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Guven C, Taskin E, Aydın Ö, Kaya ST, Sevgiler Y. Diazoxide attenuates DOX-induced cardiotoxicity in cultured rat myocytes. Biotech Histochem 2024; 99:113-124. [PMID: 38439686 DOI: 10.1080/10520295.2024.2324368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024] Open
Abstract
Doxorubicin (DOX)-induced cardiotoxicity is a well known clinical problem, and many investigations have been made of its possible amelioration. We have investigated whether diazoxide (DIA), an agonist at mitochondrial ATP-sensitive potassium channels (mitoKATP), could reverse DOX-induced apoptotic myocardial cell loss, in cultured rat cardiomyocytes. The role of certain proteins in this pathway was also studied. The rat cardiomyocyte cell line (H9c2) was treated with DOX, and also co-treated with DOX and DIA, for 24 h. Distribution of actin filaments, mitochondrial membrane potential, superoxide dismutase (SOD) activity, total oxidant and antioxidant status (TOS and TAS, respectively), and some protein expressions, were assessed. DOX significantly decreased SOD activity, increased ERK1/2 protein levels, and depolarised the mitochondrial membrane, while DIA co-treatment inhibited such changes. DIA co-treatment ameliorated DOX-induced cytoskeletal changes via F-actin distribution and mitoKATP structure. Co-treatment also decreased ERK1/2 and cytochrome c protein levels. Cardiomyocyte loss due to oxidative stress-mediated apoptosis is a key event in DOX-induced cytotoxicity. DIA had protective effects on DOX-induced cardiotoxicity, via mitoKATP integrity, especially with elevated SUR2A levels; but also by a cascade including SOD/AMPK/ERK1/2. Therefore, DIA may be considered a candidate agent for protecting cardiomyocytes against DOX chemotherapy.
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Affiliation(s)
- Celal Guven
- Department of Biophysics, Faculty of Medicine, Adıyaman University, Adıyaman, Turkey
| | - Eylem Taskin
- Department of Physiology, Faculty of Medicine, Adıyaman University, Adıyaman, Turkey
| | - Özgül Aydın
- Department of Biology, Institute of Natural and Applied Sciences, Adıyaman University, Adıyaman, Turkey
| | - Salih Tunç Kaya
- Department of Biology, Faculty of Science and Letters, Düzce University, Düzce, Turkey
| | - Yusuf Sevgiler
- Department of Biology, Faculty of Science and Letters, Adıyaman University, Adıyaman, Turkey
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2
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Maslov LN, Popov SV, Naryzhnaya NV, Mukhomedzyanov AV, Kurbatov BK, Derkachev IA, Boshchenko AA, Prasad NR, Ma H, Zhang Y, Sufianova GZ, Fu F, Pei JM. K ATP channels are regulators of programmed cell death and targets for the creation of novel drugs against ischemia/reperfusion cardiac injury. Fundam Clin Pharmacol 2023; 37:1020-1049. [PMID: 37218378 DOI: 10.1111/fcp.12924] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/29/2023] [Accepted: 05/19/2023] [Indexed: 05/24/2023]
Abstract
BACKGROUND The use of percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is associated with a mortality rate of 5%-7%. It is clear that there is an urgent need to develop new drugs that can effectively prevent cardiac reperfusion injury. ATP-sensitive K+ (KATP ) channel openers (KCOs) can be classified as such drugs. RESULTS KCOs prevent irreversible ischemia and reperfusion injury of the heart. KATP channel opening promotes inhibition of apoptosis, necroptosis, pyroptosis, and stimulation of autophagy. KCOs prevent the development of cardiac adverse remodeling and improve cardiac contractility in reperfusion. KCOs exhibit antiarrhythmic properties and prevent the appearance of the no-reflow phenomenon in animals with coronary artery occlusion and reperfusion. Diabetes mellitus and a cholesterol-enriched diet abolish the cardioprotective effect of KCOs. Nicorandil, a KCO, attenuates major adverse cardiovascular event and the no-reflow phenomenon, reduces infarct size, and decreases the incidence of ventricular arrhythmias in patients with acute myocardial infarction. CONCLUSION The cardioprotective effect of KCOs is mediated by the opening of mitochondrial KATP (mitoKATP ) and sarcolemmal KATP (sarcKATP ) channels, triggered free radicals' production, and kinase activation.
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Affiliation(s)
- Leonid N Maslov
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Sergey V Popov
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Natalia V Naryzhnaya
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Alexandr V Mukhomedzyanov
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Boris K Kurbatov
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Ivan A Derkachev
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Alla A Boshchenko
- Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - N Rajendra Prasad
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, India
| | - Huijie Ma
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Yi Zhang
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Galina Z Sufianova
- Department of Pharmacology, Tyumen State Medical University, Tyumen, Russia
| | - Feng Fu
- Department of Physiology and Pathophysiology, National Key Discipline of Cell Biology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Jian-Ming Pei
- Department of Physiology and Pathophysiology, National Key Discipline of Cell Biology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
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Role of Posttranslational Modifications of Proteins in Cardiovascular Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3137329. [PMID: 35855865 PMCID: PMC9288287 DOI: 10.1155/2022/3137329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/23/2022] [Indexed: 01/03/2023]
Abstract
Cardiovascular disease (CVD) has become a leading cause of mortality and morbidity globally, making it an urgent concern. Although some studies have been performed on CVD, its molecular mechanism remains largely unknown for all types of CVD. However, recent in vivo and in vitro studies have successfully identified the important roles of posttranslational modifications (PTMs) in various diseases, including CVD. Protein modification, also known as PTMs, refers to the chemical modification of specific amino acid residues after protein biosynthesis, which is a key process that can influence the activity or expression level of proteins. Studies on PTMs have contributed directly to improving the therapeutic strategies for CVD. In this review, we examined recent progress on PTMs and highlighted their importance in both physiological and pathological conditions of the cardiovascular system. Overall, the findings of this review contribute to the understanding of PTMs and their potential roles in the treatment of CVD.
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4
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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5
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Pecoraro M, Marzocco S, Popolo A. Diazoxide Needs Mitochondrial Connexin43 to Exert Its Cytoprotective Effect in a Cellular Model of CoCl 2-Induced Hypoxia. Int J Mol Sci 2021; 22:ijms222111599. [PMID: 34769027 PMCID: PMC8583808 DOI: 10.3390/ijms222111599] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 02/07/2023] Open
Abstract
Hypoxia is the leading cause of death in cardiomyocytes. Cells respond to oxygen deprivation by activating cytoprotective programs, such as mitochondrial connexin43 (mCx43) overexpression and the opening of mitochondrial KATP channels, aimed to reduce mitochondrial dysfunction. In this study we used an in vitro model of CoCl2-induced hypoxia to demonstrate that mCx43 and KATP channels cooperate to induce cytoprotection. CoCl2 administration induces apoptosis in H9c2 cells by increasing mitochondrial ROS production, intracellular and mitochondrial calcium overload and by inducing mitochondrial membrane depolarization. Diazoxide, an opener of KATP channels, reduces all these deleterious effects of CoCl2 only in the presence of mCx43. In fact, our results demonstrate that in the presence of radicicol, an inhibitor of Cx43 translocation to mitochondria, the cytoprotective effects of diazoxide disappear. In conclusion, these data confirm that there exists a close functional link between mCx43 and KATP channels.
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6
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Wrzosek A, Augustynek B, Żochowska M, Szewczyk A. Mitochondrial Potassium Channels as Druggable Targets. Biomolecules 2020; 10:E1200. [PMID: 32824877 PMCID: PMC7466137 DOI: 10.3390/biom10081200] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/03/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial potassium channels have been described as important factors in cell pro-life and death phenomena. The activation of mitochondrial potassium channels, such as ATP-regulated or calcium-activated large conductance potassium channels, may have cytoprotective effects in cardiac or neuronal tissue. It has also been shown that inhibition of the mitochondrial Kv1.3 channel may lead to cancer cell death. Hence, in this paper, we examine the concept of the druggability of mitochondrial potassium channels. To what extent are mitochondrial potassium channels an important, novel, and promising drug target in various organs and tissues? The druggability of mitochondrial potassium channels will be discussed within the context of channel molecular identity, the specificity of potassium channel openers and inhibitors, and the unique regulatory properties of mitochondrial potassium channels. Future prospects of the druggability concept of mitochondrial potassium channels will be evaluated in this paper.
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Affiliation(s)
| | | | | | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (B.A.); (M.Ż.)
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7
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Zhou XH, Chai HX, Bai M, Zhang Z. LncRNA-GAS5 regulates PDCD4 expression and mediates myocardial infarction-induced cardiomyocytes apoptosis via targeting MiR-21. Cell Cycle 2020; 19:1363-1377. [PMID: 32308118 DOI: 10.1080/15384101.2020.1750257] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The present study was designed to investigate whether and how lncRNA-GAS5 regulates cardiomyocyte apoptosis in MI. MI rat model was established by the left anterior descending (LAD) coronary artery ligation. MI model was further evaluated by biomarkers detection and TUNEL, HE and Masson staining. The roles of lncRNA-GAS5 on hypoxia/reoxygenation (H/R)-induced cardiomyocytes survival, cell cycle arrest, and apoptosis were examined by MTT and flow cytometry in rat heart-derived H9c2 cells. Western blot was used to determine the effect of GAS5 on the expression of apoptosis-associated proteins and PI3 K/AKT signaling pathway. The direct bindings of GAS5 to miR-21 and miR-21 to PDCD4 were measured by dual-luciferase reporter assay or RNA immunoprecipitation. Decreased expressions of GAS5 and PDCD4 as well as increased miR-21 level were observed in the hearts of MI-modeled rat, accompanying with morphologically myocardial cell injury, as well as collagen deposition and fibrosis, and elevated levels of cTnl, CK, CK-MB and LDH. In the cell model, the knockdown of GAS5 promoted cell survival, prevented cell cycle arrest and inhibited cell apoptosis while the overexpression of GAS5 showed the opposite effects. GAS5 was found to downregulate miR-21 and the effects of GAS5 were attenuated by miR-21 mimics. GAS5 positively regulated PDCD4 expression by functioning as a sponge of miR-21 in H/R model. Moreover, GAS5 stimulated PDCD4 and suppressed PI3 K/AKT signal pathway. LncRNA-GAS5 regulates PDCD4 expression to mediate MI-induced cardiomyocyte apoptosis via targeting miR-21, suggesting that GAS5 could be a therapeutic target for MI.
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Affiliation(s)
- Xing-Hu Zhou
- Department of Cardiology, the First Hospital of Lanzhou University; Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou University , Lanzhou, P.R.China
| | - Hong-Xia Chai
- Department of Obstetrics and Gynecology, The First Hospital of Lanzhou University , Lanzhou, P.R.China
| | - Ming Bai
- Department of Cardiology, the First Hospital of Lanzhou University; Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou University , Lanzhou, P.R.China
| | - Zheng Zhang
- Department of Cardiology, the First Hospital of Lanzhou University; Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou University , Lanzhou, P.R.China
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8
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Singh BL, Chen L, Cai H, Shi H, Wang Y, Yu C, Chen X, Han X, Cai X. Activation of adenosine A2a receptor accelerates and A2a receptor antagonist reduces intermittent hypoxia induced PC12 cell injury via PKC-KATP pathway. Brain Res Bull 2019; 150:118-126. [PMID: 31129168 DOI: 10.1016/j.brainresbull.2019.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/19/2019] [Accepted: 05/21/2019] [Indexed: 02/07/2023]
Abstract
Obstructive sleep apnea hypopnea syndrome (OSAHS) is associated with multiple system diseases. Neurocognitive dysfunction resulting from central nervous system complications has been reported, especially in children with OSAHS. Chronic intermittent hypoxia is accepted to be the major pathophysiological mechanism of OSAHS. Adenosine plays an important role in cellular function via interactions with its receptors. A2a receptor has been recognized as a factor involved in neuroprotection. However, the role of adenosine A2a receptor in intermittent hypoxia induced cellular injury is not completely understood. In this study, we aim to investigate the underlying mechanisms of A2a receptor mediated cellular damage caused by intermittent hypoxia in PC12 cells. We found that activated A2a receptor by CGS21680 decreased cellular viability, increased PKC as well as ATP-sensitive potassium channel (KATP) subunits expression Kir6.2 and SUR1. Inhibition of A2a receptor by SCH58261 increased cellular viability, suppressed PKC and SUR1 expression level, ultimately showing a protective role in PC12 cells. Moreover, we observed that CHE, which is an antagonist of PKC, downregulated Kir6.2 and SUR1 expression and increased cellular viability. Additionally, we found that A2a receptor activation induced cell injury was associated with increased Cleaved-Caspase 3 expression, which can be decreased by inhibition of A2a receptor or PKC. In conclusion, our findings indicate that A2a receptor induced KATP expression by PKC activation and plays a role in accelerating PC12 cells injury induced by intermittent hypoxia exposure via A2a-PKC-KATP signal pathway mediated apoptosis.
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Affiliation(s)
- Brett Lyndall Singh
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Liya Chen
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Huilin Cai
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Hua Shi
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Yueyuan Wang
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Chenyi Yu
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China
| | - Xu Chen
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China
| | - Xinru Han
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xiaohong Cai
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, Zhejiang, 325027, PR China; The Second School Of Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, PR China.
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9
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Duan P, Wang J, Li Y, Wei S, Su F, Zhang S, Duan Y, Wang L, Zhu Q. Opening of mitoKATP improves cardiac function and inhibits apoptosis via the AKT-Foxo1 signaling pathway in diabetic cardiomyopathy. Int J Mol Med 2018; 42:2709-2719. [PMID: 30132505 PMCID: PMC6192784 DOI: 10.3892/ijmm.2018.3832] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 08/16/2018] [Indexed: 12/21/2022] Open
Abstract
Decreasing phosphorylation of AKT-Foxo1 is closely associated with the onset of insulin resistance and apoptosis during diabetic cardiomyopathy (DCM). Opening of mitochondrial ATP-sensitive potassium channels (mitoKATP) increases the expression of p-AKT in the process of reperfusion injury. It was therefore hypothesized that opening of mitoKATP may regulate the AKT-Foxo1 signaling pathway and improve cardiac function in DCM. In the present study, opening of mitoKATP by diazoxide (DZX) was found to improve cardiac function and attenuate cardiomyocyte apoptosis in db/db mice. DZX also significantly increased the expression of p-AKT and p-Foxo1. Similarly, DZX decreased the expression of the heart failure marker NT-proBNP, increased mitochondrial membrane potential, inhibited apoptosis, and increased the expression of p-AKT and p-Foxo1 when mimicking insulin resistance in cultured cardiomyocytes. Moreover, the protective effects of DZX were completely blocked by the specific AKT inhibitor MK-2206. These data suggest that the regulation of the AKT-Foxo1 signaling pathway by mitoKATP plays an important role in improving cardiac function and inhibiting apoptosis in DCM, and may therefore be a new potential therapeutic target for DCM.
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Affiliation(s)
- Peng Duan
- Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Jinxin Wang
- Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Yang Li
- Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Shiqiang Wei
- Department of Cardiology, Chinese PLA No. 371 Hospital, Xinxiang, Henan 453000, P.R. China
| | - Feng Su
- Department of Medical Administration, Chinese PLA No. 371 Hospital, Xinxiang, Henan 453000, P.R. China
| | - Sanlin Zhang
- Department of Cardiology, Chinese PLA No. 371 Hospital, Xinxiang, Henan 453000, P.R. China
| | - Yuhui Duan
- Department of Cardiology, Chinese PLA No. 371 Hospital, Xinxiang, Henan 453000, P.R. China
| | - Lin Wang
- Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Qinglei Zhu
- Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, P.R. China
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10
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Pecoraro M, Ciccarelli M, Fiordelisi A, Iaccarino G, Pinto A, Popolo A. Diazoxide Improves Mitochondrial Connexin 43 Expression in a Mouse Model of Doxorubicin-Induced Cardiotoxicity. Int J Mol Sci 2018. [PMID: 29518932 PMCID: PMC5877618 DOI: 10.3390/ijms19030757] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Doxorubicin (DOXO) administration induces alterations in Connexin 43 (Cx43) expression and localization, thus, inducing alterations in chemical and electrical signal transmission between cardiomyocytes and in intracellular calcium homeostasis even evident after a single administration. This study was designed to evaluate if Diazoxide (DZX), a specific opener of mitochondrial KATP channels widely used for its cardioprotective effects, can fight DOXO-induced cardiotoxicity in a short-time mouse model. DZX (20 mg/kg i.p.) was administered 30 min before DOXO (10 mg/kg i.p.) in C57BL/6j female mice for 1–3 or seven days once every other day. A recovery of cardiac parameters, evaluated by Echocardiography, were observed in DZX+DOXO co-treated mice. Western blot analysis performed on heart lysates showed an increase in sarco/endoplasmic reticulum Ca2+-ATPase (SERCAII) and a reduction in phospholamban (PLB) amounts in DZX+DOXO co-treated mice. A contemporary recovery of intracellular Ca2+-signal, detected spectrofluorometrically by means of FURA-2AM, was observed in these mice. Cx43 expression and localization, analyzed by Western blot and confirmed by immunofluorescence analysis, showed that DZX co-treatement increases Cx43 amount both on sarcoplasmic membrane and on mitochondria. In conclusion, our data demonstrate that, in a short-time mouse model of DOXO-induced cardiotoxicity, DZX exerts its cardioprotective effects also by enhancing the amount Cx43.
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Affiliation(s)
- Michela Pecoraro
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy.
| | - Michele Ciccarelli
- Department of Medicine and Surgery, University of Salerno, 84084 Baronissi, Italy.
| | - Antonella Fiordelisi
- Department of Advanced Biomedical Sciences, Federico II University, 80138 Naples, Italy.
| | - Guido Iaccarino
- Department of Medicine and Surgery, University of Salerno, 84084 Baronissi, Italy.
| | - Aldo Pinto
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy.
| | - Ada Popolo
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy.
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11
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Wu YN, Shen KZ, Johnson SW. Differential actions of AMP kinase on ATP-sensitive K + currents in ventral tegmental area and substantia nigra zona compacta neurons. Eur J Neurosci 2017; 46:2746-2753. [PMID: 29057540 DOI: 10.1111/ejn.13756] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/22/2017] [Accepted: 10/16/2017] [Indexed: 12/21/2022]
Abstract
ATP-sensitive K+ (K-ATP) channels play significant roles in regulating the excitability of dopamine neurons in the substantia nigra zona compacta (SNC). We showed previously that K-ATP channel function is up-regulated by AMP-activated protein kinase (AMPK). This study extended these studies to the neurons adjacent to the SNC in the ventral tegmental area (VTA). Using patch pipettes to record whole-cell currents in slices of rat midbrain, we found that the AMPK activator A769662 increased the amplitude of currents evoked by the K-ATP channel opener diazoxide in presumed dopamine-containing VTA neurons. However, current evoked by diazoxide with A769662 was significantly smaller in VTA neurons compared to SNC neurons. Moreover, a significantly lower proportion of VTA neurons responded to diazoxide with outward current. However, A769662 was able to increase the incidence of diazoxide-responsive neurons in the VTA. In contrast, A769662 did not potentiate diazoxide-evoked currents in presumed non-dopamine VTA neurons. These results show that AMPK activation augments K-ATP currents in presumed dopamine neurons in the VTA and SNC, although diazoxide-evoked currents remain less robust in the VTA. We conclude that K-ATP channels may play important physiological roles in VTA and SNC dopamine neurons.
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Affiliation(s)
- Yan-Na Wu
- Department of Neurology, Oregon Health & Science University, Portland, OR, USA
| | - Ke-Zhong Shen
- Department of Neurology, Oregon Health & Science University, Portland, OR, USA
| | - Steven W Johnson
- Department of Neurology, Oregon Health & Science University, Portland, OR, USA.,Veterans Affairs Portland Health Care System, Portland, OR, 97239, USA
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12
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Deryagin OG, Gavrilova SA, Gainutdinov KL, Golubeva AV, Andrianov VV, Yafarova GG, Buravkov SV, Koshelev VB. Molecular Bases of Brain Preconditioning. Front Neurosci 2017; 11:427. [PMID: 28790886 PMCID: PMC5524930 DOI: 10.3389/fnins.2017.00427] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/11/2017] [Indexed: 12/20/2022] Open
Abstract
Preconditioning of the brain induces tolerance to the damaging effects of ischemia and prevents cell death in ischemic penumbra. The development of this phenomenon is mediated by mitochondrial adenosine triphosphate-sensitive potassium (KATP+) channels and nitric oxide signaling (NO). The aim of this study was to investigate the dynamics of molecular changes in mitochondria after ischemic preconditioning (IP) and the effect of pharmacological preconditioning (PhP) with the KATP+-channels opener diazoxide on NO levels after ischemic stroke in rats. Immunofluorescence-histochemistry and laser-confocal microscopy were applied to evaluate the cortical expression of electron transport chain enzymes, mitochondrial KATP+-channels, neuronal and inducible NO-synthases, as well as the dynamics of nitrosylation and nitration of proteins in rats during the early and delayed phases of IP. NO cerebral content was studied with electron paramagnetic resonance (EPR) spectroscopy using spin trapping. We found that 24 h after IP in rats, there is a two-fold decrease in expression of mitochondrial KATP+-channels (p = 0.012) in nervous tissue, a comparable increase in expression of cytochrome c oxidase (p = 0.008), and a decrease in intensity of protein S-nitrosylation and nitration (p = 0.0004 and p = 0.001, respectively). PhP led to a 56% reduction of free NO concentration 72 h after ischemic stroke simulation (p = 0.002). We attribute this result to the restructuring of tissue energy metabolism, namely the provision of increased catalytic sites to mitochondria and the increased elimination of NO, which prevents a decrease in cell sensitivity to oxygen during subsequent periods of severe ischemia.
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Affiliation(s)
- Oleg G Deryagin
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Svetlana A Gavrilova
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Khalil L Gainutdinov
- Laboratory of Neurorehabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal UniversityKazan, Russia.,Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of SciencesKazan, Russia
| | - Anna V Golubeva
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Vyatcheslav V Andrianov
- Laboratory of Neurorehabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal UniversityKazan, Russia.,Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of SciencesKazan, Russia
| | - Guzel G Yafarova
- Laboratory of Neurorehabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal UniversityKazan, Russia.,Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of SciencesKazan, Russia
| | - Sergey V Buravkov
- Research Laboratory of Cellular Structure and Tissue Imaging Analysis, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Vladimir B Koshelev
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
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13
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Kim AY, Jeong KH, Lee JH, Kang Y, Lee SH, Baik EJ. Glutamate dehydrogenase as a neuroprotective target against brain ischemia and reperfusion. Neuroscience 2016; 340:487-500. [PMID: 27845178 DOI: 10.1016/j.neuroscience.2016.11.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/02/2016] [Accepted: 11/06/2016] [Indexed: 01/13/2023]
Abstract
Deregulation of glutamate homeostasis is associated with degenerative neurological disorders. Glutamate dehydrogenase (GDH) is important for glutamate metabolism and plays a central role in expanding the pool of tricarboxylic acid (TCA) cycle intermediate alpha-ketoglutarate (α-KG), which improves overall bioenergetics. Under high energy demand, maintenance of ATP production results in functionally active mitochondria. Here, we tested whether the modulation of GDH activity can rescue ischemia/reperfusion-induced neuronal death in an in vivo mouse model of middle artery occlusion and an in vitro oxygen/glucose depletion model. Iodoacetate, an inhibitor of glycolysis, was also used in a model of energy failure, remarkably depleting ATP and α-KG. To stimulate GDH activity, the GDH activator 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid and potential activator beta-lapachone were used. The GDH activators restored α-KG and ATP levels in the injury models and provided potent neuroprotection. We also found that beta-lapachone increased glutamate utilization, accompanied by a reduction in extracellular glutamate. Thus, our hypothesis that mitochondrial GDH activators increase α-KG production as an alternative energy source for use in the TCA cycle under energy-depleted conditions was confirmed. Our results suggest that increasing GDH-mediated glutamate oxidation represents a new therapeutic intervention for neurodegenerative disorders, including stoke.
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Affiliation(s)
- A Young Kim
- Department of Physiology, Ajou University School of Medicine, Suwon 16499, Republic of Korea; Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Kyeong-Hoon Jeong
- Gachon University of Medicine and Science, Incheon 406-840, Republic of Korea
| | - Jae Ho Lee
- Department of Biochemistry, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Yup Kang
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Soo Hwan Lee
- Department of Physiology, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Eun Joo Baik
- Department of Physiology, Ajou University School of Medicine, Suwon 16499, Republic of Korea; Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea.
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14
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Tricarico D, Selvaggi M, Passantino G, De Palo P, Dario C, Centoducati P, Tateo A, Curci A, Maqoud F, Mele A, Camerino GM, Liantonio A, Imbrici P, Zizzo N. ATP Sensitive Potassium Channels in the Skeletal Muscle Function: Involvement of the KCNJ11(Kir6.2) Gene in the Determination of Mechanical Warner Bratzer Shear Force. Front Physiol 2016; 7:167. [PMID: 27242541 PMCID: PMC4862255 DOI: 10.3389/fphys.2016.00167] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/25/2016] [Indexed: 12/25/2022] Open
Abstract
The ATP-sensitive K+-channels (KATP) are distributed in the tissues coupling metabolism with K+ ions efflux. KATP subunits are encoded by KCNJ8 (Kir6.1), KCNJ11 (Kir6.2), ABCC8 (SUR1), and ABCC9 (SUR2) genes, alternative RNA splicing give rise to SUR variants that confer distinct physiological properties on the channel. An high expression/activity of the sarco-KATP channel is observed in various rat fast-twitch muscles, characterized by elevated muscle strength, while a low expression/activity is observed in the slow-twitch muscles characterized by reduced strength and frailty. Down-regulation of the KATP subunits of fast-twitch fibers is found in conditions characterized by weakness and frailty. KCNJ11 gene knockout mice have reduced glycogen, lean phenotype, lower body fat, and weakness. KATP channel is also a sensor of muscle atrophy. The KCNJ11 gene is located on BTA15, close to a QTL for meat tenderness, it has also a role in glycogen storage, a key mechanism of the postmortem transformation of muscle into meat. The role of KCNJ11 gene in muscle function may underlie an effect of KCNJ11 genotypes on meat tenderness, as recently reported. The fiber phenotype and genotype are important in livestock production science. Quantitative traits including meat production and quality are influenced both by environment and genes. Molecular markers can play an important role in the genetic improvement of animals through breeding strategies. Many factors influence the muscle Warner-Bratzler shear force including breed, age, feeding, the biochemical, and functional parameters. The role of KCNJ11gene and related genes on muscle tenderness will be discussed in the present review.
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Affiliation(s)
- Domenico Tricarico
- Department of Pharmacy-Drug Science, University of Bari Aldo Moro Bari, Italy
| | - Maria Selvaggi
- Section of Veterinary Science and Animal Production, Department of Emergency and Organ Transplantation (DETO), University of Bari Aldo Moro Valenzano, Italy
| | | | - Pasquale De Palo
- Department of Veterinary Medicine, University of Bari Aldo Moro Bari, Italy
| | - Cataldo Dario
- Section of Veterinary Science and Animal Production, Department of Emergency and Organ Transplantation (DETO), University of Bari Aldo Moro Valenzano, Italy
| | | | - Alessandra Tateo
- Department of Veterinary Medicine, University of Bari Aldo Moro Bari, Italy
| | - Angela Curci
- Department of Pharmacy-Drug Science, University of Bari Aldo Moro Bari, Italy
| | - Fatima Maqoud
- Department of Pharmacy-Drug Science, University of Bari Aldo MoroBari, Italy; Faculty of Science, Chouaib Doukkali UniversityEl Jadida, Morocco
| | - Antonietta Mele
- Department of Pharmacy-Drug Science, University of Bari Aldo Moro Bari, Italy
| | - Giulia M Camerino
- Department of Pharmacy-Drug Science, University of Bari Aldo Moro Bari, Italy
| | - Antonella Liantonio
- Department of Pharmacy-Drug Science, University of Bari Aldo Moro Bari, Italy
| | - Paola Imbrici
- Department of Pharmacy-Drug Science, University of Bari Aldo Moro Bari, Italy
| | - Nicola Zizzo
- Department of Veterinary Medicine, University of Bari Aldo Moro Bari, Italy
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15
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Laskowski M, Augustynek B, Kulawiak B, Koprowski P, Bednarczyk P, Jarmuszkiewicz W, Szewczyk A. What do we not know about mitochondrial potassium channels? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1247-1257. [PMID: 26951942 DOI: 10.1016/j.bbabio.2016.03.007] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 01/14/2023]
Abstract
In this review, we summarize our knowledge about mitochondrial potassium channels, with a special focus on unanswered questions in this field. The following potassium channels have been well described in the inner mitochondrial membrane: ATP-regulated potassium channel, Ca(2+)-activated potassium channel, the voltage-gated Kv1.3 potassium channel, and the two-pore domain TASK-3 potassium channel. The primary functional roles of these channels include regulation of mitochondrial respiration and the alteration of membrane potential. Additionally, they modulate the mitochondrial matrix volume and the synthesis of reactive oxygen species by mitochondria. Mitochondrial potassium channels are believed to contribute to cytoprotection and cell death. In this paper, we discuss fundamental issues concerning mitochondrial potassium channels: their molecular identity, channel pharmacology and functional properties. Attention will be given to the current problems present in our understanding of the nature of mitochondrial potassium channels. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Michał Laskowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Bartłomiej Augustynek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Piotr Koprowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Piotr Bednarczyk
- Department of Biophysics, Warsaw University of Life Sciences - SGGW, 159 Nowoursynowska St., 02-776 Warsaw, Poland
| | - Wieslawa Jarmuszkiewicz
- Laboratory of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland.
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16
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Abstract
KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease.
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Affiliation(s)
- Monique N Foster
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| | - William A Coetzee
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
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17
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Barreto-Torres G, Hernandez JS, Jang S, Rodríguez-Muñoz AR, Torres-Ramos CA, Basnakian AG, Javadov S. The beneficial effects of AMP kinase activation against oxidative stress are associated with prevention of PPARα-cyclophilin D interaction in cardiomyocytes. Am J Physiol Heart Circ Physiol 2015; 308:H749-58. [PMID: 25617357 DOI: 10.1152/ajpheart.00414.2014] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 01/16/2015] [Indexed: 12/21/2022]
Abstract
AMP kinase (AMPK) plays an important role in the regulation of energy metabolism in cardiac cells. Furthermore, activation of AMPK protects the heart from myocardial infarction and heart failure. The present study examines whether or not AMPK affects the peroxisome proliferator-activated receptor-α (PPARα)/mitochondria pathway in response to acute oxidative stress in cultured cardiomyocytes. Cultured H9c2 rat embryonic cardioblasts were exposed to H2O2-induced acute oxidative stress in the presence or absence of metformin, compound C (AMPK inhibitor), GW6471 (PPARα inhibitor), or A-769662 (AMPK activator). Results showed that AMPK activation by metformin reverted oxidative stress-induced inactivation of AMPK and prevented oxidative stress-induced cell death. In addition, metformin attenuated reactive oxygen species generation and depolarization of the inner mitochondrial membrane. The antioxidative effects of metformin were associated with the prevention of mitochondrial DNA damage in cardiomyocytes. Coimmunoprecipitation studies revealed that metformin abolished oxidative stress-induced physical interactions between PPARα and cyclophilin D (CypD), and the abolishment of these interactions was associated with inhibition of permeability transition pore formation. The beneficial effects of metformin were not due to acetylation or phosphorylation of PPARα in response to oxidative stress. In conclusion, this study demonstrates that the protective effects of metformin-induced AMPK activation against oxidative stress converge on mitochondria and are mediated, at least in part, through the dissociation of PPARα-CypD interactions, independent of phosphorylation and acetylation of PPARα and CypD.
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Affiliation(s)
- Giselle Barreto-Torres
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; and
| | - Jessica Soto Hernandez
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; and
| | - Sehwan Jang
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; and
| | - Adlín R Rodríguez-Muñoz
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; and
| | - Carlos A Torres-Ramos
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; and
| | - Alexei G Basnakian
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Sabzali Javadov
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; and
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18
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Brennan S, Jackson R, Patel M, Sims MW, Hudman D, Norman RI, Lodwick D, Rainbow RD. Early opening of sarcolemmal ATP-sensitive potassium channels is not a key step in PKC-mediated cardioprotection. J Mol Cell Cardiol 2014; 79:42-53. [PMID: 25450614 DOI: 10.1016/j.yjmcc.2014.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 09/29/2014] [Accepted: 10/20/2014] [Indexed: 11/29/2022]
Abstract
ATP-sensitive potassium (KATP) channels are abundantly expressed in the myocardium. Although a definitive role for the channel remains elusive they have been implicated in the phenomenon of cardioprotection, but the precise mechanism is unclear. We set out to test the hypothesis that the channel protects by opening early during ischemia to shorten action potential duration and reduce electrical excitability thus sparing intracellular ATP. This could reduce reperfusion injury by improving calcium homeostasis. Using a combination of contractile function analysis, calcium fluorescence imaging and patch clamp electrophysiology in cardiomyocytes isolated from adult male Wistar rats, we demonstrated that the opening of sarcolemmal KATP channels was markedly delayed after cardioprotective treatments: ischemic preconditioning, adenosine and PMA. This was due to the preservation of intracellular ATP for longer during simulated ischemia therefore maintaining sarcolemmal KATP channels in the closed state for longer. As the simulated ischemia progressed, KATP channels opened to cause contractile, calcium transient and action potential failure; however there was no indication of any channel activity early during simulated ischemia to impart an energy sparing hyperpolarization or action potential shortening. We present compelling evidence to demonstrate that an early opening of sarcolemmal KATP channels during simulated ischemia is not part of the protective mechanism imparted by ischemic preconditioning or other PKC-dependent cardioprotective stimuli. On the contrary, channel opening was actually delayed. We conclude that sarcolemmal KATP channel opening is a consequence of ATP depletion, not a primary mechanism of ATP preservation in these cells.
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Affiliation(s)
- Sean Brennan
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK
| | - Robert Jackson
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK
| | - Manish Patel
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK
| | - Mark W Sims
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK
| | - Diane Hudman
- Department of Medical and Social Care Education, Maurice Shock Medical Sciences Building, University of Leicester, Leicester, LE1 9HN, UK
| | - Robert I Norman
- Department of Medical and Social Care Education, Maurice Shock Medical Sciences Building, University of Leicester, Leicester, LE1 9HN, UK
| | - David Lodwick
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK
| | - Richard D Rainbow
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK.
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19
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Dual response of the KATP channels to staurosporine: a novel role of SUR2B, SUR1 and Kir6.2 subunits in the regulation of the atrophy in different skeletal muscle phenotypes. Biochem Pharmacol 2014; 91:266-75. [PMID: 24998494 DOI: 10.1016/j.bcp.2014.06.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/26/2014] [Accepted: 06/26/2014] [Indexed: 11/23/2022]
Abstract
We investigated on the role of the genes encoding for the ATP-sensitive K(+)-channel (KATP) subunits (SUR1-2A/B, Kir6.2) in the atrophy induced "in vitro" by staurosporine (STS) in different skeletal muscle phenotypes of mouse. Patch-clamp and gene expression experiments showed that the expression/activity of the sarcolemma KATP channel subunits was higher in the fast-twitch than in the slow-twitch fibers. After 1 to 3h of incubation time, the STS (2.14×10(-6)M) treatment enhanced the expression/activity of the SUR2B, SUR1 and Kir6.2 subunit genes, but not SUR2A, in the slow-twitch muscle fibers, induced the caspase-3-9, Atrogin-1 and Murf-1 gene expression without affecting protein content. After 3 to 6h, the STS-related atrophy markedly down-regulated the SUR2B, SUR1 and Kir6.2 genes reducing the KATP currents and reduced the protein content/muscle weight ratio of the slow-twitch muscle by -36.4±6% (p<0.05). After 6 to 24h, no additional changes of the SUR1-2B and Kir6.2 gene expression and muscle protein were observed. In the fast-twitch muscles, STS mildly affected the atrophic genes and protein content, but potentiated the KATP currents down-regulating the Bnip-3 gene. Diazoxide (250-500×10(-6)M), a SUR1-2B/Kir6.2 channel opener, prevented the protein loss induced by STS in the slow-twitch muscle after 6h showing an EC50 of 1.35×10(-7)M and Emax of 75%, down-regulated the caspase-9 gene and enhanced the KATP currents. The enhanced expression/activity of the SUR2B, SUR1 and Kir6.2 genes are cytoprotective against STS-induced atrophy in the slow-twitch muscle; their reduced expression/activity is associated with proteolysis and atrophy in skeletal muscle.
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20
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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21
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Nazarewicz RR, Dikalova AE, Bikineyeva A, Dikalov SI. Nox2 as a potential target of mitochondrial superoxide and its role in endothelial oxidative stress. Am J Physiol Heart Circ Physiol 2013; 305:H1131-40. [PMID: 23955717 DOI: 10.1152/ajpheart.00063.2013] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Superoxide (O2(·-)) production by the NADPH oxidases is implicated in the pathogenesis of many cardiovascular diseases, including hypertension. We have previously shown that activation of NADPH oxidases increases mitochondrial O2(·-) which is inhibited by the ATP-sensitive K(+) channel (mitoKATP) inhibitor 5-hydroxydecanoic acid and that scavenging of mitochondrial or cytoplasmic O2(·-) inhibits hypertension. We hypothesized that mitoKATP-mediated mitochondrial O2(·-) potentiates cytoplasmic O2(·-) by stimulation of NADPH oxidases. In this work we studied Nox isoforms as a potential target of mitochondrial O2(·-). We tested contribution of reverse electron transfer (RET) from complex II to complex I in mitochondrial O2(·-) production and NADPH oxidase activation in human aortic endothelial cells. Activation of mitoKATP with low dose of diazoxide (100 nM) decreased mitochondrial membrane potential (tetramethylrhodamine methyl ester probe) and increased production of mitochondrial and cytoplasmic O2(·-) measured by site-specific probes and mitoSOX. Inhibition of RET with complex II inhibitor (malonate) or complex I inhibitor (rotenone) attenuated the production of mitochondrial and cytoplasmic O2(·-). Supplementation with a mitochondria-targeted SOD mimetic (mitoTEMPO) or a mitochondria-targeted glutathione peroxidase mimetic (mitoEbselen) inhibited production of mitochondrial and cytoplasmic O2(·-). Inhibition of Nox2 (gp91ds) or Nox2 depletion with small interfering RNA but not Nox1, Nox4, or Nox5 abolished diazoxide-induced O2(·-) production in the cytoplasm. Treatment of angiotensin II-infused mice with RET inhibitor dihydroethidium (malate) significantly reduced blood pressure. Our study suggests that mitoKATP-mediated mitochondrial O2(·-) stimulates cytoplasmic Nox2, contributing to the development of endothelial oxidative stress and hypertension.
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Affiliation(s)
- Rafal R Nazarewicz
- Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
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22
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Tamari F, Chen FW, Li C, Chaudhari J, Ioannou YA. PKC activation in Niemann pick C1 cells restores subcellular cholesterol transport. PLoS One 2013; 8:e74169. [PMID: 23977398 PMCID: PMC3744505 DOI: 10.1371/journal.pone.0074169] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/29/2013] [Indexed: 02/07/2023] Open
Abstract
Activation of protein kinase C (PKC) has previously been shown to ameliorate the cholesterol transport defect in Niemann Pick Type C1 (NPC1) cells, presumably by increasing the soluble levels of one of its substrates, vimentin. This activity would then restore the vimentin cycle in these cells and allow vimentin-dependent retrograde transport to proceed. Here, we further investigate the effects of PKC activation in NPC1 cells by evaluating different isoforms for their ability to solubilize vimentin and correct the NPC1 cholesterol storage phenotype. We also examine the effects of PKC activators, including free fatty acids and the PKC-specific activator diazoxide, on the NPC1 disease phenotype. Our results indicate that PKC isoforms α, βII, and ε have the greatest effects on vimentin solubilization. Furthermore, expression or activation of PKCε in NPC1 cells dramatically reduces the amount of stored cholesterol and restores cholesterol transport out of endocytic vesicles. These results provide further support for the contribution of PKCs in NPC1 disease pathogenesis and suggest that PKCs may be targeted in future efforts to develop therapeutics for NPC1 disease.
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Affiliation(s)
- Farshad Tamari
- Department of Genetics and Genomic Sciences, the Mount Sinai School of Medicine, New York, New York, United States of America
- Department of Biological Sciences, Kingsborough Community College, Brooklyn, New York, United States of America
| | - Fannie W. Chen
- Department of Genetics and Genomic Sciences, the Mount Sinai School of Medicine, New York, New York, United States of America
| | - Chunlei Li
- Department of Genetics and Genomic Sciences, the Mount Sinai School of Medicine, New York, New York, United States of America
| | - Jagrutiben Chaudhari
- Department of Genetics and Genomic Sciences, the Mount Sinai School of Medicine, New York, New York, United States of America
| | - Yiannis A. Ioannou
- Department of Genetics and Genomic Sciences, the Mount Sinai School of Medicine, New York, New York, United States of America
- * E-mail:
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23
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Coetzee WA. Multiplicity of effectors of the cardioprotective agent, diazoxide. Pharmacol Ther 2013; 140:167-75. [PMID: 23792087 DOI: 10.1016/j.pharmthera.2013.06.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 02/02/2023]
Abstract
Diazoxide has been identified over the past 50years to have a number of physiological effects, including lowering the blood pressure and rectifying hypoglycemia. Today it is used clinically to treat these conditions. More recently, another important mode of action emerged: diazoxide has powerful protective properties against cardiac ischemia. The heart has intrinsic protective mechanisms against ischemia injury; one of which is ischemic preconditioning. Diazoxide mimics ischemic preconditioning. The purpose of this treatise is to review the literature in an attempt to identify the many effectors of diazoxide and discuss how they may contribute to diazoxide's cardioprotective properties. Particular emphasis is placed on the concentration ranges in which diazoxide affects its different targets and how this compares with the concentrations commonly used to study cardioprotection. It is concluded that diazoxide may have several potential effectors that may potentially contribute to cardioprotection, including KATP channels in the pancreas, smooth muscle, endothelium, neurons and the mitochondrial inner membrane. Diazoxide may also affect other ion channels and ATPases and may directly regulate mitochondrial energetics. It is possible that the success of diazoxide lies in this promiscuity and that the compound acts to rebalance multiple physiological processes during cardiac ischemia.
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Affiliation(s)
- William A Coetzee
- Department of Pediatrics, NYU School of Medicine, New York, NY 10016, United States; Department of Physiology & Neuroscience, NYU School of Medicine, New York, NY 10016, United States; Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, United States.
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Liu Q, Yao JY, Qian C, Chen R, Li XY, Liu SW, Sun BG, Song LS, Hong J. Effects of propofol on ischemia-induced ventricular arrhythmias and mitochondrial ATP-sensitive potassium channels. Acta Pharmacol Sin 2012; 33:1495-501. [PMID: 22983391 DOI: 10.1038/aps.2012.86] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
AIM To investigate the potential of propofol in suppressing ventricular arrhythmias and to examine whether mitochondrial ATP-sensitive potassium channels are involved. METHODS Male Sprague-Dawley rats were pretreated with intravenous infusion of propofol (Prop), a selective mitochondrial KATP channel inhibitor 5-hydroxydecanoate (5-HD), propofol plus 5-HD (Prop+5-HD), a potent mitochondrial K(ATP) channel opener diazoxide (DZ) or NS, respectively. The dosage of each drug was 10 mg/kg. The animals then underwent a 30 min-ligation of the left anterior descending artery. The severity of arrhythmias, the incidence of ventricular fibrillation (VF), and the time of the first run of ventricular arrhythmias were documented using an arrhythmia scoring system. Mitochondrial membrane potential (ΔΨm) was measured in freshly isolated rat cardiomyocytes with a fluorescence microscope. RESULTS The arrhythmia scores in the Prop and DZ group were 2.6(0-5) and 2.4(0-5), respectively, which were significantly lower than that in the control group [4.9(2-8)]. VF was not observed in both Prop and DZ groups. The first run of ventricular arrhythmias was significantly postponed in the Prop group (10.5±2.2 vs 7.3±1.9 min). Bracketing of propofol with 5-HD eliminated the anti-arrhythmic effect of propofol. In isolated rat cardiomyocytes, propofol (50 μmol/L) significantly decreased ΔΨm, but when propofol was co-administered with 5-HD, the effect on ΔΨm was reversed. CONCLUSION Propofol preconditioning suppresses ischemia-induced ventricular arrhythmias in the rat heart, which are proposed to be caused by opening of mitochondrial K(ATP) channels.
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Sarveswaran S, Thamilselvan V, Brodie C, Ghosh J. Inhibition of 5-lipoxygenase triggers apoptosis in prostate cancer cells via down-regulation of protein kinase C-epsilon. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:2108-17. [PMID: 21824498 DOI: 10.1016/j.bbamcr.2011.07.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 07/22/2011] [Accepted: 07/25/2011] [Indexed: 12/31/2022]
Abstract
Previous studies have shown that human prostate cancer cells constitutively generate 5-lipoxygenase (5-LOX) metabolites from arachidonic acid, and inhibition of 5-LOX blocks production of 5-LOX metabolites and triggers apoptosis in prostate cancer cells. This apoptosis is prevented by exogenous metabolites of 5-LOX, suggesting an essential role of 5-LOX metabolites in the survival of prostate cancer cells. However, downstream signaling mechanisms which mediate the survival-promoting effects of 5-LOX metabolites in prostate cancer cells are still unknown. Recently, we reported that MK591, a specific inhibitor of 5-LOX activity, induces apoptosis in prostate cancer cells without inhibition of Akt, or ERK, two well-characterized regulators of pro-survival mechanisms, suggesting the existence of an Akt and ERK-independent survival mechanism in prostate cancer cells regulated by 5-LOX. Here, we report that 5-LOX inhibition-induced apoptosis in prostate cancer cells occurs via rapid inactivation of protein kinase C-epsilon (PKCε), and that exogenous 5-LOX metabolites prevent both 5-LOX inhibition-induced down-regulation of PKCε and induction of apoptosis. Interestingly, pre-treatment of prostate cancer cells with diazoxide (a chemical activator of PKCε), or KAE1-1 (a cell-permeable, octa-peptide specific activator of PKCε) prevents 5-LOX inhibition-induced apoptosis, which indicates that inhibition of 5-LOX triggers apoptosis in prostate cancer cells via down-regulation of PKCε. Altogether, these findings suggest that metabolism of arachidonic acid by 5-LOX activity promotes survival of prostate cancer cells via signaling through PKCε, a pro-survival serine/threonine kinase.
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Fajardo G, Zhao M, Berry G, Wong LJ, Mochly-Rosen D, Bernstein D. β2-adrenergic receptors mediate cardioprotection through crosstalk with mitochondrial cell death pathways. J Mol Cell Cardiol 2011; 51:781-9. [PMID: 21756913 DOI: 10.1016/j.yjmcc.2011.06.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/20/2011] [Accepted: 06/24/2011] [Indexed: 10/18/2022]
Abstract
β-adrenergic receptors (β-ARs) modulate cardiotoxicity/cardioprotection through crosstalk with multiple signaling pathways. We have previously shown that β2-ARs are cardioprotective during exposure to oxidative stress induced by doxorubicin (DOX). DOX cardiotoxicity is mediated in part through a Ca(2+)-dependent opening of the mitochondrial permeability transition (MPT), however the signals linking a cell surface receptor like the β2-AR to regulators of mitochondrial function are not clear. The objective of this study was to assess mechanisms of crosstalk between β2-ARs and mitochondrial cell death pathways. DOX administered to WT mice resulted in no acute mortality, however 85% of β2-/- mice died within 30 min. Several pro- and anti-survival pathways were altered. The pro-survival kinase, εPKC, was decreased by 64% in β2-/- after DOX vs WT (p<0.01); the εPKC activator ψεRACK partially rescued these mice (47% reduction in mortality). Activity of the pro-survival kinase Akt decreased by 76% in β2-/- after DOX vs WT (p<0.01). The α1-antagonist prazosin restored Akt activity to normal and also partially reversed the mortality (45%). Deletion of the β2-AR increased rate of Ca(2+) release by 75% and peak [Ca(2+)](i) by 20% respectively in isolated cardiomyocytes; the Ca(2+) channel blocker verapamil also partially rescued the β2-/- (26%). Mitochondrial architecture was disrupted and complex I and II activities decreased by 40.9% and 34.6% respectively after DOX only in β2-/-. The MPT blocker cyclosporine reduced DOX mortality by 41% and prazosin plus cyclosporine acted synergistically to decrease mortality by 85%. β2-ARs activate pro-survival kinases and attenuate mitochondrial dysfunction during oxidative stress; absence of β2-ARs enhances cardiotoxicity via negative regulation of survival kinases and enhancement of intracellular Ca(2+), thus predisposing the mitochondria to opening of the MPT.
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Affiliation(s)
- Giovanni Fajardo
- Department of Pediatrics (Cardiology), Stanford University, Stanford, CA, USA
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Smith K, Semple D, Bhandari S, Seymour AML. Cellular basis of uraemic cardiomyopathy: a role for erythropoietin? Eur J Heart Fail 2010; 11:732-8. [PMID: 19633100 DOI: 10.1093/eurjhf/hfp093] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The use of erythropoietin (EPO) has revolutionized the treatment of anaemia associated with many conditions including chronic kidney disease (CKD). However, little is known of the cellular impact of EPO on the uraemic heart. The discovery that the EPO receptor (EPOR) is also expressed on non-haematopoietic cells including cardiomyocytes highlights a role of EPO beyond haematopoiesis. Animal models of heart failure have shown EPO can potentially reverse cardiac remodelling and improve myocardial function. Damage to the kidney, during uraemia, results in a decreased EPO production, which may render the uraemic heart more susceptible to damage and heart failure. Here we review current data on the cellular actions of EPO in models of left ventricular hypertrophy and heart failure and highlight parallels with the uraemic heart.
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Affiliation(s)
- Katie Smith
- Department of Biological Sciences, Hull York Medical School, University of Hull, Kingston-upon-Hull, UK
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Szewczyk A, Kajma A, Malinska D, Wrzosek A, Bednarczyk P, Zabłocka B, Dołowy K. Pharmacology of mitochondrial potassium channels: dark side of the field. FEBS Lett 2010; 584:2063-9. [PMID: 20178786 DOI: 10.1016/j.febslet.2010.02.048] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 01/25/2010] [Accepted: 02/15/2010] [Indexed: 11/25/2022]
Abstract
Mitochondrial potassium channels play an important role in cytoprotection. Potassium channels in the inner mitochondrial membrane are modulated by inhibitors and activators (potassium channel openers) previously described for plasma membrane potassium channels. The majority of mitochondrial potassium channel modulators exhibit a broad spectrum of off-target effects. These include uncoupling properties, inhibition of the respiratory chain and effects on cellular calcium homeostasis. Therefore, the rational application of channel inhibitors or activators is crucial to understanding the cellular consequences of mitochondrial channel inhibition or activation. Moreover, understanding their side-effects should facilitate the design of a specific mitochondrial channel opener with cytoprotective properties. In this review, we discuss the complex interactions of potassium channel inhibitors and activators with cellular structures.
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Affiliation(s)
- Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland.
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Kim MY, Seo EJ, Lee DH, Kim EJ, Kim HS, Cho HY, Chung EY, Lee SH, Baik EJ, Moon CH, Jung YS. Gadd45 is a novel mediator of cardiomyocyte apoptosis induced by ischaemia/hypoxia. Cardiovasc Res 2010; 87:119-26. [DOI: 10.1093/cvr/cvq048] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Agudo-López A, Miguel BG, Fernández I, Martínez AM. Involvement of mitochondria on neuroprotective effect of sphingosine-1-phosphate in cell death in an in vitro model of brain ischemia. Neurosci Lett 2010; 470:130-3. [PMID: 20045720 DOI: 10.1016/j.neulet.2009.12.070] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/22/2009] [Accepted: 12/28/2009] [Indexed: 01/16/2023]
Abstract
Sphingosine-1-phosphate (S1P) has been demonstrated to be an important regulator of cell death and survival. Although it has been suggested that the sphingolipid may act as a neuroprotector in the cell apoptosis induced by traumatic brain injury, the mechanisms involved in this action are unknown. In this study, the relationship between S1P and neuroprotective effect was studied in an in vitro model of ischemia, maintaining SH-SY5Y human neuroblastoma cells under oxygen-glucose deprivation (OGD). When cells were treated with 1 microM S1P simultaneously with OGD and recovery, cell viability increases in a dose-response manner. S1P treatment reduces significantly both necrosis and apoptosis cell death. On the other hand, the treatment with specific PKC epsilon (V1-2), prevents S1P protective effect of OGD/recovery-induced necrosis. Moreover, S1P treatment provokes the translocation of PKC epsilon to the mitochondria. From these results, it is reasonable to assume that S1P protection from necrosis is mediated by PKC epsilon. We also studied the action of S1P on mitochondrial inner membrane potential and mitochondrial Ca(2+) levels during ischemia. In this regard, we must point out that S1P treatment reduces the OGD-induced membrane depolarization and also reduces the increase of Ca(2+) in mitochondria during OGD. Results also indicate that mitochondria from OGD treated cells have significantly less ability to resist swelling on Ca(2+) loading than those obtained in presence of oxygen and glucose. Nevertheless, when S1P was added, this resistance increases considerably. These findings suggest that S1P may have a potential role as a neuroprotective agent in brain injury.
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Affiliation(s)
- Alba Agudo-López
- Departamento de Bioquímica y Biología Molecular I, Facultad de Química, Universidad Complutense de Madrid, E-28040 Madrid, Spain
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Ma G, Gao J, Fu Q, Jiang L, Wang R, Zhang Y, Liu K. Diazoxide Reverses the Enhanced Expression of KATP Subunits in Cholinergic Neurons Caused by Exposure to Aβ1-42. Neurochem Res 2009; 34:2133-40. [DOI: 10.1007/s11064-009-0007-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2009] [Indexed: 10/20/2022]
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Chaudhary KR, Batchu SN, Das D, Suresh MR, Falck JR, Graves JP, Zeldin DC, Seubert JM. Role of B-type natriuretic peptide in epoxyeicosatrienoic acid-mediated improved post-ischaemic recovery of heart contractile function. Cardiovasc Res 2009; 83:362-70. [PMID: 19401302 DOI: 10.1093/cvr/cvp134] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
AIMS This study examined the functional role of B-type natriuretic peptide (BNP) in epoxyeicosatrienoic acid (EET)-mediated cardioprotection in mice with targeted disruption of the sEH or Ephx2 gene (sEH null). METHODS AND RESULTS Isolated mouse hearts were perfused in the Langendorff mode and subjected to global no-flow ischaemia followed by reperfusion. Hearts were analysed for recovery of left ventricular developed pressure (LVDP), mRNA levels, and protein expression. Naïve hearts from sEH null mice had similar expression of preproBNP (Nppb) mRNA compared with wild-type (WT) hearts. However, significant increases in Nppb mRNA and BNP protein expression occurred during post-ischaemic reperfusion and correlated with improved post-ischaemic recovery of LVDP. Perfusion with the putative EET receptor antagonist 14,15-epoxyeicosa-5(Z)-enoic acid prior to ischaemia reduced the preproBNP mRNA in sEH null hearts. Inhibitor studies demonstrated that perfusion with the natriuretic peptide receptor type-A (NPR-A) antagonist, A71915, limited the improved recovery in recombinant full-length mouse BNP (rBNP)- and 11,12-EET-perfused hearts as well as in sEH null mice. Increased expression of phosphorylated protein kinase C epsilon and Akt were found in WT hearts perfused with either 11,12-EET or rBNP, while mitochondrial glycogen synthase kinase-3beta was significantly lower in the same samples. Furthermore, treatment with the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin abolished improved LVDP recovery in 11,12-EET-treated hearts but not did significantly inhibit recovery of rBNP-treated hearts. CONCLUSION Taken together, these data indicate that EET-mediated cardioprotection involves BNP and PI3K signalling events.
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Affiliation(s)
- Ketul R Chaudhary
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada T6G 2N8
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Park S, Kim MY, Lee DH, Lee SH, Baik EJ, Moon CH, Park SW, Ko EY, Oh SR, Jung YS. Methanolic extract of onion (Allium cepa) attenuates ischemia/hypoxia-induced apoptosis in cardiomyocytes via antioxidant effect. Eur J Nutr 2009; 48:235-42. [PMID: 19234663 DOI: 10.1007/s00394-009-0007-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 01/26/2009] [Indexed: 01/18/2023]
Abstract
BACKGROUND Although there is growing awareness of the beneficial potential of onion intake to lower the risk of cardiovascular disease, there is little information about the effect of onion on ischemic heart injury, one of the most common cardiovascular diseases. AIM OF THE STUDY This study investigates the effect of the methanol-soluble extract of onion on ischemic injury in heart-derived H9c2 cells in vitro and in rat hearts in vivo. The underlying mechanism is also investigated. METHODS To evaluate the effect of onion on ischemia-induced cell death, LDH release and TUNEL-positivity were assessed in H9c2 cells, and the infarct size was measured in a myocardial infarct model. To investigate the mechanism of the cardioprotection by onion, the reactive oxygen species (ROS) level and the mitochondrial membrane potential (DeltaPsi(m)) were measured using an imaging technique; the caspase-3 activity was assayed, and Western blotting was performed to examine cytochrome c release in H9c2 cells. RESULTS The methanolic extract of onion had a preventive effect on ischemia/hypoxia-induced apoptotic death in H9c2 cells in vitro and in rat heart in vivo. The onion extract (0.05 g/ml) inhibited the elevation of the ROS, mitochondrial membrane depolarization, cytochrome c release and caspase-3 activation during hypoxia in H9c2 cells. In the in vivo rat myocardial infarction model, onion extract (10 g/kg) significantly reduced the infarct size, the apoptotic cell death of the heart and the plasma MDA level. CONCLUSION In conclusion, the results of this study suggest that the methanolic extract of onion attenuates ischemia/hypoxia-induced apoptosis in heart-derived H9c2 cells in vitro and in rat hearts in vivo, through, at least in part, an antioxidant effect.
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Affiliation(s)
- Sok Park
- Department of Physiology, School of Medicine, Ajou University, #5 Woncheon-dong, Suwon, 443-749, South Korea
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New properties of mitochondrial ATP-regulated potassium channels. J Bioenerg Biomembr 2008; 40:325-35. [DOI: 10.1007/s10863-008-9153-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2008] [Accepted: 06/16/2008] [Indexed: 11/25/2022]
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Bruchez P, Sarre A, Kappenberger L, Raddatz E. The L-Type Ca+ and KATP channels may contribute to pacing-induced protection against anoxia-reoxygenation in the embryonic heart model. J Cardiovasc Electrophysiol 2008; 19:1196-202. [PMID: 18554212 DOI: 10.1111/j.1540-8167.2008.01218.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UNLABELLED L-Type Ca(2+) and K(ATP) Channels in Pacing-Induced Cardioprotection. AIMS The L-type Ca(2+) channel, the sarcolemmal (sarcK(ATP)), and mitochondrial K(ATP) (mitoK(ATP)) channels are involved in myocardial preconditioning. We aimed at determining to what extent these channels can also participate in pacing-induced cardioprotection. METHODS Hearts of 4-day-old chick embryos were paced in ovo during 12 hour using asynchronous intermittent ventricular stimulation at 110% of the intrinsic rate. Sham operated and paced hearts were then submitted in vitro to anoxia (30 minutes) and reoxygenation (60 minutes). These hearts were exposed to L-type Ca(2+) channel agonist Bay-K-8644 (BAY-K) or blocker verapamil, nonselective K(ATP) channel antagonist glibenclamide (GLIB), mitoK(ATP) channel agonist diazoxide (DIAZO), or antagonist 5-hydroxydecanoate. Electrocardiogram, electromechanical delay (EMD) reflecting excitation-contraction (E-C) coupling, and contractility were determined. RESULTS Under normoxia, heart rate, QT duration, conduction, EMD, and ventricular shortening were similar in sham and paced hearts. During reoxygenation, arrhythmias ceased earlier and ventricular EMD recovered faster in paced hearts than in sham hearts. In sham hearts, BAY-K (but not verapamil), DIAZO (but not 5-hydroxydecanoate) or GLIB accelerated recovery of ventricular EMD, reproducing the pacing-induced protection. By contrast, none of these agents further ameliorated recovery of the paced hearts. CONCLUSION The protective effect of chronic asynchronous pacing at near physiological rate on ventricular E-C coupling appears to be associated with subtle activation of L-type Ca(2+) channel, inhibition of sarcK(ATP) channel, and/or opening of mitoK(ATP) channel.
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Affiliation(s)
- Philippe Bruchez
- Department of Physiology, Faculty of Biology and Medicine, University Hospital, Lausanne, Switzerland
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Modulation of the c-Jun N-terminal kinase activity in the embryonic heart in response to anoxia-reoxygenation: involvement of the Ca2+ and mitoKATP channels. Mol Cell Biochem 2008; 313:133-8. [PMID: 18418700 DOI: 10.1007/s11010-008-9750-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2007] [Accepted: 03/28/2008] [Indexed: 10/22/2022]
Abstract
Whether the response of the fetal heart to ischemia-reperfusion is associated with activation of the c-Jun N-terminal kinase (JNK) pathway is not known. In contrast, involvement of the sarcolemmal L-type Ca2+ channel (LCC) and the mitochondrial KATP (mitoKATP) channel has been established. This work aimed at investigating the profile of JNK activity during anoxia-reoxygenation and its modulation by LCC and mitoK(ATP) channel. Hearts isolated from 4-day-old chick embryos were submitted to anoxia (30 min) and reoxygenation (60 min). Using the kinase assay method, the profile of JNK activity in the ventricle was determined every 10 min throughout anoxia-reoxygenation. Effects on JNK activity of the LCC blocker verapamil (10 nM), the mitoK(ATP) channel opener diazoxide (50 microM) and the blocker 5-hydroxydecanoate (5-HD, 500 microM), the mitochondrial Ca2+ uniporter (MCU) inhibitor Ru360 (10 microM), and the antioxidant N-(2-mercaptopropionyl) glycine (MPG, 1 mM) were determined. In untreated hearts, JNK activity was increased by 40% during anoxia and peaked fivefold relative to basal level after 30-40 min reoxygenation. This peak value was reduced by half by diazoxide and was tripled by 5-HD. Furthermore, the 5-HD-mediated stimulation of JNK activity during reoxygenation was abolished by diazoxide, verapamil or Ru360. MPG had no effect on JNK activity, whatever the conditions. None of the tested pharmacological agents altered JNK activity under basal normoxic conditions. Thus, in the embryonic heart, JNK activity exhibits a characteristic pattern during anoxia and reoxygenation and the respective open-state of LCC, MCU and mitoKATP channel can be a major determinant of JNK activity in a ROS-independent manner.
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Vinokur V, Leibowitz G, Grinberg L, Eliashar R, Berenshtein E, Chevion M. Diabetes and the heart: could the diabetic myocardium be protected by preconditioning? Redox Rep 2008; 12:246-56. [PMID: 17961296 DOI: 10.1179/135100007x239289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Both type 1 and type 2 diabetes (insulin-dependent and non-insulin dependent diabetes, respectively) are associated with increased risk for microvascular and macrovascular complications including retinopathy, neuropathy, nephropathy and atherosclerosis. Type 2 diabetes markedly increases the risk for cardiovascular morbidity and mortality, which has major public health implications. In this review, molecular mechanisms pertaining to diabetes-induced heart pathology are addressed.
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Affiliation(s)
- Vladimir Vinokur
- Department of Cellular Biochemistry and Human Genetics, The Hebrew University of Jerusalem, Jerusalem, Israel
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Holotnakova T, Ziegelhoffer A, Ohradanova A, Hulikova A, Novakova M, Kopacek J, Pastorek J, Pastorekova S. Induction of carbonic anhydrase IX by hypoxia and chemical disruption of oxygen sensing in rat fibroblasts and cardiomyocytes. Pflugers Arch 2007; 456:323-37. [DOI: 10.1007/s00424-007-0400-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 11/09/2007] [Accepted: 11/14/2007] [Indexed: 02/08/2023]
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Barnett ME, Madgwick DK, Takemoto DJ. Protein kinase C as a stress sensor. Cell Signal 2007; 19:1820-9. [PMID: 17629453 PMCID: PMC1986756 DOI: 10.1016/j.cellsig.2007.05.014] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 05/24/2007] [Accepted: 05/25/2007] [Indexed: 11/22/2022]
Abstract
While there are many reviews which examine the group of proteins known as protein kinase C (PKC), the focus of this article is to examine the cellular roles of two PKCs that are important for stress responses in neurological tissues (PKC gamma and epsilon) and in cardiac tissues (PKC epsilon). These two kinases, in particular, seem to have overlapping functions and interact with an identical target, connexin 43 (Cx43), a gap junction protein which is central to proper control of signals in both tissues. While PKC gamma and PKC epsilon both help protect neural tissue from ischemia, PKC epsilon is the primary PKC isoform responsible for responding to decreased oxygen, or ischemia, in the heart. Both do this through Cx43. It is clear that both PKC gamma and PKC epsilon are necessary for protection from ischemia. However, the importance of these kinases has been inferred from preconditioning experiments which demonstrate that brief periods of hypoxia protect neurological and cardiac tissues from future insults, and that this depends on the activation, translocation, or ability for PKC gamma and/or PKC epsilon to interact with distinct cellular targets, especially Cx43. This review summarizes the recent findings which define the roles of PKC gamma and PKC epsilon in cardiac and neurological functions and their relationships to ischemia/reperfusion injury. In addition, a biochemical comparison of PKC gamma and PKC epsilon and a proposed argument for why both forms are present in neurological tissue while only PKC epsilon is present in heart, are discussed. Finally, the biochemistry of PKCs and future directions for the field are discussed, in light of this new information.
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Affiliation(s)
- Micheal E Barnett
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506-3902, USA.
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