Hydrogen sulfide contributes to cardioprotection during ischemia–reperfusion injury by opening KATP channels

2007 ◽  
Vol 85 (12) ◽  
pp. 1248-1253 ◽  
Author(s):  
Zhifei Zhang ◽  
Haixia Huang ◽  
Ping Liu ◽  
Chaoshu Tang ◽  
Jun Wang

The present study was undertaken to investigate the protective effect of H2S against myocardial ischemia–reperfusion (I/R) injury and its possible mechanism by using isolated heart perfusion and patch clamp recordings. Rat isolated hearts were Langendorff-perfused and subjected to a 30-minute ischemia insult followed by a 30-minute reperfusion. The heart function was assessed by measuring the LVDP, ±dP/dtmax, and the arrhythmia score. The results showed that the treatment of hearts with a H2S donor (40 μmol/L NaHS) during reperfusion resulted in significant improvement in heart function compared with the I/R group (LVDP recovered to 85.0% ± 6.4% vs. 35.0% ± 6.1%, +dP/dtmax recovered to 80.9% ± 4.2% vs. 43.0% ± 6.4%, and –dP/dtmax recovered to 87.4% ± 7.3% vs. 53.8% ± 4.9%; p < 0.01). The arrhythmia scores also improved in the NaHS group compared with the I/R group (1.5 ± 0.2 vs. 4.0 ± 0.4, respectively; p < 0.001). The cardioprotective effect of NaHS during reperfusion could be blocked by an ATP-sensitive potassium channel (KATP) blocker (10 μmol/L glibenclamide). In single cardiac myocytes, NaHS increased the open probability of KATP channels from 0.07 ± 0.03 to 0.15 ± 0.08 after application of 40 μmol/L NaHS and from 0.07 ± 0.03 to 0.36 ± 0.15 after application of 100 μmol/L NaHS. These findings provide the first evidence that H2S increases the open probability of KATP in cardiac myocytes, which may be responsible for cardioprotection against I/R injury during reperfusion.

1999 ◽  
Vol 277 (6) ◽  
pp. H2373-H2380 ◽  
Author(s):  
Elaine J. Tanhehco ◽  
Koji Yasojima ◽  
Patrick L. McGeer ◽  
Ruth A. Washington ◽  
Kenneth S. Kilgore ◽  
...  

Both preconditioning and inhibition of complement activation have been shown to ameliorate myocardial ischemia-reperfusion injury. The recent demonstration that myocardial tissue expresses complement components led us to investigate whether preconditioning affects complement expression in the isolated heart. Hearts from New Zealand White rabbits were exposed to either two rounds of 5 min global ischemia followed by 10 min reperfusion (ischemic preconditioning) or 10 μM of the ATP-dependent K+(KATP) channel opener pinacidil for 30 min (chemical preconditioning) before induction of 30 min global ischemia followed by 60 min of reperfusion. Both ischemic and chemical preconditioning significantly ( P < 0.05) reduced myocardial C1q, C1r, C3, C8, and C9 mRNA levels. Western blot and immunohistochemistry demonstrated a similar reduction in C3 and membrane attack complex protein expression. The KATPchannel blocker glyburide (10 μM) reversed the depression of C1q, C1r, C3, C8, and C9 mRNA expression observed in the pinacidil-treated hearts. The results suggest that reduction of local tissue complement production may be one means by which preconditioning protects the ischemic myocardium.


2003 ◽  
Vol 284 (6) ◽  
pp. H2351-H2359 ◽  
Author(s):  
Edith Hochhauser ◽  
Shaye Kivity ◽  
Daniel Offen ◽  
Nilanjana Maulik ◽  
Hajime Otani ◽  
...  

The role of the proapototic Bax gene in ischemia-reperfusion (I/R) injury was studied in three groups of mice: homozygotic knockout mice lacking the Bax gene (Bax−/−), heterozygotic mice (Bax+/−), and wild-type mice (Bax+/+). Isolated hearts were subjected to ischemia (30 min, 37°C) and then to 120 min of reperfusion. The left ventricular developed force of Bax-deficient vs. Bax+/+ hearts at stabilization and at 120 min of reperfusion was 1,411 ± 177 vs. 1,161 ± 137 mg and 485 ± 69 vs. 306 ± 68 mg, respectively. Superior cardiac function of Bax−/− hearts after I/R was accompanied by a decrease in creatine kinase release, caspase 3 activity, irreversible ischemic injury, and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cardiomyocytes. Electron microscopic evaluation revealed reduced damage to mitochondria and the nuclear chromatin structure in Bax-deficient mice. In the Bax+/− hearts, the damage markers were moderate. The superior tolerance of Bax knockout hearts to I/R injury recommends this gene as a potential target for therapeutic intervention in patients with severe and intractable myocardial ischemia.


Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2388
Author(s):  
Kevin M. Casin ◽  
John W. Calvert

Myocardial ischemia–reperfusion (I/R) injury significantly alters heart function following infarct and increases the risk of heart failure. Many studies have sought to preserve irreplaceable myocardium, termed cardioprotection, but few, if any, treatments have yielded a substantial reduction in clinical I/R injury. More research is needed to fully understand the molecular pathways that govern cardioprotection. Redox mechanisms, specifically cysteine oxidations, are acute and key regulators of molecular signaling cascades mediated by kinases. Here, we review the role of reactive oxygen species in modifying cysteine residues and how these modifications affect kinase function to impact cardioprotection. This exciting area of research may provide novel insight into mechanisms and likely lead to new treatments for I/R injury.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
C N Witt ◽  
C Koentges ◽  
K Pfeil ◽  
L Vogelbacher ◽  
T Pusdrowski ◽  
...  

Abstract Sirtuin 5 (SIRT5) is a mitochondrial NAD+-dependent protein deacylase which regulates the enzymatic activity of numerous mitochondrial proteins due to increased succinylation and malonylation, including enzymes of energy substrate oxidation and mitochondrial antioxidant enzymes. Since energy depletion and mitochondrial oxidative stress contribute to myocardial IR injury, it was our objective to evaluate the potential role of SIRT5 in IR injury. In regular Langendorff heart perfusions, 8 week-old cardiomyocyte-selective SIRT5−/− mice showed no difference in LV developed pressure or dp/dt max compared to wildtype mice. However, recovery of LV developed pressure and dp/dt max following 25 min of ischemia was lower by 34% and 20% in SIRT5−/− mice compared to WT mice, respectively. In contrast, postischemic recovery of cardiac function was not impaired and even improved in mice with cardiomyocyte-selective overexpression of SIRT5 compared to WT mice undergoing IR. Mitochondrial H2O2 generation was significantly increased in SIRT5−/− mice compared to WT mice following IR, and mitochondria-targeted antioxidant treatments (MnTBAP or SS-31) during heart perfusion completely normalized recovery of contractile parameters in SIRT5−/− mice following IR. In conclusion, SIRT5 is not required to maintain cardiac function under physiological conditions. However, lack of SIRT5 aggravates myocardial IR injury, likely by increasing mitochondrial oxidative stress. SIRT5 agonism may thus represent a potential therapeutic strategy to attenuate myocardial IR injury.


Cardiology ◽  
2016 ◽  
Vol 134 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Peng Liu ◽  
Wei You ◽  
Lin Lin ◽  
Yongluan Lin ◽  
Xiuying Tang ◽  
...  

Objective: This study explores the effects of helix B surface peptide (HBSP) on myocardial infarct size (IS), cardiac function, cardiomyocyte apoptosis and oxidative stress damage in mouse hearts subjected to myocardial ischemia-reperfusion injury (MIRI) and also the mechanisms underlying the effects. Method: Male adult mice were subjected to 45 min of ischemia followed by 2 h of reperfusion; 5 min before the reperfusion, they were treated with HBSP or vehicle. MIRI-induced IS, cardiomyocyte apoptosis and cardiac functional impairment were determined and compared. Western blot analysis was then conducted to elucidate the mechanism of HBSP after treatment. Results: HBSP administration before reperfusion significantly reduced the myocardial IS, decreased cardiomyocyte apoptosis, reduced the activities of superoxide dismutase and malondialdehyde and partially preserved heart function. As demonstrated by the Western blot analysis, HBSP after treatment upregulated Akt/GSK-3β/ERK and STAT-3 phosphorylation; these inhibitors, in turn, weakened the beneficial effects of HBSP. Conclusion: HBSP plays a protective role in MIRI in mice by inhibiting cardiomyocyte apoptosis, reducing the MIRI-induced IS, oxidative stress and improving the heart function after MIRI. The mechanism underlying these effects of HBSP is related to the activation of the RISK (reperfusion injury salvage kinase, Akt/GSK-3β/ERK) and SAFE (STAT-3) pathways.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Li-Ming Yu ◽  
Xue Dong ◽  
Jian Zhang ◽  
Zhi Li ◽  
Xiao-Dong Xue ◽  
...  

Endoplasmic reticulum (ER) stress and oxidative stress contribute greatly to myocardial ischemia-reperfusion (MI/R) injury. Naringenin, a flavonoid derived from the citrus genus, exerts cardioprotective effects. However, the effects of naringenin on ER stress as well as oxidative stress under MI/R condition and the detailed mechanisms remain poorly defined. This study investigated the protective effect of naringenin on MI/R-injured heart with a focus on cyclic guanosine monophosphate- (cGMP-) dependent protein kinase (PKG) signaling. Sprague-Dawley rats were treated with naringenin (50 mg/kg/d) and subjected to MI/R surgery with or without KT5823 (2 mg/kg, a selective inhibitor of PKG) cotreatment. Cellular experiment was conducted on H9c2 cardiomyoblasts subjected to simulated ischemia-reperfusion treatment. Before the treatment, the cells were incubated with naringenin (80 μmol/L). PKGIα siRNA was employed to inhibit PKG signaling. Our in vivo and in vitro data showed that naringenin effectively improved heart function while it attenuated myocardial apoptosis and infarction. Furthermore, pretreatment with naringenin suppressed MI/R-induced oxidative stress as well as ER stress as evidenced by decreased superoxide generation, myocardial MDA level, gp91phox expression, and phosphorylation of PERK, IRE1α, and EIF2α as well as reduced ATF6 and CHOP. Importantly, naringenin significantly activated myocardial cGMP-PKGIα signaling while inhibition of PKG signaling with KT5823 (in vivo) or siRNA (in vitro) not only abolished these actions but also blunted naringenin’s inhibitory effects against oxidative stress and ER stress. In summary, our study demonstrates that naringenin treatment protects against MI/R injury by reducing oxidative stress and ER stress via cGMP-PKGIα signaling. Its cardioprotective effect deserves further clinical study.


2006 ◽  
Vol 105 (3) ◽  
pp. 541-549 ◽  
Author(s):  
Jianzhong An ◽  
Samhita S. Rhodes ◽  
Ming Tao Jiang ◽  
Zeljko J. Bosnjak ◽  
Ming Tian ◽  
...  

Background Anesthetic preconditioning (APC) is well known to protect against myocardial ischemia-reperfusion injury. Studies also show the benefit of Na+-Ca2+ exchange inhibition on ischemia-reperfusion injury. The authors tested whether APC plus Na+-Ca2+ exchange inhibitors given just on reperfusion affords additive protection in intact hearts. Methods Cytosolic [Ca2+] was measured by fluorescence at the left ventricular wall of guinea pig isolated hearts using indo-1 dye. Sarcoplasmic reticular Ca2+-cycling proteins, i.e., Ca2+ release channel (ryanodine receptor [RyR2]), sarcoplasmic reticular Ca2+-pump adenosine triphosphatase (SERCA2a), and phospholamban were measured by Western blots. Hearts were assigned to seven groups (n = 8 each): (1) time control; (2) ischemia; (3, 4) 10 microM Na+-Ca2+ exchange inhibitor KB-R7943 (KBR) or 1 microM SEA0400 (SEA), given during the first 10 min of reperfusion; (5) APC initiated by sevoflurane (2.2%, 0.41 +/- 0.03 mm) given for 15 min and washed out for 15 min before ischemia-reperfusion; (6, 7) APC plus KBR or SEA. Results The authors found that APC reduced the increase in systolic [Ca2+], whereas KBR and SEA both reduced the increase in diastolic [Ca2+] on reperfusion. Each intervention improved recovery of left ventricular function. Moreover, APC plus KBR or SEA afforded better functional recovery than APC, KBR, or SEA alone (P &lt; 0.05). Ischemia-reperfusion-induced degradation of major sarcoplasmic reticular Ca2+-cycling proteins was attenuated by APC, but not by KBR or SEA. Conclusions APC plus Na+-Ca2+ exchange inhibition exerts additive protection in part by reducing systolic and diastolic Ca2+ overload, respectively, during ischemia-reperfusion. Less degradation of sarcoplasmic reticular Ca2+-cycling proteins may also contribute to cardiac protection.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Mahmood Mozaffari ◽  
Jun Yao Liu ◽  
Babak Baban

Programmed Death-1 (PD-1) and its ligand, PDL-1, are expressed on immune cells and have emerged as negative regulators of immune and inflammatory mechanisms. Aside from the contribution of systemic immune and inflammatory mechanisms to myocardial ischemia reperfusion (IR) injury, isolated heart studies have shown that the myocardium is capable of mounting a robust inflammatory response to an IR insult. However, potential involvement of PD-1/PDL-1 in the setting of cardiac IR injury is not established. We tested the hypothesis that an IR insult downregulates PD-1/PDL-1 pathway thereby exacerbating the inflammatory response and cell death. According, Langendorff-perfused rat hearts were subjected to 40 min of ischemia and 15 min of reperfusion; normoxic hearts served as controls. Thereafter, cardiac cells were prepared and subjected to flow-cytometry-based assays. The ischemic-reperfused hearts displayed a marked increase in the pro-inflammatory cytokine interleukin-17 in association with disruption of mitochondrial membrane potential (JC-1 assay) and apoptotic and necrotic cell death. Importantly, the ischemic-reperfused hearts showed a significant increase in PD-1 and PDL-1 positive cells. The results suggest that cardiac PD-1/ PDL-1 pathway likely constitutes an endogenous mechanism whose upregulation in the ischemic-reperfused heart curbs the inflammatory response and associated tissue injury.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Fuwen Huang ◽  
Jingting Mai ◽  
Jingwei Chen ◽  
Yinying He ◽  
Xiaojun Chen

AbstractThe myocardial infarction is the main cause of morbidity and mortality in cardiovascular diseases around the world. Although the timely and complete reperfusion via Percutaneous Coronary Intervention (PCI) or thrombolysis have distinctly decreased the mortality of myocardial infarction, reperfusion itself may lead to supererogatory irreversible myocardial injury and heart function disorders, namely ischemia-reperfusion (I/R) injury. Extensive studies have indicated that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), play important roles in the progress of myocardial I/R injury, which is closely correlative with cardiomyocytes autophagy. Moreover, autophagy plays an important role in maintaining homeostasis and protecting cells in the myocardial ischemia reperfusion and cardiomyocyte hypoxia-reoxygenation (H/R) progress. In this review, we first introduced the biogenesis and functions of ncRNAs, and subsequently summarized the roles and relevant molecular mechanisms of ncRNAs regulating autophagy in myocardial I/R injury. We hope that this review in addition to develop a better understanding of the physiological and pathological roles of ncRNAs, can also lay a foundation for the therapies of myocardial I/R injury, and even for other related cardiovascular diseases.


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