimic the assimilation of LbDDS in the human biological system. The digestion medium for in vitro lipolysis commonly contains an aqueous buffer media, bile salts, phospholipids and sodium chloride. The concentrations of these compounds are defined by the physiological conditions prevailing in the fasted or fed state. The pH of the medium is monitored by a pH-sensitive electrode connected to a computercontrolled pH-stat device capable of maintaining a predefined pH value via titration with sodium hydroxide. Copenhagen, Monash and Jerusalem are used as different models for in vitro lipolysis studies. The most common approach used in evaluating the kinetics of lipolysis of emulsion-based encapsulation systems is the pH-stat titration technique. This is widely used in both the nutritional and the pharmacological research fields as a rapid screening tool. Analytical tools for the assessment of in vitro lipolysis include HPLC, GC, HPTLC, SEM, Cryo TEM, Electron paramagnetic resonance spectroscopy, Raman spectroscopy and Nanoparticle Tracking Analysis (NTA) for the characterization of the lipids and colloidal phases after digestion of lipids. Various researches have been carried out for the establishment of IVIVC by using in vitro lipolysis models. The current publication also presents an updated review of various researches in the field of in vitro lipolysis.

scholarly journals iPLA2β Contributes to ER Stress-Induced Apoptosis during Myocardial Ischemia/Reperfusion Injury

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1446
Author(s):  
Tingting Jin ◽  
Jun Lin ◽  
Yingchao Gong ◽  
Xukun Bi ◽  
Shasha Hu ◽  
...  
Keyword(s):  
Cell Death ◽  
Heart Disease ◽  
Myocardial Ischemia ◽  
Ischemic Heart Disease ◽  
Er Stress ◽  
Ischemia Reperfusion ◽  
Myocardial Ischemia Reperfusion ◽  
Induced Apoptosis

Both calcium-independent phospholipase A2 beta (iPLA2β) and endoplasmic reticulum (ER) stress regulate important pathophysiological processes including inflammation, calcium homeostasis and apoptosis. However, their roles in ischemic heart disease are poorly understood. Here, we show that the expression of iPLA2β is increased during myocardial ischemia/reperfusion (I/R) injury, concomitant with the induction of ER stress and the upregulation of cell death. We further show that the levels of iPLA2β in serum collected from acute myocardial infarction (AMI) patients and in samples collected from both in vivo and in vitro I/R injury models are significantly elevated. Further, iPLA2β knockout mice and siRNA mediated iPLA2β knockdown are employed to evaluate the ER stress and cell apoptosis during I/R injury. Additionally, cell surface protein biotinylation and immunofluorescence assays are used to trace and locate iPLA2β. Our data demonstrate the increase of iPLA2β augments ER stress and enhances cardiomyocyte apoptosis during I/R injury in vitro and in vivo. Inhibition of iPLA2β ameliorates ER stress and decreases cell death. Mechanistically, iPLA2β promotes ER stress and apoptosis by translocating to ER upon myocardial I/R injury. Together, our study suggests iPLA2β contributes to ER stress-induced apoptosis during myocardial I/R injury, which may serve as a potential therapeutic target against ischemic heart disease.

scholarly journals miR-182-5p and miR-378a-3p regulate ferroptosis in I/R-induced renal injury

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Chenguang Ding ◽  
Xiaoming Ding ◽  
Jin Zheng ◽  
Bo Wang ◽  
Yang Li ◽  
...  
Keyword(s):  
Cell Death ◽  
Renal Injury ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Luciferase Reporter ◽  
Renal Tubular Cell ◽  
In Cells

Abstract Renal tubular cell death is the key factor of the pathogenesis of ischemia/reperfusion (I/R) kidney injury. Ferroptosis is a type of regulated cell death (RCD) found in various diseases. However, the underlying molecular mechanisms related to ferroptosis in renal I/R injury remain unclear. In the present study, we investigated the regulatory role of microRNAs on ferroptosis in I/R-induced renal injury. We established the I/R-induced renal injury model in rats, and H/R induced HK-2 cells injury in vitro. CCK-8 was used to measure cell viability. Fe2+ and ROS levels were assayed to evaluate the activation of ferroptosis. We performed RNA sequencing to profile the miRNAs expression in H/R-induced injury and ferroptosis. Western blot analysis was used to detect the protein expression. qRT-PCR was used to detect the mRNA and miRNA levels in cells and tissues. We further used luciferase reporter assay to verify the direct targeting effect of miRNA. We found that ischemia/reperfusion-induced ferroptosis in rat’s kidney. We identified that miR-182-5p and miR-378a-3p were upregulated in the ferroptosis and H/R-induced injury, and correlates reversely with glutathione peroxidases 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression in renal I/R injury tissues, respectively. In vitro studies showed that miR-182-5p and miR-378a-3p induced ferroptosis in cells. We further found that miR-182-5p and miR-378a-3p regulated the expression of GPX4 and SLC7A11 negatively by directly binding to the 3′UTR of GPX4 and SLC7A11 mRNA. In vivo study showed that silencing miR-182-5p and miR-378a-3p alleviated the I/R-induced renal injury in rats. In conclusion, we demonstrated that I/R induced upregulation of miR-182-5p and miR-378a-3p, leading to activation of ferroptosis in renal injury through downregulation of GPX4 and SLC7A11.

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