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Wang J, Wang X, Wan W, Guo Y, Cui Y, Liu W, Guo F. Effects of Shenfu injection on myocardial adenosine receptors in rats with myocardial ischemia-reperfusion postconditioning. Hum Exp Toxicol 2021; 40:S300-S309. [PMID: 34465228 DOI: 10.1177/09603271211041668] [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: 11/16/2022]
Abstract
OBJECTIVE Shenfu injection (SFI) has been reported to have a protection against myocardial ischemia-reperfusion (MI/R) injury. However, the changes of adenosine receptors in MI/R postconditioning when pretreated with SFI are unclear. METHODS Forty-five rats were randomly divided into sham group (sham), MI/R postconditioning group (MI/R-post), low-dose SFI group (1 mL/kg), middle-dose SFI group (2.5 mL/kg), and high-dose SFI group (5 mL/kg). In SFI groups, SFI was intravenously injected before reperfusion, and rats were treated with ischemic postconditioning after ischemia for 30 min. After 24 h of reperfusion, the levels of Ca2+ and cAMP in blood platelets were analyzed. Myocardial infarct volume and myocardial pathology were observed. The levels of adenosine receptor subtypes A1, A2b, and A3 in myocardium were analyzed using immunohistochemistry and Western blot. The oxidative stress-related indicators were also observed. RESULTS Compared with the MI/R-post group, SFI ameliorated the MI/R injury by decreasing the myocardial infarct area, oxidative stress, and concentration of Ca2+ and cAMP (p < 0.01). Pretreatment with SFI enhanced the expression of adenosine receptors A1 and A2b in a dose manner compared with the MI/R-post group. In contrast, the levels of adenosine receptor A3 were increased after MI/R postconditioning compared with the sham group, and its expression continued to increase with the increase of SFI. Furthermore, the oxidative stress reduced with the concentrations of SFI. CONCLUSION These results demonstrated that pretreatment with SFI might regulate the expression of adenosine receptors to improve the MI/R postconditioning.
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Affiliation(s)
- Jie Wang
- Cardiac Intensive Care Unit, 519688Yantaishan Hospital, Yantai, China
| | - Xiaohuan Wang
- Department of Cardiology, 91589Gansu Provincial Hospital, Lanzhou, China
| | - Weiping Wan
- Department of Ultrasound, 519688Yantaishan Hospital, Yantai, China
| | - Yuanying Guo
- School of Public Health, LKS Faculty of Medicine, The University of Hongkang, China
| | - Yanfang Cui
- Department of Ultrasound, 519688Yantaishan Hospital, Yantai, China
| | - Wenbo Liu
- Department of Cardiology, 519688Yantaishan Hospital, Yantai, China
| | - Fangming Guo
- Department of Cardiology, 519688Yantaishan Hospital, Yantai, China
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2
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Haynes JM, Selby JN, Vandekolk TH, Abad IPL, Ho JK, Lieuw WL, Leach K, Savige J, Saini S, Fisher CL, Ricardo SD. Induced Pluripotent Stem Cell-Derived Podocyte-Like Cells as Models for Assessing Mechanisms Underlying Heritable Disease Phenotype: Initial Studies Using Two Alport Syndrome Patient Lines Indicate Impaired Potassium Channel Activity. J Pharmacol Exp Ther 2018; 367:335-347. [PMID: 30104322 DOI: 10.1124/jpet.118.250142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/26/2018] [Indexed: 12/22/2022] Open
Abstract
Renal podocyte survival depends upon the dynamic regulation of a complex cell architecture that links the glomerular basement membrane to integrins, ion channels, and receptors. Alport syndrome is a heritable chronic kidney disease where mutations in α3, α4, or α5 collagen genes promote podocyte death. In rodent models of renal failure, activation of the calcium-sensing receptor (CaSR) can protect podocytes from stress-related death. In this study, we assessed CaSR function in podocyte-like cells derived from induced-pluripotent stem cells from two patients with Alport Syndrome (AS1 & AS2) and a renal disease free individual [normal human mesangial cell (NHMC)], as well as a human immortalized podocyte-like (HIP) cell line. Extracellular calcium elicited concentration-dependent elevations of intracellular calcium in all podocyte-like cells. NHMC and HIP, but not AS1 or AS2 podocyte-like cells, also showed acute reductions in intracellular calcium prior to elevation. In NHMC podocyte-like cells this acute reduction was blocked by the large-conductance potassium channel (KCNMA1) inhibitors iberiotoxin (10 nM) and tetraethylammonium (5 mM), as well as the focal adhesion kinase inhibitor PF562271 (N-methyl-N-(3-((2-(2-oxo-2,3-dihydro-1H-indol-5-ylamino)-5-trifluoromethyl-pyrimidin-4-ylamino)-methyl)-pyridin-2-yl)-methanesulfonamide, 10 nM). Quantitative polymerase chain reaction (qPCR) and immunolabeling showed the presence of KCNMA1 transcript and protein in all podocyte-like cells tested. Cultivation of AS1 podocytes on decellularized plates of NHMC podocyte-like cells partially restored acute reductions in intracellular calcium in response to extracellular calcium. We conclude that the AS patient-derived podocyte-like cells used in this study showed dysfunctional integrin signaling and potassium channel function, which may contribute to podocyte death seen in Alport syndrome.
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Affiliation(s)
- John M Haynes
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - James N Selby
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Teresa H Vandekolk
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Isaiah P L Abad
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Joan K Ho
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Wai-Ling Lieuw
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Katie Leach
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Judith Savige
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Sheetal Saini
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Craig L Fisher
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
| | - Sharon D Ricardo
- Monash Institute of Pharmaceutical Sciences (J.M.H., J.N.S., T.H.V., I.P.L.A., J.K.H., W.-L.L., K.L.) and Department of Anatomy and Developmental Biology (S.S., C.L.F., S.D.R.), Monash University, Victoria, Australia; and Department of Medicine, Royal Melbourne Hospital, Victoria, Australia (J.S.)
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3
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Vyas FS, Nelson CP, Dickenson JM. Role of transglutaminase 2 in A 1 adenosine receptor- and β 2-adrenoceptor-mediated pharmacological pre- and post-conditioning against hypoxia-reoxygenation-induced cell death in H9c2 cells. Eur J Pharmacol 2017; 819:144-160. [PMID: 29208472 DOI: 10.1016/j.ejphar.2017.11.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/20/2017] [Accepted: 11/30/2017] [Indexed: 02/07/2023]
Abstract
Pharmacologically-induced pre- and post-conditioning represent attractive therapeutic strategies to reduce ischaemia/reperfusion injury during cardiac surgery and following myocardial infarction. We have previously reported that transglutaminase 2 (TG2) activity is modulated by the A1 adenosine receptor and β2-adrenoceptor in H9c2 cardiomyoblasts. The primary aim of this study was to determine the role of TG2 in A1 adenosine receptor and β2-adrenoceptor-induced pharmacological pre- and post-conditioning in the H9c2 cells. H9c2 cells were exposed to 8h hypoxia (1% O2) followed by 18h reoxygenation, after which cell viability was assessed by monitoring mitochondrial reduction of MTT, lactate dehydrogenase release and caspase-3 activation. N6-cyclopentyladenosine (CPA; A1 adenosine receptor agonist), formoterol (β2-adrenoceptor agonist) or isoprenaline (non-selective β-adrenoceptor agonist) were added before hypoxia/reoxygenation (pre-conditioning) or at the start of reoxygenation following hypoxia (post-conditioning). Pharmacological pre- and post-conditioning with CPA and isoprenaline significantly reduced hypoxia/reoxygenation-induced cell death. In contrast, formoterol did not elicit protection. Pre-treatment with pertussis toxin (Gi/o-protein inhibitor), DPCPX (A1 adenosine receptor antagonist) or TG2 inhibitors (Z-DON and R283) attenuated the A1 adenosine receptor-induced pharmacological pre- and post-conditioning. Similarly, pertussis toxin, ICI 118,551 (β2-adrenoceptor antagonist) or TG2 inhibition attenuated the isoprenaline-induced cell survival. Knockdown of TG2 using small interfering RNA (siRNA) attenuated CPA and isoprenaline-induced pharmacological pre- and post-conditioning. Finally, proteomic analysis following isoprenaline treatment identified known (e.g. protein S100-A6) and novel (e.g. adenine phosphoribosyltransferase) protein substrates for TG2. These results have shown that A1 adenosine receptor and β2-adrenoceptor-induced protection against simulated hypoxia/reoxygenation occurs in a TG2 and Gi/o-protein dependent manner in H9c2 cardiomyoblasts.
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Affiliation(s)
- Falguni S Vyas
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Carl P Nelson
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - John M Dickenson
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK.
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4
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Randhawa PK, Jaggi AS. Unraveling the role of adenosine in remote ischemic preconditioning-induced cardioprotection. Life Sci 2016; 155:140-6. [PMID: 27157518 DOI: 10.1016/j.lfs.2016.05.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 12/25/2022]
Abstract
Remote ischemic preconditioning (RIPC) induced by alternate cycles of preconditioning ischemia and reperfusion protects the heart against sustained ischemia-reperfusion-induced injury. This technique has been translated to clinical levels in patients undergoing various surgical interventions including coronary artery bypass graft surgery, abdominal aortic aneurysm repair, percutaneous coronary intervention and heart valve surgery. Adenosine is a master regulator of energy metabolism and reduces myocardial ischemia-reperfusion-induced injury. Furthermore, adenosine is a critical trigger as well as a mediator in RIPC-induced cardioprotection and scientists have demonstrated the role of adenosine by showing an increase in its levels in the systemic circulation during RIPC delivery. Furthermore, the blockade of cardioprotective effects of RIPC in the presence of specific adenosine receptor blockers and transgenic animals with targeted ablation of A1 receptors has also demonstrated its critical role in RIPC. The studies have shown that adenosine may elicit cardioprotection via activation of neurogenic pathway. The present review describes the possible role and mechanism of adenosine in mediating RIPC-induced cardioprotection.
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Affiliation(s)
- Puneet Kaur Randhawa
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, 147002, India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, 147002, India.
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5
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Soltysinska E, Bentzen BH, Barthmes M, Hattel H, Thrush AB, Harper ME, Qvortrup K, Larsen FJ, Schiffer TA, Losa-Reyna J, Straubinger J, Kniess A, Thomsen MB, Brüggemann A, Fenske S, Biel M, Ruth P, Wahl-Schott C, Boushel RC, Olesen SP, Lukowski R. KCNMA1 encoded cardiac BK channels afford protection against ischemia-reperfusion injury. PLoS One 2014; 9:e103402. [PMID: 25072914 PMCID: PMC4114839 DOI: 10.1371/journal.pone.0103402] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/01/2014] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial potassium channels have been implicated in myocardial protection mediated through pre-/postconditioning. Compounds that open the Ca2+- and voltage-activated potassium channel of big-conductance (BK) have a pre-conditioning-like effect on survival of cardiomyocytes after ischemia/reperfusion injury. Recently, mitochondrial BK channels (mitoBKs) in cardiomyocytes were implicated as infarct-limiting factors that derive directly from the KCNMA1 gene encoding for canonical BKs usually present at the plasma membrane of cells. However, some studies challenged these cardio-protective roles of mitoBKs. Herein, we present electrophysiological evidence for paxilline- and NS11021-sensitive BK-mediated currents of 190 pS conductance in mitoplasts from wild-type but not BK-/- cardiomyocytes. Transmission electron microscopy of BK-/- ventricular muscles fibres showed normal ultra-structures and matrix dimension, but oxidative phosphorylation capacities at normoxia and upon re-oxygenation after anoxia were significantly attenuated in BK-/- permeabilized cardiomyocytes. In the absence of BK, post-anoxic reactive oxygen species (ROS) production from cardiomyocyte mitochondria was elevated indicating that mitoBK fine-tune the oxidative state at hypoxia and re-oxygenation. Because ROS and the capacity of the myocardium for oxidative metabolism are important determinants of cellular survival, we tested BK-/- hearts for their response in an ex-vivo model of ischemia/reperfusion (I/R) injury. Infarct areas, coronary flow and heart rates were not different between wild-type and BK-/- hearts upon I/R injury in the absence of ischemic pre-conditioning (IP), but differed upon IP. While the area of infarction comprised 28±3% of the area at risk in wild-type, it was increased to 58±5% in BK-/- hearts suggesting that BK mediates the beneficial effects of IP. These findings suggest that cardiac BK channels are important for proper oxidative energy supply of cardiomyocytes at normoxia and upon re-oxygenation after prolonged anoxia and that IP might indeed favor survival of the myocardium upon I/R injury in a BK-dependent mode stemming from both mitochondrial post-anoxic ROS modulation and non-mitochondrial localizations.
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MESH Headings
- Animals
- Cell Hypoxia
- Disease Models, Animal
- Energy Metabolism
- Indoles/pharmacology
- Ischemic Preconditioning
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/genetics
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/metabolism
- Large-Conductance Calcium-Activated Potassium Channels/chemistry
- Large-Conductance Calcium-Activated Potassium Channels/genetics
- Large-Conductance Calcium-Activated Potassium Channels/metabolism
- Membrane Potential, Mitochondrial/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mitochondria, Heart/metabolism
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/metabolism
- Myocardium/metabolism
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Oxidative Phosphorylation/drug effects
- Reactive Oxygen Species/metabolism
- Reperfusion Injury/metabolism
- Reperfusion Injury/pathology
- Tetrazoles/pharmacology
- Thiourea/analogs & derivatives
- Thiourea/pharmacology
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Affiliation(s)
- Ewa Soltysinska
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bo Hjorth Bentzen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Maria Barthmes
- Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität, Munich, Germany; Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
- Nanion Technologies GmbH, Munich, Germany
| | - Helle Hattel
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - A. Brianne Thrush
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Klaus Qvortrup
- Department of Biomedical Sciences, Core Facility for Integrated Microscopy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip J. Larsen
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Tomas A. Schiffer
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Jose Losa-Reyna
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Julia Straubinger
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Angelina Kniess
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Morten Bækgaard Thomsen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Stefanie Fenske
- Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität, Munich, Germany; Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität, Munich, Germany; Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Christian Wahl-Schott
- Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität, Munich, Germany; Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Robert Christopher Boushel
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Søren-Peter Olesen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (SPO); (RL)
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
- * E-mail: (SPO); (RL)
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6
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Pan NC, Bai YF, Yang Y, Hökfelt T, Xu ZQD. Activation of galanin receptor 2 stimulates large conductance Ca2+-dependent K+ (BK) channels through the IP3 pathway in human embryonic kidney (HEK293) cells. Biochem Biophys Res Commun 2014; 446:316-21. [DOI: 10.1016/j.bbrc.2014.02.110] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 01/01/2023]
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7
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Borchert GH, Hlaváčková M, Kolář F. Pharmacological activation of mitochondrial BK(Ca) channels protects isolated cardiomyocytes against simulated reperfusion-induced injury. Exp Biol Med (Maywood) 2013; 238:233-41. [PMID: 23576804 DOI: 10.1177/1535370212474596] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The aim of this study was to find out whether opening of mitochondrial large-conductance Ca(2+)-activated potassium channels (BK(Ca)) protects cardiomyocytes against injury caused by simulated ischemia and reperfusion. This study also aimed to determine whether the protective mechanism involves signaling by reactive oxygen species (ROS) and phosphatidylinositol-3-kinase (PI3K). We used isolated ventricular myocytes, which are believed to contain no functional BK(Ca) channels in the sarcolemma. Cells were isolated from the left ventricles of adult male Wistar rats and subjected to 25-min metabolic inhibition with NaCN and 2-deoxyglucose followed by 30-min re-energization. NS11021 (0.1 μmol/L), a novel BK(Ca) channel opener, or hydrogen peroxide (2 μmol/L) added at re-energization, increased cell survival (the number of rod-shaped cells) and markedly reduced the release of lactate dehydrogenase (LDH). These cytoprotective effects of NS11021 were completely abolished by paxilline, a BK(Ca) inhibitor, or tempol, an antioxidant, but not by wortmannin, an inhibitor of PI3K. NS11021 slightly but significantly increased the fluorescence signal in 2'7'-dichlorodihydrofluorescein diacetate (DCF-DA)-loaded myocytes, indicating an increased ROS formation. The NS11021-induced ROS formation was abolished by paxilline or tempol. NS13558 (0.1 μmol/L), an inactive structural analogue of NS11021, affected neither cell survival/LDH release nor DCF-DA fluorescence. These results suggest that pharmacological activation of mitochondrial BK(Ca) channels effectively protects isolated cardiomyocytes against injury associated with simulated reperfusion. The mechanism for this form of protection requires ROS signaling, but not the activation of the PI3K pathway.
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Affiliation(s)
- Gudrun H Borchert
- Department of Developmental Cardiology, Institute of Physiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
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8
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Chen XQ, Wu SH, Zhou Y, Tang YR. Involvement of K+ channel-dependant pathways in lipoxin A4-induced protective effects on hypoxia/reoxygenation injury of cardiomyocytes. Prostaglandins Leukot Essent Fatty Acids 2013; 88:391-7. [PMID: 23602847 DOI: 10.1016/j.plefa.2013.03.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 02/03/2013] [Accepted: 03/16/2013] [Indexed: 11/24/2022]
Abstract
Studies have shown that lipoxin A4 (LXA4) and activation of LXA4 receptor provided protection against myocardial ischemia/reperfusion injury in animal models. However, the mechanisms by which LXA4 induced protective role on myocardial ischemia/reperfusion injury remains unclear. In the present studies, we investigated the protective effects of LXA4 on H9c2 cardiomyocytes exposed to hypoxia/reoxygenation (H/R) injury and involvement of heme oxygenase-1 (HO-1)- and K(+) channel-dependant pathways in the LXA4 action. H9c2 cardiomyocytes were pretreated with or without LXA4 or HO-1 specific interfering RNA (siRNA) or various blockers and openers of K(+) channels before exposing to H/R injury. The levels of lactate dehydrogenase (LDH) and creatine kinase (CK) in cellular supernatants and necrosis factor-α (TNF-α) in cellular lysates were measured by using ELISA. Expressions of HO-1 mRNA and protein were analyzed by using RT-PCR and Western blot respectively. Pretreatment of the cells undergoing H/R injury with LXA4 significantly reduced the LDH and CK levels induced by H/R injury, and increased the expressions and activity of HO-1. However, the protective effects of LXA4 were completely blocked by transfection of the cells with HO-1 siRNA, and were partially but significantly blocked by pretreatment of the cells with various blockers of K(+) channels. The LXA4-induced expressions of HO-1 in the cells were also inhibited by HO-1 siRNA and various blockers of K(+) channels. The inhibitory effects of LXA4 on enhanced TNF-α levels induced by H/R injury were abolished by transfection of the cells with HO-1 siRNA. In conclusion, the protective role of LXA4 on cardiomyocytes against H/R injury is related to upregulation of HO-1 via reduced production of TNF-α and activation of ATP-sensitive K(+) channels and calcium-sensitive K(+) channel.
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Affiliation(s)
- Xiao-Qing Chen
- Department of Pediatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, People's Republic of China
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9
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Jahania SM, Sengstock D, Vaitkevicius P, Andres A, Ito BR, Gottlieb RA, Mentzer RM. Activation of the homeostatic intracellular repair response during cardiac surgery. J Am Coll Surg 2013; 216:719-26; discussion 726-9. [PMID: 23415552 DOI: 10.1016/j.jamcollsurg.2012.12.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 12/11/2012] [Indexed: 01/24/2023]
Abstract
BACKGROUND The homeostatic intracellular repair response (HIR2) is an endogenous beneficial pathway that eliminates damaged mitochondria and dysfunctional proteins in response to stress. The underlying mechanism is adaptive autophagy. The purpose of this study was to determine whether the HIR2 response is activated in the heart in patients undergoing cardiac surgery and to assess whether it is associated with the duration of ischemic arrest and predicted surgical outcomes. STUDY DESIGN Autophagy was assessed in 19 patients undergoing coronary artery bypass or valve surgery requiring cardiopulmonary bypass. Biopsies of the right atrial appendage obtained before initiation of cardiopulmonary bypass and after weaning from cardiopulmonary bypass were analyzed for autophagy by immunoblotting for LC3, Beclin-1, autophagy 5-12, and p62. Changes in p62, a marker of autophagic flux, were correlated with duration of ischemia and with the mortality/morbidity risk scores obtained from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (version 2.73). RESULTS Heart surgery was associated with a robust increase in autophagic flux indicated by depletion of LC3-I, LC3-II, Beclin-1, and autophagy 5-12; the magnitude of change for each of these factors correlated significantly with changes in the flux marker p62. In addition, changes in p62 correlated directly with cross-clamp time and inversely with the mortality and morbidity risk scores. CONCLUSIONS These findings are consistent with preclinical studies indicating that HIR2 is cardioprotective and reveal that it is activated in patients in response to myocardial ischemic stress. Strategies designed to amplify HIR2 during conditions of cardiac stress might have a therapeutic use and represent an entirely new approach to myocardial protection in patients undergoing heart surgery.
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Affiliation(s)
- Salik M Jahania
- Department of Surgery, Wayne State University School of Medicine, Detroit, MI, USA
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