scholarly journals Inhibition of the ubiquitous calpains protects complex I activity and enables improved mitophagy in the heart following ischemia-reperfusion

2019 ◽  
Vol 317 (5) ◽  
pp. C910-C921 ◽  
Author(s):  
Qun Chen ◽  
Jeremy Thompson ◽  
Ying Hu ◽  
Joseph Dean ◽  
Edward J. Lesnefsky
Keyword(s):  
Complex I ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Beclin 1 ◽  
Rat Hearts ◽  
Heart Perfusion ◽  
Interfibrillar Mitochondria ◽  
Perfused Rat Hearts ◽  
Subsarcolemmal Mitochondria ◽  
Complex I Activity

Activation of calpain 1 (CPN1) and calpain 2 (CPN2) contributes to cardiac injury during ischemia (ISC) and reperfusion (REP). Complex I activity is decreased in heart mitochondria following ISC-REP. CPN1 and CPN2 are ubiquitous calpains that exist in both cytosol (cs)-CPN1 and 2 and mitochondria (mit)-CPN1 and 2. Recent work shows that the complex I subunit (NDUFS7) is a potential substrate of the mit-CPN1. We asked whether ISC-REP led to decreased complex I activity via proteolysis of the NDUFS7 subunit via activation of mit-CPN1 and -2. Activation of cs-CPN1 and -2 decreases mitophagy in hepatocytes following ISC-REP. We asked whether activation of cs-CPN1 and -2 impaired mitophagy in the heart following ISC-REP. Buffer-perfused rat hearts underwent 25 min of global ISC and 30 min of REP. MDL-28170 (MDL; 10 µM) was used to inhibit CPN1 and -2. Cytosol, subsarcolemmal mitochondria (SSM), and interfibrillar mitochondria (IFM) were isolated at the end of heart perfusion. Cardiac ISC-REP led to decreased complex I activity with a decrease in the content of NDUFS7 in both SSM and IFM. ISC-REP also resulted in a decrease in cytosolic beclin-1 content, a key component of the autophagy pathway required to form autophagosomes. MDL treatment protected the contents of cytosolic beclin-1 and mitochondrial NDUFS7 in hearts following ISC-REP. These results support that activation of both cytosolic and mitochondrial calpains impairs mitochondria during cardiac ISC-REP. Mitochondria-localized calpains impair complex I via cleavage of a key subunit. Activation of cytosolic calpains contributes to mitochondrial dysfunction by impairing removal of the impaired mitochondria through depletion of a key component of the mitophagy process.

scholarly journals Hydrogen sulfide-mediated cardioprotection against ischemia reperfusion is linked to KATP channel for mitochondrial preservation but not for its distinct preference on interfibrillar mitochondria

2019 ◽  
Vol 14 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Priyadharshini Chandrasekaran ◽  
Sriram Ravindran ◽  
Sri Rahavi Boovarahan ◽  
Gino A. Kurian
Keyword(s):  
Hydrogen Sulfide ◽  
Reperfusion Injury ◽  
Katp Channel ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Rat Hearts ◽  
Significant Difference ◽  
Interfibrillar Mitochondria ◽  
Subsarcolemmal Mitochondria

Hydrogen sulfide has been shown to protect  myocardium against ischemia-reperfusion injury by preserving interfibrillar mitochondria functional activi-ties than subsarcolemmal mitochondria. In this study, the role of the KATP channel in modulating the mitochondrial subpopulations during the cardioprotection mediated by NaSH (H2S donor) was investigated. Isolated rat hearts were treated with mitochondrial KATP channel closer glibenclamide (10 μM)/opener diazoxide (0.8 mM) via Langendorff perfusion apparatus before ischemia-reperfusion. The results showed that NaSH pre-conditioning in presence of glibenclamide significantly improved cardiac recovery without any significant difference between interfibrillar mitochondria and subsarcolemmal mitochondria.  In conclusion, targeting KATP channel may not be good option to target interfibrillar mitochondria/subsarcolemmal mitochondria against ischemia-reperfusion injury.

Ischemic preconditioning does not protect via blockade of electron transport

2007 ◽  
Vol 103 (2) ◽  
pp. 623-628 ◽  
Author(s):  
Christine Tanaka-Esposito ◽  
Qun Chen ◽  
Shadi Moghaddas ◽  
Edward J. Lesnefsky
Keyword(s):  
Electron Transport ◽  
Infarct Size ◽  
Ischemic Preconditioning ◽  
Complex I ◽  
Myocardial Infarct ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Myocardial Infarct Size ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Complex I Activity

Ischemic preconditioning (IPC) before sustained ischemia decreases myocardial infarct size mediated in part via protection of cardiac mitochondria. Reversible blockade of electron transport at complex I immediately before sustained ischemia also preserves mitochondrial respiration and decreases infarct size. We proposed that IPC would attenuate electron transport from complex I as a potential effector mechanism of cardioprotection. Isolated, Langendorff-perfused rat hearts underwent IPC (3 cycles of 5-min 37°C global ischemia and 5-min reperfusion) or were perfused for 40 min without ischemia as controls. Subsarcolemmal (SSM) and interfibrillar (IFM) populations of mitochondria were isolated. IPC did not decrease ADP-stimulated respiration measured in intact mitochondria using substrates that donate reducing equivalents to complex I. Maximally expressed complex I activity measured as rotenone-sensitive NADH:ubiquinone oxidoreductase in detergent-solubilized mitochondria was also unaffected by IPC. Thus the protection of IPC does not occur as a consequence of a partial decrease in complex I activity leading to a decrease in integrated respiration through complex I. IPC and blockade of electron transport both converge on mitochondria as effectors of cardioprotection; however, each modulates mitochondrial metabolism during ischemia by different mechanisms to achieve cardioprotection.

scholarly journals Reoxygenation-dependent decrease in mitochondrial NADH:CoQ reductase (Complex I) activity in the hypoxic/reoxygenated rat heart

1991 ◽  
Vol 274 (1) ◽  
pp. 133-137 ◽  
Author(s):  
L Hardy ◽  
J B Clark ◽  
V M Darley-Usmar ◽  
D R Smith ◽  
D Stone
Keyword(s):  
Respiratory Function ◽  
Complex I ◽  
Ruthenium Red ◽  
Isolated Cardiomyocytes ◽  
Isolated Mitochondria ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Complex I Activity ◽  
Perfused Hearts ◽  
Total Tissue

Reoxygenation of the hypoxic myocardium results in a number of processes, including an O2-dependent increase in total tissue Ca2+ and cell lysis in which mitochondrial electron transport plays a key role. In the present study we have isolated mitochondria from perfused rat hearts subjected to hypoxia and found no change in their respiratory function relative to controls. In contrast, mitochondria isolated immediately after reoxygenation of hypoxic-perfused hearts exhibited a specific and significant decrease in NADH:CoQ reductase (Complex I; EC 1.6.5.3) activity, as measured both polarographically and spectrophotometrically. Isolated cardiomyocytes subjected to a similar protocol of hypoxia/reoxygenation also exhibited a specific decrease in Complex I activity. Myocardial perfusion with media containing Ruthenium Red protected against the reoxygenation-dependent loss of Complex I activity. These observations taken together suggest that mitochondrial Ca2+ uptake on reoxygenation is implicated in the mechanism of the specific loss of Complex I activity.

scholarly journals The Blockade of Transmembrane Cl- Flux Mitigates I/R-Induced Heart Injury via the Inhibition of Calpain Activity

2015 ◽  
Vol 35 (6) ◽  
pp. 2121-2134 ◽  
Author(s):  
Jian-Ying Zhang ◽  
Feng Wu ◽  
Xiao-Ming Gu ◽  
Zhen-Xiao Jin ◽  
Ling-Heng Kong ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Caspase 3 ◽  
Ischemia Reperfusion ◽  
Cardiac Injury ◽  
Calpain Activity ◽  
Rat Hearts ◽  
Marked Decline ◽  
Heart Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Injury Area

Aims: The aim of this study was to determine whether calpain is involved in Cl- -induced myocardial ischemia/reperfusion (I/R) injury. Methods: Isolated rat hearts were subjected to either 45 min of global no-flow ischemia followed by reperfusion or successive perfusion with Ca2+ -free KH solution for 3 min and normal KH solution for 30 min, also known as Ca2+ paradox. Results: The hearts in the I/R group exhibited increases in myocardial injury area, LDH release, caspase 3 activity and apoptotic indices and a marked decline in cardiac performance. As was the case regarding the effects of MDL 28170, an inhibitor of calpain, treatment with 5 µM NPPB, 5 µM DIDS and low Cl- significantly attenuated cardiac injury. Moreover, each of the treatments significantly protected against Ca2+ overload-induced injury in the setting of Ca2+ paradox. The Western blot and immunofluorescence data revealed that there was an increase in the percentages of calpain membrane-positive cells and the numbers of fragments resulting from the calpain-mediated proteolysis of α-fodrin in both the I/R and the Ca2+ paradox, indicating that the activation of calpain occurred. More importantly, these effects were mitigated by the blockade of transmembrane Cl- flux, as was accomplished via MDL 28170. Conclusion: Our results provide evidence that the blockade of transmembrane Cl- flux mitigates I/R-induced cardiac injury via the inhibition of calpain activity. They also indicate that intracellular Ca2+ overload regulates calpain activation in the setting of Cl- -induced injury.

Purinergic Component in the Coronary Vasodilatation to Acetylcholine after Ischemia-Reperfusion in Perfused Rat Hearts

2014 ◽  
Vol 51 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Ángel Luis García-Villalón ◽  
Miriam Granado ◽  
Luis Monge ◽  
Nuria Fernández ◽  
Gonzalo Carreño-Tarragona ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Rat Hearts ◽  
Coronary Vasodilatation ◽  
Perfused Rat Hearts

scholarly journals Cardiac Ischemia and Ischemia/Reperfusion Cause Wide Proteolysis of the Coronary Endothelial Luminal Membrane: Possible Dysfunctions

2011 ◽  
Vol 5 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Blanca Arroyo-Flores ◽  
Erika Chi-Ahumada ◽  
Erika Briones-Cerecero ◽  
Alma Barajas-Espinosa ◽  
Sandra Perez-Aguilar ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Biochemical Changes ◽  
Vascular Endothelial ◽  
Luminal Membrane ◽  
Rat Hearts ◽  
Isoelectric Points ◽  
Perfused Rat Hearts ◽  
Hydrolyzing Enzymes ◽  
2D Gel ◽  
G Protein Coupled

Background: Ischemia and ischemia-reperfusion (I/R) are common clinical insults that disrupt the molecular structure of coronary vascular endothelial luminal membrane (VELM) that result in diverse microvasculature dysfunctions. However, the knowledge of the associated biochemical changes is meager. We hypothesized that ischemia and I/R-induced structural and functional VELM alterations result from biochemical changes. First, these changes need to be described and later the mechanisms behind be identified. Methods: During control conditions, in isolated perfused rat hearts VELM proteins were labeled with biotin. The groups of hearts were: control (C), no flow ischemia (I; 25 min), and I/R (I; 25 min, reperfusion 30 min). The biotinylated luminal endothelial membrane proteins in these three different groups were examined by 2-D electrophoresis and identified. But, it must be kept in mind the proteins were biotin-labeled during control. Results: A comparative analysis of the protein profiles under the 3 conditions following 2D gel electrophoresis showed differences in the molecular weight distribution such that MWC > MWI > MWI/R. Similar analysis for isoelectric points (pHi) showed a shift toward more acidic pHi under ischemic conditions. Of 100 % proteins identified during control 66% and 88% changed their MW-pHi during ischemia and I/R respectively. Among these lost proteins there were 9 proteins identified as adhesins and G-protein coupled receptors. General significance: I and I/R insults alter MW-pHi of most luminal glycocalyx proteins due to the activation of nonspecific hydrolizing mechanisms; suspect metalloproteases and glycanases. This makes necessary the identification of hydrolyzing enzymes reponsible of multiple microvascular dysfunctions in order to maintain the integrity of vascular endothelial membrane. VELM must become a target of future therapeutics.

scholarly journals Real-Time 2-Photon Imaging of Mitochondrial Function in Perfused Rat Hearts Subjected to Ischemia/Reperfusion

Circulation ◽  
2006 ◽  
Vol 114 (14) ◽  
pp. 1497-1503 ◽  
Author(s):  
Madoka Matsumoto-Ida ◽  
Masaharu Akao ◽  
Toshihiro Takeda ◽  
Masashi Kato ◽  
Toru Kita
Keyword(s):  
Real Time ◽  
Mitochondrial Function ◽  
Ischemia Reperfusion ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Photon Imaging

scholarly journals Moderate exercise prevents impaired Ca2+ handling in heart of CO-exposed rat: implication for sensitivity to ischemia-reperfusion

2010 ◽  
Vol 299 (6) ◽  
pp. H2076-H2081 ◽  
Author(s):  
C. Farah ◽  
G. Meyer ◽  
L. André ◽  
J. Boissière ◽  
S. Gayrard ◽  
...  
Keyword(s):  
Exercise Training ◽  
Antioxidant Status ◽  
Ischemia Reperfusion ◽  
Control Group ◽  
Moderate Exercise ◽  
Plasmic Reticulum ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Exercise Induced ◽  
Moderate Exercise Training

Sustained urban carbon monoxide (CO) exposure exacerbates heart vulnerability to ischemia-reperfusion via deleterious effects on the antioxidant status and Ca2+ homeostasis of cardiomyocytes. The aim of this work was to evaluate whether moderate exercise training prevents these effects. Wistar rats were randomly assigned to a control group and to CO groups, living during 4 wk in simulated urban CO pollution (30–100 parts/million, 12 h/day) with (CO-Ex) or sedentary without exercise (CO-Sed). The exercise procedure began 4 wk before CO exposure and was maintained twice a week in standard filtered air during CO exposure. On one set of rats, myocardial ischemia (30 min) and reperfusion (120 min) were performed on isolated perfused rat hearts. On another set of rats, myocardial antioxidant status and Ca2+ handling were evaluated following environmental exposure. As a result, exercise training prevented CO-induced myocardial phenotypical changes. Indeed, exercise induced myocardial antioxidant status recovery in CO-exposed rats, which is accompanied by a normalization of sarco(endo)plasmic reticulum Ca2+-ATPase 2a expression and then of Ca2+ handling. Importantly, in CO-exposed rats, the normalization of cardiomyocyte phenotype with moderate exercise was associated with a restored sensitivity of the myocardium to ischemia-reperfusion. Indeed, CO-Ex rats presented a lower infarct size and a significant decrease of reperfusion arrhythmias compared with their sedentary counterparts. To conclude, moderate exercise, by preventing CO-induced Ca2+ handling and myocardial antioxidant status alterations, reduces heart vulnerability to ischemia-reperfusion.

scholarly journals Antioxidant Solution in Combination with Angiotensin-(1-7) Provides Myocardial Protection in Langendorff-Perfused Rat Hearts

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Michaela Andrä ◽  
Miriam Russ ◽  
Susanne Jauk ◽  
Mariana Lamacie ◽  
Ingrid Lang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Protection ◽  
Ischemia Reperfusion Injury ◽  
Organ Procurement ◽  
Ischemia Reperfusion ◽  
Morphological Alteration ◽  
Organ Shortage ◽  
Cold Ischemia ◽  
Rat Hearts ◽  
Perfused Rat Hearts

As progressive organ shortage in cardiac transplantation demands extension of donor criteria, effort is needed to optimize graft survival. Reactive oxygen and nitrogen species, generated during organ procurement, transplantation, and reperfusion, contribute to acute and late graft dysfunction. The combined application of diverse substances acting via different molecular pathways appears to be a reasonable approach to face the complex mechanism of ischemia reperfusion injury. Thus, an antioxidant solution containing α-ketoglutaric acid, 5-hydroxymethylfurfural, N-acetyl-L-methionine, and N-acetyl-selenium-L-methionine was combined with endogenous angiotensin-(1-7). Its capacity of myocardial protection was investigated in isolated Langendorff-perfused rat hearts subjected to warm and cold ischemia. The physiological cardiac parameters were assessed throughout the experiments. Effects were evaluated via determination of the oxidative stress parameters malondialdehyde and carbonyl proteins as well as immunohistochemical and ultrastructural tissue analyses. It was shown that a combination of 20% (v/v) antioxidant solution and 220 pM angiotensin-(1-7) led to the best results with a preservation of heart tissue against oxidative stress and morphological alteration. Additionally, immediate cardiac recovery (after warm ischemia) and normal physiological performance (after cold ischemia) were recorded. Overall, the results of this study indicate substantial cardioprotection of the novel combination with promising prospective for future clinical use.

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