scholarly journals Naringin Effectively Protects Cardiomyocytes Against Hypoxia/Reoxygenation Injury

Author(s):  
Vu Thi Thu ◽  
Ngo Thi Hai Yen

This study was conducted to evaluate the protective effect of Naringin (NAR) on H9C2 cardiomyocytes in hypoxia/reoxygenation (HR) injury in vitro induced by the hypoxia chamber. Methods: H9C2 cells were grown under normal (control) and HR conditions. The viability, cardiolipin content and mitochondrial membrane potential of H9C2 cells in experimental groups were analyzed by using suitable kits. Results: The obtained results showed that the addition of Naringin (16÷160 µM) significantly increased the survival rate of H9C2 cells under HR conditions. In particular, NAR had the highest efficiency in preserving mitochondrial function at concentrations of 80 µM and 160 µM. In HR-exposed H9C2 cell group, the cardiolipin content and mitochondrial membrane potential values of H9C2 cells were decreased sharply with that of control (71,64±1,37% and 68,12±2,78%, p<0,05). Interestingly, mitochondrial cardiolipin contents were signigicantly increased in H9C2 cells post-hypoxic treated wtih NAR at dose of 80 µM 160 µM to 87,76±1,89% and 81,09±1,21%. Additionally, post-hypoxic supplementation of NAR at concentration of 80 µM and 160 µM effectively increased mitochondrial membrane potential values. Conclusion: The obtained results are preliminary data on the effects of NAR in protecting mitochondrial-targeted cardiomyocytes against HR injury.

2015 ◽  
Vol 309 (4) ◽  
pp. H625-H633 ◽  
Author(s):  
Brenda Cordeiro ◽  
Dmitry Terentyev ◽  
Richard T. Clements

Mitochondrial Ca2+-activated large-conductance K+ (BKCa) channels are thought to provide protection during ischemic insults in the heart. Rottlerin (mallotoxin) has been implicated as a potent BKCa activator. The purpose of this study was twofold: 1) to investigate the efficacy of BKCa channel activation as a cardioprotective strategy during ischemic cardioplegic arrest and reperfusion (CP/R) and 2) to assess the specificity of rottlerin for BKCa channels. Wild-type (WT) and BKCa knockout (KO) mice were subjected to an isolated heart model of ischemic CP/R. A mechanism of rottlerin-induced cardioprotection was also investigated using H9c2 cells subjected to in vitro CP/reoxygenation and assessed for mitochondrial membrane potential and reactive oxygen species (ROS) production. CP/R decreased left ventricular developed pressure, positive and negative first derivatives of left ventricular pressure, and coronary flow (CF) in WT mice. Rottlerin dose dependently increased the recovery of left ventricular function and CF to near baseline levels. BKCa KO hearts treated with or without 500 nM rottlerin were similar to WT CP hearts. H9c2 cells subjected to in vitro CP/R displayed reduced mitochondrial membrane potential and increased ROS generation, both of which were significantly normalized by rottlerin. We conclude that activation of BKCa channels rescues ischemic damage associated with CP/R, likely via effects on improved mitochondrial membrane potential and reduced ROS generation.


2005 ◽  
Vol 289 (1) ◽  
pp. H477-H487 ◽  
Author(s):  
Qi Hou ◽  
Yi-Te Hsu

The proapoptotic protein Bax plays an important role in cardiomyocytic cell death. Ablation of this protein has been shown to diminish cardiac damage in Bax-knockout mice during ischemia-reperfusion. Presently, studies of Bax-mediated cardiac cell death examined primarily the expression levels of Bax and its prosurvival factor Bcl-2 rather than the localization of this protein, which dictates its function. Using immunofluorescence labeling, we have shown that in neonatal rat cardiomyocytes and in H9c2 cardiomyoblasts, Bax translocates from cytosol to mitochondria upon the induction of apoptosis by hypoxia-reoxygenation-serum withdrawal and by the presence of the free-radical inducer menadione. Also, we found that Bax translocation to mitochondria was associated with the exposure of an NH2-terminal epitope, and that this translocation could be partially blocked by the prosurvival factors Bcl-2 and Bcl-XL. To visualize the translocation of Bax in living cells, we have developed an H9c2 cell line that stably expresses green fluorescent protein (GFP)-tagged Bax. This cell line has GFP-Bax localized primarily in the cytosol in the absence of apoptotic inducers. Upon induction of apoptosis by a number of stimuli, including menadione, staurosporine, sodium nitroprusside, and hypoxia-reoxygenation-serum withdrawal, we could observe the translocation of Bax from cytosol to mitochondria. This translocation was not affected by retinoic acid-induced differentiation of H9c2 cells. Additionally, this translocation was associated with loss of mitochondrial membrane potential, release of cytochrome c, and fragmentation of nuclei. Finally, using a tetramethylrhodamine-based dye, we have shown that a rapid screening process based on the loss of mitochondrial membrane potential could be developed to monitor GFP-Bax translocation to mitochondria. Overall, the GFP-Bax-stable H9c2 cell line that we have developed represents a unique tool for examining Bax-mediated apoptosis, and it could be of great importance in screening therapeutic compounds that could block Bax translocation to mitochondria to attenuate apoptosis.


2020 ◽  
Author(s):  
Saijun Zhou ◽  
Zhenxing Meng ◽  
Shumin Xiao ◽  
Ting Cheng ◽  
Shuai Huang ◽  
...  

Abstract BackgroundMyocardial ischemia/reperfusion (I/R) injury is one of the most important reasons for death of coronary heart disease after vascular recanalization. New evidences have shown that β2-glycoprotein I (β2GPI) plays a protective role in cardiovascular diseases. This study aims to evaluate the effects of reduced β2GPI (R-β2GPI), one form of β2GPI, on myocardial I/R injury, and to explore related mechanisms. MethodsThe in vivo myocardial I/R models of Sprague Dawley rats and in vitro hypoxia/reoxygenation(H/R) models of H9c2 cells were established. The myocardial infarction and morphological changes in SD rats were measured by the TTC staining and HE staining. Creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) levels in plasma were detected by ELISA Assay kit. Terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method and caspase-3 colorimetric assay kit were used to determine myocardial apoptosis. Intracellular reactive oxygen species (ROS) generation and mitochondrial membrane potential of H9c2 cells were measured by fluorescent probe DCFH-DA and JC-1 fluorescent staining respectively. To evaluate cell damage, cell viability was assessed by determining the release of lactate dehydrogenase (LDH). The ratio of Bcl-2/Bax at mRNA level was detected by reverse transcription-polymerase chain reaction (RT-PCR). Western blot analysis was used to detect the expression levels of total Akt and phosphorylated Akt as well as the expression levels of total GSK-3βand phosphorylated GSK-3β in H9c2 cells. ResultsOur results suggested that R-β2GPI improved I/R model rats’ heart function, decreased infarct size, reduced serum CK-MB, cTnI levels, cell apoptosis and caspase3 activity. In vitro, R-β2GPI decreased LDH leakage, reduced ROS generation, maintained mitochondrial membrane potential and increased bcl-2/bax mRNA ratio; increased phosphorylation of Akt and GSK-3β in H9c2 cells following Hypoxia/Reoxygenation (H/R) jnjury. ConclusionR-β2GPI alleviated myocardial I/R (or H/R) injury by reducing oxidative stress and inhibiting mitochondrial apoptotic pathway via increasing the phosphorylation of Akt/GSK-3β.


2021 ◽  
Vol 11 ◽  
Author(s):  
Haiping Ma ◽  
Yongjie Li ◽  
Tianliang Hou ◽  
Jing Li ◽  
Long Yang ◽  
...  

Subject: Cardiovascular disease, as a very common and serious coexisting disease in diabetic patients, and is one of the risk factors that seriously affect the prognosis and complications of surgical patients. Previous studies have shown that sevoflurane post-conditioning (SPostC) exerts a protective effect against myocardial ischemia/reperfusion injury by HIF-1α, but the protective effect is weakened or even disappeared under hyperglycemia. This study aims to explore whether regulating the HIF-1α/MIF/AMPK signaling pathway can restore the protective effect and reveal the mechanism of SPostC on cardiomyocyte hypoxia/reoxygenation injury under high glucose conditions.Methods: H9c2 cardiomyocytes were cultured in normal and high-concentration glucose medium to establish a hypoxia/reoxygenation (H/R) injury model of cardiomyocytes. SPostC was performed with 2.4% sevoflurane for 15 min before reoxygenation. Cell damage was determined by measuring cell viability, lactate dehydrogenase activity, and apoptosis; Testing cell energy metabolism by detecting reactive oxygen species (ROS) generation, ATP content and mitochondrial membrane potential; Analysis of the change of HIF-1α, MIF and AMPKα mRNA expression by RT-PCR. Western blotting was used to examine the expression of HIF-1α, MIF, AMPKα and p-AMPKα proteins. HIF-1α and MIF inhibitors and agonists were administered 40 min before hypoxia.Results: 1) SPostC exerts a protective effect by increasing cell viability, reducing LDH levels and cell apoptosis under low glucose (5 μM) after undergoing H/R injury; 2) High glucose concentration (35 μM) eliminated the cardioprotective effect of SPostC, which is manifested by a significantly decrease in the protein and mRNA expression level of the HIF-1α/MIF/AMPK signaling pathway, accompanied by decreased cell viability, increased LDH levels and apoptosis, increased ROS production, decreased ATP synthesis, and decreased mitochondrial membrane potential; 3. Under high glucose (35 μM), the expression levels of HIF-1α and MIF were up-regulated by using agonists, which can significantly increase the level of p-AMPKα protein, and the cardioprotective effect of SPostC was restored.Conclusion: The signal pathway of HIF-1α/MIF/AMPK of H9c2 cardiomyocytes may be the key point of SPostC against H/R injure. The cardioprotective of SPostC could be restored by upregulating the protein expression of HIF-1α and MIF under hyperglycemia.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Richard T Clements ◽  
Brenda Cordeiro

Introduction: BKCa channels are thought to provide protection during ischemic insults in the heart. Rottlerin, has been implicated as a potent BKCa activator, however this has not been firmly established. The purpose of this study was two fold: 1) assess the specificity of rottlerin for BKCa channels and 2) investigate the efficacy of BKCa channel activation as a cardioprotective agent during cardioplegia/reperfusion (CP/R). Methods: Wild type and BKCa knock-out mice with and without rottlerin (only administered in CP) were subjected to an isolated heart model of CP/R. Hearts were perfused for 30 min at 37C (baseline), followed by intermittent cold crystalloid cardioplegia (intermittent St Thomas II, 10C), and normothermic, normoxic, reperfusion for 30 min. In additional studies, mechanism of rottlerin-induced cardioprotection was investigated using H9c2 cells subjected to in vitro CP/reoxygenation and assessed for mitochondrial membrane potential (TMRE) and ROS (DCFDA) production. Results: CP and 30 min reperfusion decreased LVDP (58.7 +/- 5 % baseline, n=8 ), +/- dP/dt ( 71.1+/- 6.4, 59.2 +/-6.6, % baseline respectively) and coronary flow (CF) (66.8+/-7.4, %baseline) in wild type mice. Rottlerin, (100 (n=3), 500 nM (n=5)) delivered in the CP solution dose dependently increased the recovery of LV function and CF to near baseline levels (500 nM rottlerin, LVDP: 94.1+/- 2.3, +/-dPdt: 99.6 +/- 7.2, 111.0+/- 15.0, % baseline, and CF: 128.9 +/-30.0 %baseline ). BKCa KO hearts treated with (n=4)or without (n=3) 500nM rottlerin, were similar to wt CP hearts, showing no improved cardioprotection (BKCa KO + 500 nM rott: LVDP: 57.7+/- 4.0, +/-dP/dt 69.5 +/-12.0, 59.8+/- 4.9, and CF 73 +/- 6.7). H9c2 cells subjected to in vitro CP/R, displayed reduced mitochondrial membrane potential (39% +/-.09 % decrease relative to control, p<.01) and increased ROS generation (50%+/-.04 increase, p<.01), both of which were dose dependently normalized by rottlerin (100 nM-1 uM) (minimum n=8). Conclusions: Activation of BKCa channels profoundly rescues ischemic damage associated with CP, likely via mitochondrial effects on improved mitochondrial membrane potential and reduced ROS generation.


2014 ◽  
Vol 556-562 ◽  
pp. 610-614
Author(s):  
Shu Liang Song ◽  
Wei Wang ◽  
Xiao Chen Wang ◽  
Hao Liang ◽  
Yun Shan Wang ◽  
...  

In this study the effect of fucoidan SJP-3 extracted from Stichopus Japonicus was used to evaluate the protective effect on PC12 cells with hypoxia/reoxygenation injury. SJP-3 can stabilize the mitochondrial membrane potential and resistant Cyt-C/mitochondrial apoptotic pathway via increasing the Bcl-2 expression and decreasing expression of the Bax, caspase-3, caspase-9 suggesting that SJP-3 may exert a protective effects on neural cells with hypoxia/reoxygenation injury through the protection of mitochondria, the stability of mitochondrial membrane potential and inhibition of mitochondrial apoptosis pathway.


2021 ◽  
Vol 9 (2) ◽  
pp. 320
Author(s):  
Wilmer Alcazar ◽  
Sami Alakurtti ◽  
Maritza Padrón-Nieves ◽  
Maija Liisa Tuononen ◽  
Noris Rodríguez ◽  
...  

Herein, we evaluated in vitro the anti-leishmanial activity of betulin derivatives in Venezuelan isolates of Leishmania amazonensis, isolated from patients with therapeutic failure. Methods: We analyzed promastigote in vitro susceptibility as well as the cytotoxicity and selectivity of the evaluated compounds. Additionally, the activity of selected compounds was determined in intracellular amastigotes. Finally, to gain hints on their potential mechanism of action, the effect of the most promising compounds on plasma and mitochondrial membrane potential, and nitric oxide and superoxide production by infected macrophages was determined. Results: From the tested 28 compounds, those numbered 18 and 22 were chosen for additional studies. Both 18 and 22 were active (GI50 ≤ 2 µM, cytotoxic CC50 > 45 µM, SI > 20) for the reference strain LTB0016 and for patient isolates. The results suggest that 18 significantly depolarized the plasma membrane potential (p < 0.05) and the mitochondrial membrane potential (p < 0.05) when compared to untreated cells. Although neither 18 nor 22 induced nitric oxide production in infected macrophages, 18 induced superoxide production in infected macrophages. Conclusion: Our results suggest that due to their efficacy and selectivity against intracellular parasites and the potential mechanisms underlying their leishmanicidal effect, the compounds 18 and 22 could be used as tools for designing new chemotherapies against leishmaniasis.


2021 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Nathan P. Wiederhold

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.


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