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An J, Du Y, Li X, Bao Q, Guo Y, Song Y, Jia Y. Myocardial protective effect of sacubitril-valsartan on rats with acute myocardial infarction. Perfusion 2021; 37:208-215. [PMID: 33522428 DOI: 10.1177/0267659121990572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The purpose of this study was to explore the effect of sacubitril-valsartan on rats with acute myocardial infarction. METHODS Sprague-dawley rats were randomly divided into six groups. Rats in Group A and B were threaded without deligation and treated with valsartan (34 mg/kg) or sacubitril-valsartan (68 mg/kg) after operation. Rats in Group C and D were given the two drugs (34 mg/kg, 68 mg/kg) after ligation of the left anterior descending branch for 40 minutes. Rats in Group E and F were restored the blood of the coronary artery after ligation, and given the two drugs (34 mg/kg, 68 mg/kg) at the same time. N-terminal pro-brain natriuretic peptide, high sensitivity troponin T, aldosterone and Cyclic guanosine monophosphate were measured and Color Doppler echocardiography was performed. Six weeks later, the rats were killed, the hearts were weighed and stained with Masson staining. RESULTS Compared with Group A and B, the levels of N-terminal pro-brain natriuretic peptide, high sensitivity troponin T, aldosterone and Cyclic guanosine monophosphate in other groups were significantly increased (p < 0.05). Before treatment, the left ventricular end diastolic diameter and left ventricular end systolic diameter were similar in each group. After treatment, the levels of left ventricular end diastolic diameter and left ventricular end systolic diameter, and collagen fiber range stained with blue in other groups were significantly increased in comparison with Group A and B (p < 0.05). In addition, the left ventricular volume and collagen fiber range stained with blue were notably decreased, the levels of ejection fraction (EF) were increased in sacubitril-valsartan groups in comparison with valsartan groups (p < 0.05). CONCLUSION Early application of sacubitril-valsartan has a protective effect on rats with acute myocardial infarction.
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Affiliation(s)
- Jian An
- Department of Cardiology, Cardiovascular Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China
| | - Ye Du
- Internal Medicine Department, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Xiaohong Li
- Department of Cardiology, Cardiovascular Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China
| | - Qingbo Bao
- Department of Cardiology, Cardiovascular Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yanqing Guo
- Department of Cardiology, Cardiovascular Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yang Song
- Department of Cardiology, Cardiovascular Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yongping Jia
- Department of Cardiology, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
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Zhu P, Hu S, Jin Q, Li D, Tian F, Toan S, Li Y, Zhou H, Chen Y. Ripk3 promotes ER stress-induced necroptosis in cardiac IR injury: A mechanism involving calcium overload/XO/ROS/mPTP pathway. Redox Biol 2018; 16:157-168. [PMID: 29502045 PMCID: PMC5952878 DOI: 10.1016/j.redox.2018.02.019] [Citation(s) in RCA: 286] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/18/2018] [Accepted: 02/19/2018] [Indexed: 12/16/2022] Open
Abstract
Receptor-interacting protein 3 (Ripk3)-mediated necroptosis contributes to cardiac ischaemia-reperfusion (IR) injury through poorly defined mechanisms. Our results demonstrated that Ripk3 was strongly upregulated in murine hearts subjected to IR injury and cardiomyocytes treated with LPS and H2O2. The higher level of Ripk3 was positively correlated to the infarction area expansion, cardiac dysfunction and augmented cardiomyocytes necroptosis. Function study further illustrated that upregulated Ripk3 evoked the endoplasmic reticulum (ER) stress, which was accompanied with an increase in intracellular Ca2+ level ([Ca2+]c) and xanthine oxidase (XO) expression. Activated XO raised cellular reactive oxygen species (ROS) that mediated the mitochondrial permeability transition pore (mPTP) opening and cardiomyocytes necroptosis. By comparison, genetic ablation of Ripk3 abrogated the ER stress and thus blocked the [Ca2+]c overload-XO-ROS-mPTP pathways, favouring a pro-survival state that ultimately resulted in the inhibition of cardiomyocytes necroptosis in the setting of cardiac IR injury. In summary, the present study helps to elucidate how necroptosis is mediated by ER stress, via the calcium overload /XO/ROS/mPTP opening axis. ER stress is activated by Ripk3 in cardiac IR injury. ER stress induces calcium overload which triggers XO-dependent ROS overproduction. ROS outburst promotes mPTP opening that accounts for the necroptosis. Inhibiting ER stress favors cardiomyocytes survival and protects cardiac function.
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Affiliation(s)
- Pingjun Zhu
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Shunying Hu
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Qinhua Jin
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Dandan Li
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Feng Tian
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Sam Toan
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521 USA
| | - Yang Li
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Hao Zhou
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071 USA.
| | - Yundai Chen
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China.
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Penna C, Tullio F, Femminò S, Rocca C, Angelone T, Cerra MC, Gallo MP, Gesmundo I, Fanciulli A, Brizzi MF, Pagliaro P, Alloatti G, Granata R. Obestatin regulates cardiovascular function and promotes cardioprotection through the nitric oxide pathway. J Cell Mol Med 2017; 21:3670-3678. [PMID: 28744974 PMCID: PMC5706590 DOI: 10.1111/jcmm.13277] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/15/2017] [Indexed: 02/06/2023] Open
Abstract
Patients with ischaemic heart disease or chronic heart failure show altered levels of obestatin, suggesting a role for this peptide in human heart function. We have previously demonstrated that GH secretagogues and the ghrelin gene-derived peptides, including obestatin, exert cardiovascular effects by modulating cardiac inotropism and vascular tone, and reducing cell death and contractile dysfunction in hearts subjected to ischaemia/reperfusion (I/R), through the Akt/nitric oxide (NO) pathway. However, the mechanisms underlying the cardiac actions of obestatin remain largely unknown. Thus, we suggested that obestatin-induced activation of PI3K/Akt/NO and PKG signalling is implicated in protection of the myocardium when challenged by adrenergic, endothelinergic or I/R stress. We show that obestatin exerts an inhibitory tone on the performance of rat papillary muscle in both basal conditions and under β-adrenergic overstimulation, through endothelial-dependent NO/cGMP/PKG signalling. This pathway was also involved in the vasodilator effect of the peptide, used both alone and under stress induced by endothelin-1. Moreover, when infused during early reperfusion, obestatin reduced infarct size in isolated I/R rat hearts, through an NO/PKG pathway, comprising ROS/PKC signalling, and converging on mitochondrial ATP-sensitive potassium [mitoK(ATP)] channels. Overall, our results suggest that obestatin regulates cardiovascular function in stress conditions and induces cardioprotection by mechanisms dependent on activation of an NO/soluble guanylate cyclase (sGC)/PKG pathway. In fact, obestatin counteracts exaggerated β-adrenergic and endothelin-1 activity, relevant factors in heart failure, suggesting multiple positive effects of the peptide, including the lowering of cardiac afterload, thus representing a potential candidate in pharmacological post-conditioning.
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Affiliation(s)
- Claudia Penna
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.,National Institute of Cardiovascular Research, Bologna, Italy
| | - Francesca Tullio
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Saveria Femminò
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Carmine Rocca
- National Institute of Cardiovascular Research, Bologna, Italy.,Department of Biology, Ecology and E.S., University of Calabria, Rende, CS, Italy
| | - Tommaso Angelone
- National Institute of Cardiovascular Research, Bologna, Italy.,Department of Biology, Ecology and E.S., University of Calabria, Rende, CS, Italy
| | - Maria C Cerra
- National Institute of Cardiovascular Research, Bologna, Italy.,Department of Biology, Ecology and E.S., University of Calabria, Rende, CS, Italy
| | - Maria Pia Gallo
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Iacopo Gesmundo
- Department of Medical Sciences, University of Turin, Turin, Italy
| | | | | | - Pasquale Pagliaro
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy.,National Institute of Cardiovascular Research, Bologna, Italy
| | - Giuseppe Alloatti
- National Institute of Cardiovascular Research, Bologna, Italy.,Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Riccarda Granata
- Department of Medical Sciences, University of Turin, Turin, Italy
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Pagliaro P, Penna C. Redox signalling and cardioprotection: translatability and mechanism. Br J Pharmacol 2015; 172:1974-95. [PMID: 25303224 DOI: 10.1111/bph.12975] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/24/2014] [Accepted: 09/30/2014] [Indexed: 12/13/2022] Open
Abstract
The morbidity and mortality from coronary artery disease (CAD) remain significant worldwide. The treatment for acute myocardial infarction has improved over the past decades, including early reperfusion of culprit coronary arteries. Although it is mandatory to reperfuse the ischaemic territory as soon as possible, paradoxically this leads to additional myocardial injury, namely ischaemia/reperfusion (I/R) injury, in which redox stress plays a pivotal role and for which no effective therapy is currently available. In this review, we report evidence that the redox environment plays a pivotal role not only in I/R injury but also in cardioprotection. In fact, cardioprotective strategies, such as pre- and post-conditioning, result in a robust reduction in infarct size in animals and the role of redox signalling is of paramount importance in these conditioning strategies. Nitrosative signalling and cysteine redox modifications, such as S-nitrosation/S-nitrosylation, are also emerging as very important mechanisms in conditioning cardioprotection. The reasons for the switch from protective oxidative/nitrosative signalling to deleterious oxidative/nitrosative/nitrative stress are not fully understood. The complex regulation of this switch is, at least in part, responsible for the diminished or lack of cardioprotection induced by conditioning protocols observed in ageing animals and with co-morbidities as well as in humans. Therefore, it is important to understand at a mechanistic level the reasons for these differences before proposing a safe and useful transition of ischaemic or pharmacological conditioning. Indeed, more mechanistic novel therapeutic strategies are required to protect the heart from I/R injury and to improve clinical outcomes in patients with CAD.
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Affiliation(s)
- P Pagliaro
- Department of Clinical and Biological Sciences, University of Torino, 10043, Orbassano, Turin, Italy
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Atorvastatin Post-Conditioning Attenuates Myocardial Ischemia Reperfusion Injury via Inhibiting Endoplasmic Reticulum Stress–Related Apoptosis. Shock 2014; 42:365-71. [DOI: 10.1097/shk.0000000000000224] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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6
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Longnus SL, Mathys V, Dornbierer M, Dick F, Carrel TP, Tevaearai HT. Heart transplantation with donation after circulatory determination of death. Nat Rev Cardiol 2014; 11:354-63. [DOI: 10.1038/nrcardio.2014.45] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Parameswaran S, Sharma RK. Altered expression of calcineurin, calpain, calpastatin and HMWCaMBP in cardiac cells following ischemia and reperfusion. Biochem Biophys Res Commun 2013; 443:604-9. [PMID: 24333421 DOI: 10.1016/j.bbrc.2013.12.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 12/03/2013] [Indexed: 11/25/2022]
Abstract
A rise in intracellular myocardial Ca(2+) during cardiac ischemia activates calpain (Calpn) thereby causing damage to myocardial proteins, which leads to myocyte death and consequently to loss of myocardial structure and function. Calcineurin (CaN) interacts with Calpn and causes cellular damage eventually leading to cell death. Calpastatin (Calp) and high molecular weight calmodulin-binding protein (HMWCaMBP) (homolog of Calp), inhibit Calpn activity and thus prevent cell death. CaN stimulation can also result in self-repair of damaged cardiomyocytes. The present study attempts to elucidate the expression of these proteins in cells under pre-ischemic condition (control), following ischemia induction and also reperfusion subsequent to ischemia. For the first time, flow cytometric analysis (FACS) has been used for analyzing protein expression concurrently with viability. We induced ischemia and subsequently reperfusion in 80% confluent cultures of neonatal murine cardiomyocytes (NMCC). Viability following induction was assessed with 7-AAD staining and the cells were simultaneously checked for protein expression by FACS. We observed that ischemia induction results in increased expression of CaN, Calp and Calpn. HMWCaMBP expression was reduced in live cells following ischemia which suggests that there is a poor survival outcome of cells expressing HMWCaMBP thereby making it a potential biomarker for such cells. Most live cells following ischemia expressed CaN pointing towards self-repair and favorable survival outcomes.
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Affiliation(s)
- Sreejit Parameswaran
- Department of Pathology and Laboratory Medicine, Cancer Research Cluster, University of Saskatchewan, Room 4D40, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Rajendra K Sharma
- Department of Pathology and Laboratory Medicine, Cancer Research Cluster, University of Saskatchewan, Room 4D40, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada.
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8
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Redox balance and cardioprotection. Basic Res Cardiol 2013; 108:392. [DOI: 10.1007/s00395-013-0392-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/24/2013] [Accepted: 10/14/2013] [Indexed: 12/11/2022]
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9
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Krenz M, Baines C, Kalogeris T, Korthuis R. Cell Survival Programs and Ischemia/Reperfusion: Hormesis, Preconditioning, and Cardioprotection. ACTA ACUST UNITED AC 2013. [DOI: 10.4199/c00090ed1v01y201309isp044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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10
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Various models of cardiac conditioning in single or sequential periods of ischemia: Comparative effects on infarct size and intracellular signaling. Int J Cardiol 2013; 168:1336-41. [DOI: 10.1016/j.ijcard.2012.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 09/03/2012] [Accepted: 12/05/2012] [Indexed: 01/17/2023]
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Diazoxide postconditioning induces mitochondrial protein S-Nitrosylation and a redox-sensitive mitochondrial phosphorylation/translocation of RISK elements: no role for SAFE. Basic Res Cardiol 2013; 108:371. [DOI: 10.1007/s00395-013-0371-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 06/28/2013] [Accepted: 07/05/2013] [Indexed: 02/07/2023]
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12
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Penna C, Settanni F, Tullio F, Trovato L, Pagliaro P, Alloatti G, Ghigo E, Granata R. GH-releasing hormone induces cardioprotection in isolated male rat heart via activation of RISK and SAFE pathways. Endocrinology 2013; 154:1624-35. [PMID: 23417421 DOI: 10.1210/en.2012-2064] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
GHRH stimulates GH synthesis and release from the pituitary and exerts direct effects in extrapituitary tissues. We have previously shown that pretreatment with GHRH reduces cardiomyocyte apoptosis and improves heart function in isolated rat hearts subjected to ischemia/reperfusion (I/R). Here, we determined whether GHRH given at reperfusion reduces myocardial reperfusion injury and investigated the molecular mechanisms involved in GHRH effects. Isolated rat hearts subjected to I/R were treated at the onset of reperfusion with: 1) GHRH; 2) GHRH+GHRH antagonist JV-1-36; 3) GHRH+mitochondrial ATP-dependent potassium channel inhibitor 5-hydroxydecanoate; 4) GHRH+mitochondrial permeability transition pore opener atractyloside; 5) GHRH+ phosphoinositide 3-kinase/Akt inhibitor Wortmannin (WM); and 6) GHRH+signal transducer and activator of transcription-3 inhibitor tyrphostin-AG490 (AG490). GHRH reduced infarct size at the end of reperfusion and reverted contractility dysfunction in I/R hearts. These effects were inhibited by either JV-1-36, 5-hydroxydecanoate, atractylosid, WM, or AG490. Western blot analysis on left ventricles showed GHRH-induced phosphorylation of either the reperfusion injury salvage kinases (RISK), phosphoinositide 3-kinase/Akt, ERK1/2, and glycogen synthase kinase-3β or signal transducer and activator of transcription-3, as part of the survivor activating factor enhancement (SAFE) pathway. GHRH-induced activation of RISK and SAFE pathways was blocked by JV-1-36, WM, and AG490. Furthermore, GHRH increased the phosphorylation of endothelial nitric oxide synthase and AMP-activated protein kinase and preserved postischemic nicotinamide adenine dinucleotide (NAD(+)) levels. These results suggest that GHRH protects the heart from I/R injury through receptor-mediated mechanisms, leading to activation of RISK and SAFE pathways, which converge on mitochondria and possibly on AMP-activated protein kinase.
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Affiliation(s)
- Claudia Penna
- Department of Clinical and Biological Sciences, University of Torino, 10126 Torino, Italy
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Penna C, Perrelli MG, Pagliaro P. Mitochondrial pathways, permeability transition pore, and redox signaling in cardioprotection: therapeutic implications. Antioxid Redox Signal 2013; 18:556-99. [PMID: 22668069 DOI: 10.1089/ars.2011.4459] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Reperfusion therapy is the indispensable treatment of acute myocardial infarction (AMI) and must be applied as soon as possible to attenuate the ischemic insult. However, reperfusion is responsible for additional myocardial damage likely involving opening of the mitochondrial permeability transition pore (mPTP). A great part of reperfusion injury occurs during the first minute of reperfusion. The prolonged opening of mPTP is considered one of the endpoints of the cascade to myocardial damage, causing loss of cardiomyocyte function and viability. Opening of mPTP and the consequent oxidative stress due to reactive oxygen and nitrogen species (ROS/RNS) are considered among the major mechanisms of mitochondrial and myocardial dysfunction. Kinases and mitochondrial components constitute an intricate network of signaling molecules and mitochondrial proteins, which interact in response to stressors. Cardioprotective pathways are activated by stimuli such as preconditioning and postconditioning (PostC), obtained with brief intermittent ischemia or with pharmacological agents, which drastically reduce the lethal ischemia/reperfusion injury. The protective pathways converging on mitochondria may preserve their function. Protection involves kinases, adenosine triphosphate-dependent potassium channels, ROS signaling, and the mPTP modulation. Some clinical studies using ischemic PostC during angioplasty support its protective effects, and an interesting alternative is pharmacological PostC. In fact, the mPTP desensitizer, cyclosporine A, has been shown to induce appreciable protections in AMI patients. Several factors and comorbidities that might interfere with cardioprotective signaling are considered. Hence, treatments adapted to the characteristics of the patient (i.e., phenotype oriented) might be feasible in the future.
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Affiliation(s)
- Claudia Penna
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, Italy
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Catestatin reduces myocardial ischaemia/reperfusion injury: involvement of PI3K/Akt, PKCs, mitochondrial KATP channels and ROS signalling. Pflugers Arch 2013; 465:1031-40. [PMID: 23319164 DOI: 10.1007/s00424-013-1217-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 01/04/2013] [Accepted: 01/05/2013] [Indexed: 01/07/2023]
Abstract
Catestatin (CST) limits myocardial ischaemia/reperfusion (I/R) injury with unknown mechanisms. Clearly phosphoinositide-3-kinase (PI3K), protein kinase C (PKC) isoforms, including intra-mitochondrial PKCε, mitochondrial KATP (mitoKATP) channels and subsequent reactive oxygen species (ROS)-signalling play important roles in postconditioning cardioprotection, preventing mitochondrial permeability transition pore (mPTP) opening. Therefore, we studied the role of these extra- and intra-mitochondrial factors in CST-induced protection. Isolated rat hearts and H9c2 cells underwent I/R and oxidative stress, respectively. In isolated hearts CST (75nM, CST-Post) given in early-reperfusion significantly reduced infarct size, limited post-ischaemic contracture, and improved recovery of developed left ventricular pressure. PI3K inhibitor, LY-294002 (LY), large spectrum PKC inhibitor, Chelerythrine (CHE), specific PKCε inhibitor (εV1-2), mitoKATP channel blocker, 5-Hydroxydecanoate (5HD) or ROS scavenger, 2-mercaptopropionylglycine (MPG) abolished the infarct-sparing effect of CST. Notably the CST-induced contracture limitation was maintained during co-infusion of 5HD, MPG or εV1-2, but it was lost during co-infusion of LY or CHE. In H9c2 cells challenged with H2O2, mitochondrial depolarization (an index of mPTP opening studied with JC1-probe) was drastically limited by CST (75nM). Our results suggest that the protective signalling pathway activated by CST includes mitoKATP channels, ROS signalling and prevention of mPTP opening, with a central role for upstream PI3K/Akt and PKCs. In fact, all inhibitors completely abolished CST-infarct-sparing effect. Since CST-anti-contracture effect cannot be explained by intra-mitochondrial mechanisms (PKCε activation and mitoKATP channel opening) or ROS signalling, it is proposed that these downstream signals are part of a reverberant loop which re-activates upstream PKCs, which therefore play a pivotal role in CST-induced protection.
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Inhibition of autophagy contributes to ischemic postconditioning-induced neuroprotection against focal cerebral ischemia in rats. PLoS One 2012; 7:e46092. [PMID: 23029398 PMCID: PMC3461004 DOI: 10.1371/journal.pone.0046092] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/27/2012] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Ischemic postconditioning (IPOC), or relief of ischemia in a stuttered manner, has emerged as an innovative treatment strategy to reduce programmed cell death, attenuate ischemic injuries, and improve neurological outcomes. However, the mechanisms involved have not been completely elucidated. Recent studies indicate that autophagy is a type of programmed cell death that plays elusive roles in controlling neuronal damage and metabolic homeostasis. This study aims to determine the role of autophagy in IPOC-induced neuroprotection against focal cerebral ischemia in rats. METHODOLOGY/PRINCIPAL FINDINGS A focal cerebral ischemic model with permanent middle cerebral artery (MCA) occlusion plus transient common carotid artery (CCA) occlusion was established. The autophagosomes and the expressions of LC3/Beclin 1/p62 were evaluated for their contribution to the activation of autophagy. We found that autophagy was markedly induced with the upregulation of LC3/Beclin 1 and downregulation of p62 in the penumbra at various time intervals following ischemia. IPOC, performed at the onset of reperfusion, reduced infarct size, mitigated brain edema, inhibited the induction of LC3/Beclin 1 and reversed the reduction of p62 simultaneously. Rapamycin, an inducer of autophagy, partially reversed all the aforementioned effects induced by IPOC. Conversely, autophagy inhibitor 3-methyladenine (3-MA) attenuated the ischemic insults, inhibited the activation of autophagy, and elevated the expression of anti-apoptotic protein Bcl-2, to an extent comparable to IPOC. CONCLUSIONS/SIGNIFICANCE The present study suggests that inhibition of the autophagic pathway plays a key role in IPOC-induced neuroprotection against focal cerebral ischemia. Thus, pharmacological inhibition of autophagy may provide a novel therapeutic strategy for the treatment of stroke.
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Current World Literature. Curr Opin Nephrol Hypertens 2012; 21:106-18. [DOI: 10.1097/mnh.0b013e32834ee42b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Szabò I, Leanza L, Gulbins E, Zoratti M. Physiology of potassium channels in the inner membrane of mitochondria. Pflugers Arch 2011; 463:231-46. [PMID: 22089812 DOI: 10.1007/s00424-011-1058-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 10/30/2011] [Indexed: 02/06/2023]
Abstract
The inner membrane of the ATP-producing organelles of endosymbiotic origin, mitochondria, has long been considered to be poorly permeable to cations and anions, since the strict control of inner mitochondrial membrane permeability is crucial for efficient ATP synthesis. Over the past 30 years, however, it has become clear that various ion channels--along with antiporters and uniporters--are present in the mitochondrial inner membrane, although at rather low abundance. These channels are important for energy supply, and some are a decisive factor in determining whether a cell lives or dies. Their electrophysiological and pharmacological characterisations have contributed importantly to the ongoing elucidation of their pathophysiological roles. This review gives an overview of recent advances in our understanding of the functions of the mitochondrial potassium channels identified so far. Open issues concerning the possible molecular entities giving rise to the observed activities and channel protein targeting to mitochondria are also discussed.
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Affiliation(s)
- Ildikò Szabò
- Department of Biology, University of Padova, Padova, Italy.
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Abstract
In the heart, ischemia/reperfusion damage occurs mainly during the first minutes of reperfusion. Recently, it has been shown that the heart can be protected against the extension of ischemia/reperfusion injury if brief coronary occlusions are performed just at the beginning of the reperfusion. This procedure has been called postconditioning (PostC). It can also be elicited by pharmacological intervention, that is, pharmacological PostC. In particular, PostC limits infarct size, apoptosis, endothelial dysfunction, neutrophil adherence, and arrhythmias. Similar to preconditioning, PostC may trigger signaling pathways, including reperfusion injury salvage kinase and survivor activating factor enhancement pathways. PostC-induced protection also involves intracellular acidosis and early redox-sensitive mechanisms. However, controversies exist on the nature of receptors and main pathway(s) involved in PostC. Protective pathways activated by PostC appear to converge on mitochondria and, in particular, on mitochondrial permeability transition pores. Preliminary clinical data indicate that drugs targeting mitochondrial permeability transition pore or reperfusion injury salvage kinases may confer benefits to patients with acute myocardial infarction above that provided by myocardial reperfusion alone. Future studies must define the principal protective cascades, the interdependence of the signaling pathways, and the optimal pharmacological target and agent(s) for protection. These studies must also consider the possible confounding effects of comorbidities and their drug treatments.
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Affiliation(s)
- Pasquale Pagliaro
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, Italy
| | - Claudia Penna
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, Italy
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Pagliaro P, Moro F, Tullio F, Perrelli MG, Penna C. Cardioprotective pathways during reperfusion: focus on redox signaling and other modalities of cell signaling. Antioxid Redox Signal 2011; 14:833-50. [PMID: 20649460 DOI: 10.1089/ars.2010.3245] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Post-ischemic reperfusion may result in reactive oxygen species (ROS) generation, reduced availability of nitric oxide (NO•), Ca(2+)overload, prolonged opening of mitochondrial permeability transition pore, and other processes contributing to cell death, myocardial infarction, stunning, and arrhythmias. With the discovery of the preconditioning and postconditioning phenomena, reperfusion injury has been appreciated as a reality from which protection is feasible, especially with postconditioning, which is under the control of physicians. Potentially cooperative protective signaling cascades are recruited by both pre- and postconditioning. In these pathways, phosphorylative/dephosphorylative processes are widely represented. However, cardioprotective modalities of signal transduction also include redox signaling by ROS, S-nitrosylation by NO• and derivative, S-sulfhydration by hydrogen sulfide, and O-linked glycosylation with beta-N-acetylglucosamine. All these modalities can interact and regulate an entire pathway, thus influencing each other. For instance, enzymes can be phosphorylated and/or nitrosylated in specific and/or different site(s) with consequent increase or decrease of their specific activity. The cardioprotective signaling pathways are thought to converge on mitochondria, and various mitochondrial proteins have been identified as targets of these post-transitional modifications in both pre- and postconditioning.
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Affiliation(s)
- Pasquale Pagliaro
- Department of Clinical and Biological Sciences, Università di Torino, Regione Gonzole 10, Orbassano, Turin, Italy.
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