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Kovach CP, Al Koborssy D, Huang Z, Chelette BM, Fadool JM, Fadool DA. Mitochondrial Ultrastructure and Glucose Signaling Pathways Attributed to the Kv1.3 Ion Channel. Front Physiol 2016; 7:178. [PMID: 27242550 PMCID: PMC4871887 DOI: 10.3389/fphys.2016.00178] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/04/2016] [Indexed: 12/20/2022] Open
Abstract
Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3−∕−) results in “Super-smeller” mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3−∕− mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3−∕− male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3−∕− mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3−∕− mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very interested to understand how targeted disruption of the Kv1.3 channel in the OB can modify TEE. Our study demonstrates that Kv1.3 regulates mitochondrial structure and alters glucose utilization; two important metabolic changes that could drive whole system changes in metabolism initiated at the OB.
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Affiliation(s)
- Christopher P Kovach
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA
| | - Dolly Al Koborssy
- Program in Neuroscience, Florida State University Tallahassee, FL, USA
| | - Zhenbo Huang
- Program in Neuroscience, Florida State University Tallahassee, FL, USA
| | | | - James M Fadool
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA
| | - Debra A Fadool
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA; Institute of Molecular Biophysics, Florida State UniversityTallahassee, FL, USA
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Calabrese EJ. Pre- and post-conditioning hormesis in elderly mice, rats, and humans: its loss and restoration. Biogerontology 2016; 17:681-702. [DOI: 10.1007/s10522-016-9646-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 04/07/2016] [Indexed: 12/11/2022]
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53
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Heusch G. Treatment of Myocardial Ischemia/Reperfusion Injury by Ischemic and Pharmacological Postconditioning. Compr Physiol 2016; 5:1123-45. [PMID: 26140711 DOI: 10.1002/cphy.c140075] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Timely reperfusion is the only way to salvage ischemic myocardium from impending infarction. However, reperfusion also adds a further component to myocardial injury such that the ultimate infarct size is the result of both ischemia- and reperfusion-induced injury. Modification of reperfusion can attenuate reperfusion injury and thus reduce infarct size. Ischemic postconditioning is a maneuver of repeated brief interruption of reperfusion by short-lasting coronary occlusions which results in reduced infarct size. Cardioprotection by ischemic postconditioning is mediated through delayed reversal of acidosis and the activation of a complex signal transduction cascade, including triggers such as adenosine, bradykinin, and opioids, mediators such as protein kinases and, notably, mitochondrial function as effector. Inhibition of the mitochondrial permeability transition pore appears to be a final signaling step of ischemic postconditioning. Several drugs which recruit in part such signaling steps of ischemic postconditioning can induce cardioprotection, even when the drug is only administered at reperfusion, that is, there is also pharmacological postconditioning. Ischemic and pharmacological postconditioning have been translated to patients with acute myocardial infarction in proof-of-concept studies, but further mechanistic insight is needed to optimize the conditions and algorithms of cardioprotection by postconditioning.
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Affiliation(s)
- Gerd Heusch
- Institut für Pathophysiologie, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany
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Sádaba MC, Martín-Estal I, Puche JE, Castilla-Cortázar I. Insulin-like growth factor 1 (IGF-1) therapy: Mitochondrial dysfunction and diseases. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1267-78. [PMID: 27020404 DOI: 10.1016/j.bbadis.2016.03.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/18/2016] [Accepted: 03/21/2016] [Indexed: 12/19/2022]
Abstract
This review resumes the association between mitochondrial function and diseases, especially neurodegenerative diseases. Additionally, it summarizes the major role of IGF-1 as a mitochondrial protector, as studied in several experimental models (cirrhosis, aging …). The contribution of mitochondrial dysfunction to impairments in insulin metabolic signaling is also suggested by gene array analysis showing that reductions in gene expression, that regulates mitochondrial ATP production, are associated with insulin resistance and type 2 diabetes mellitus. Moreover, reductions in oxidative capacity of mitochondrial electron transport chain are manifested in obese, insulin-resistant and diabetic patients. Genetic and environmental factors, oxidative stress, and alterations in mitochondrial biogenesis can adversely affect mitochondrial function, leading to insulin resistance and several pathological conditions, such as type 2 diabetes. Finally, it remains essential to know the exact mechanisms involved in mitochondrial generation and metabolism, mitophagy, apoptosis, and oxidative stress to establish new targets in order to develop potentially effective therapies. One of the newest targets to recover mitochondrial dysfunction could be the administration of IGF-1 at low doses. In the last years, it has been observed that IGF-1 therapy has several beneficial effects: restores physiological IGF-1 levels; improves insulin resistance and lipid metabolism; exerts mitochondrial protection; and has hepatoprotective, neuroprotective, antioxidant and antifibrogenic effects. In consequence, treatment of mitochondrial dysfunctions with low doses of IGF-1 could be a powerful and useful effective therapy to restore normal mitochondrial functions.
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Affiliation(s)
- M C Sádaba
- University CEU-San Pablo, School of Medicine, Department of Physiology, Institute of Applied Molecular Medicine (IMMA), Madrid, Spain
| | - I Martín-Estal
- School of Medicine, Tecnologico de Monterrey, Monterrey, Mexico
| | - J E Puche
- University CEU-San Pablo, School of Medicine, Department of Physiology, Institute of Applied Molecular Medicine (IMMA), Madrid, Spain
| | - I Castilla-Cortázar
- School of Medicine, Tecnologico de Monterrey, Monterrey, Mexico; Fundación de Investigación HM Hospitales, Madrid, Spain.
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55
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Goharbari MH, Shadboores A, Abdollahi M. Inhibitory Effects of Thyroid Hormones on Mitochondrial
Oxidative Stress: A Systematic Review. INT J PHARMACOL 2016. [DOI: 10.3923/ijp.2016.249.261] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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56
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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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57
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Abdelwahid E, Kalvelyte A, Stulpinas A, de Carvalho KAT, Guarita-Souza LC, Foldes G. Stem cell death and survival in heart regeneration and repair. Apoptosis 2016; 21:252-68. [PMID: 26687129 PMCID: PMC5200890 DOI: 10.1007/s10495-015-1203-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function.
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Affiliation(s)
- Eltyeb Abdelwahid
- Feinberg School of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University, 303 E. Chicago Ave., Tarry 14-725, Chicago, IL, 60611, USA.
| | - Audrone Kalvelyte
- Department of Molecular Cell Biology, Vilnius University Institute of Biochemistry, Vilnius, Lithuania
| | - Aurimas Stulpinas
- Department of Molecular Cell Biology, Vilnius University Institute of Biochemistry, Vilnius, Lithuania
| | - Katherine Athayde Teixeira de Carvalho
- Cell Therapy and Biotechnology in Regenerative Medicine Research Group, Pequeno Príncipe Faculty, Pelé Pequeno Príncipe Institute, Curitiba, Paraná, 80250-200, Brazil
| | - Luiz Cesar Guarita-Souza
- Experimental Laboratory of Institute of Biological and Health Sciences of Pontifical Catholic University of Parana, Curitiba, Paraná, 80215-901, Brazil
| | - Gabor Foldes
- National Heart and Lung Institute, Imperial College London, Imperial Centre for Experimental and Translational Medicine, Du Cane Road, London, W12 0NN, UK
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58
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Mitochondrial ATP-sensitive potassium channel opening inhibits isoproterenol-induced cardiac hypertrophy by preventing oxidative damage. J Cardiovasc Pharmacol 2016; 65:393-7. [PMID: 25850726 DOI: 10.1097/fjc.0000000000000210] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cardiac hypertrophy is a chronic complex disease that occurs in response to hemodynamic load and is accompanied by oxidative stress and mitochondrial dysfunction. Mitochondrial ATP-sensitive K channels (mitoKATPs) have previously been shown to prevent oxidative cardiac damage under conditions of ischemia/reperfusion. However, the effect of these channels on cardiac hypertrophy has not been tested to date. In this study, we show that treatment of Swiss mice with isoproterenol (30 mg·kg·d) induces cardiac hypertrophy while significantly decreasing the levels of reduced protein thiols, glutathione, catalase, and superoxide dismutase activity, indicative of a condition of oxidative imbalance. Treatment with diazoxide (a mitoKATP opener, 5 mg·kg·d) normalized the levels of protein thiols and reduced glutathione, rescued superoxide dismutase activity, and significantly prevented cardiac hypertrophy. The protective effects of diazoxide were mitigated by the mitoKATP blockers 5-hydroxydecanoate (5 mg·kg·d) and glibenclamide (3 mg·kg·d), demonstrating that they were related to activation of the channel. Taken together, our results establish that mitoKATP activation promotes very robust prevention of cardiac hypertrophy and associated oxidative imbalance and suggest that these channels can be important drug targets for the pharmacological control of cardiac hypertrophy.
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59
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Akopova O, Nosar V, Gavenauskas B, Bratus L, Kolchinskaya L, Mankovska I, Sagach V. The effect of atp-dependent potassium uptake on mitochondrial functions under acute hypoxia. J Bioenerg Biomembr 2016; 48:67-75. [PMID: 26739597 DOI: 10.1007/s10863-015-9642-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/28/2015] [Indexed: 12/22/2022]
Abstract
The opening of mitochondrial K(+) АТР-channel (mtK(+) АТР-channel) is supposed to be important in the modulation of mitochondrial functions under hypoxia, but the underlying mechanisms have not been clarified yet. The aim of this work was to study the effect of acute hypoxia on mtK(+) АТР-channel activity and to estimate the contribution of the channel in the modulation of mitochondrial functions. MtK(+) АТР-channel activity was assessed polarographically from the rate of State 4 respiration and by potentiometric monitoring of potassium efflux from deenergized mitochondria. It was shown that hypoxia reliably increased mtK(+) АТР-channel activity, which resulted in the changes of respiration rates (increase of State 4 and suppression of State 3 respiration), uncoupling (the decrease of respiratory control ratio) and suppression of phosphorylation. These effects were well mimicked by mtK(+) АТР-channel opener diazoxide (DZ) in isolated rat liver mitochondria. MtK(+) АТР-channel opening in vitro suppressed phosphorylation too, but increased phosphorylation efficiency, while mtK(+) АТР-channel blockers reduced it dramatically. The correlation was established between mtK(+) АТР-channel activity and the endurance of the rats to physical training under hypoxia. Hypoxia improved physical endurance, but treatment by mtK(+) АТР-channel blockers glibenklamide and 5-hydroxydecanoate (5-HD) prior to hypoxia strongly reduced both the channel activity and the endurance limits. This was in accord with the observation that under glibenklamide and 5-HD administration hypoxia failed to restore mtK(+) АТР-channel activity. Based on the experiments, we came to the conclusion that mtK(+) АТР-channel opening played a decisive role in the regulation of energy metabolism under acute hypoxia via the modulation of phosphorylation system in mitochondria.
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Affiliation(s)
- Olga Akopova
- Circulation Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz str. 4, 01601, Kiev, Ukraine.
| | - Valentina Nosar
- Hypoxic States Research Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine
| | - Bronislav Gavenauskas
- Hypoxic States Research Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine
| | - Larissa Bratus
- Hypoxic States Research Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine
| | - Liudmila Kolchinskaya
- Circulation Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz str. 4, 01601, Kiev, Ukraine
| | - Iryna Mankovska
- Hypoxic States Research Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine
| | - Vadim Sagach
- Circulation Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz str. 4, 01601, Kiev, Ukraine
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60
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Miura M, Nagano T, Murai N, Taguchi Y, Handoh T, Satoh M, Miyata S, Miller L, Shindoh C, Stuyvers BD. Effect of Carbenoxolone on Arrhythmogenesis in Rat Ventricular Muscle. Circ J 2016; 80:76-84. [DOI: 10.1253/circj.cj-15-0401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Masahito Miura
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
| | - Tsuyoshi Nagano
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
| | - Naomi Murai
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
| | - Yuhto Taguchi
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
| | - Tetsuya Handoh
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
| | - Minami Satoh
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
| | - Satoshi Miyata
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine
| | - Lawson Miller
- Faculty of Medicine, Biomedical Sciences, Memorial University
| | - Chiyohiko Shindoh
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine
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61
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ZÁLEŠÁK M, BLAŽÍČEK P, GABLOVSKÝ I, LEDVÉNYIOVÁ V, BARTEKOVÁ M, ZIEGELHÖFFER A, RAVINGEROVÁ T. Impaired PI3K/Akt Signaling as a Potential Cause of Failure to Precondition Rat Hearts Under Conditions of Simulated Hyperglycemia. Physiol Res 2015; 64:633-41. [DOI: 10.33549/physiolres.932883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The aim of the study was to evaluate the impact of simulated acute hyperglycemia (HG) on PI3K/Akt signaling in preconditioned and non-preconditioned isolated rat hearts perfused with Krebs-Henseleit solution containing normal (11 mmol/l) or elevated (22 mmol/l) glucose subjected to ischemia-reperfusion. Ischemic preconditioning (IP) was induced by two 5-min cycles of coronary occlusion followed by 5-min reperfusion. Protein levels of Akt, phosphorylated (activated) Akt (P-Akt), as well as contents of BAX protein were assayed (Western blotting) in cytosolic fraction of myocardial tissue samples taken prior to and after 30-min global ischemia and 40-min reperfusion. In “normoglycemic” conditions (NG), IP significantly increased P-Akt at the end of long-term ischemia, while reperfusion led to its decrease together with the decline of BAX levels as compared to non-preconditioned hearts. On the contrary, under HG conditions, P-Akt tended to decline in IP-hearts after long-term ischemia, and it was significantly higher after reperfusion than in non-preconditioned controls. No significant influence of IP on BAX levels at the end of I/R was observed under HG conditions. It seems that high glucose may influence IP-induced activation of Akt and its downstream targets, as well as maintain persistent Akt activity that may be detrimental for the heart under above conditions.
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Affiliation(s)
- M. ZÁLEŠÁK
- Institute for Heart Research, Slovak Academy of Sciences and Centre of Excellence of SAS NOREG Bratislava, Slovak Republic
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62
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Radulovic M, Anand P, Korsten MA, Gong B. Targeting Ion Channels: An Important Therapeutic Implication in Gastrointestinal Dysmotility in Patients With Spinal Cord Injury. J Neurogastroenterol Motil 2015; 21:494-502. [PMID: 26424038 PMCID: PMC4622131 DOI: 10.5056/jnm15061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 06/10/2015] [Accepted: 07/06/2015] [Indexed: 01/04/2023] Open
Abstract
Gastrointestinal (GI) dysmotility is a severe, and common complication in patients with spinal cord injury (SCI). Current therapeutic methods using acetylcholine analogs or laxative agents have unwanted side effects, besides often fail to have desired effect. Various ion channels such as ATP-sensitive potassium (KATP) channel, calcium ions (Ca2+)-activated potassium ions (K+) channels, voltage-sensitive Ca2+ channels and chloride ion (Cl−) channels are abundantly expressed in GI tissues, and play an important role in regulating GI motility. The release of neurotransmitters from the enteric nerve terminal, innervating GI interstitial cells of Cajal (ICC), and smooth muscle cells (SMC), causes inactivation of K+ and Cl− channels, increasing Ca2+ influx into cytoplasm, resulting in membrane depolarization and smooth muscle contraction. Thus, agents directly regulating ion channels activity either in ICC or in SMC may affect GI peristalsis and would be potential therapeutic target for the treatment of GI dysmotility with SCI.
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Affiliation(s)
- Miroslav Radulovic
- Department of Medicine Icahn School of Medicine at Mount Sinai, New York, NY, USA.,National Center of Excellence for the Medical Consequences of SCI, James J Peters Veteran Affairs Medical Center, Bronx, NY, USA
| | - Preeti Anand
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Mark A Korsten
- Department of Medicine Icahn School of Medicine at Mount Sinai, New York, NY, USA.,National Center of Excellence for the Medical Consequences of SCI, James J Peters Veteran Affairs Medical Center, Bronx, NY, USA
| | - Bing Gong
- Department of Medicine Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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63
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da Luz VF, Otsuki DA, Gonzalez MMC, Negri EM, Caldini EG, Damaceno-Rodrigues NR, Malbouisson LMS, Viana BG, Vane MF, Carmona MJC. Myocardial protection induced by fentanyl in pigs exposed to high-dose adrenaline. Clin Exp Pharmacol Physiol 2015; 42:1098-107. [DOI: 10.1111/1440-1681.12456] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 06/30/2015] [Accepted: 07/09/2015] [Indexed: 01/02/2023]
Affiliation(s)
| | - Denise Aya Otsuki
- University of Sao Paulo Medical School; Department of Anaesthesiology; São Paulo Brazil
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64
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Sanbe A. Protein folding disease and ATP sensitive potassium channel. Nihon Yakurigaku Zasshi 2015; 146:16-20. [PMID: 26165337 DOI: 10.1254/fpj.146.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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65
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Mitochondrial ATP-Mg/Pi carrier SCaMC-3/Slc25a23 counteracts PARP-1-dependent fall in mitochondrial ATP caused by excitotoxic insults in neurons. J Neurosci 2015; 35:3566-81. [PMID: 25716855 DOI: 10.1523/jneurosci.2702-14.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Glutamate excitotoxicity is caused by sustained activation of neuronal NMDA receptors causing a large Ca(2+) and Na(+) influx, activation of poly(ADP ribose) polymerase-1 (PARP-1), and delayed Ca(2+) deregulation. Mitochondria undergo early changes in membrane potential during excitotoxicity, but their precise role in these events is still controversial. Using primary cortical neurons derived from mice, we show that NMDA exposure results in a rapid fall in mitochondrial ATP in neurons deficient in SCaMC-3/Slc25a23, a Ca(2+)-regulated mitochondrial ATP-Mg/Pi carrier. This fall is associated with blunted increases in respiration and a delayed decrease in cytosolic ATP levels, which are prevented by PARP-1 inhibitors or by SCaMC-3 activity promoting adenine nucleotide uptake into mitochondria. SCaMC-3 KO neurons show an earlier delayed Ca(2+) deregulation, and SCaMC-3-deficient mitochondria incubated with ADP or ATP-Mg had reduced Ca(2+) retention capacity, suggesting a failure to maintain matrix adenine nucleotides as a cause for premature delayed Ca(2+) deregulation. SCaMC-3 KO neurons have higher vulnerability to in vitro excitotoxicity, and SCaMC-3 KO mice are more susceptible to kainate-induced seizures, showing that early PARP-1-dependent fall in mitochondrial ATP levels, counteracted by SCaMC-3, is an early step in the excitotoxic cascade.
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66
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Cordeiro B, Terentyev D, Clements RT. BKCa channel activation increases cardiac contractile recovery following hypothermic ischemia/reperfusion. Am J Physiol Heart Circ Physiol 2015; 309:H625-33. [PMID: 26071546 DOI: 10.1152/ajpheart.00818.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 06/04/2015] [Indexed: 01/15/2023]
Abstract
Mitochondrial Ca(2+)-activated large-conductance K(+) (BKCa) channels are thought to provide protection during ischemic insults in the heart. Rottlerin (mallotoxin) has been implicated as a potent BKCa activator. The purpose of this study was twofold: 1) to investigate the efficacy of BKCa channel activation as a cardioprotective strategy during ischemic cardioplegic arrest and reperfusion (CP/R) and 2) to assess the specificity of rottlerin for BKCa channels. Wild-type (WT) and BKCa knockout (KO) mice were subjected to an isolated heart model of ischemic CP/R. A mechanism of rottlerin-induced cardioprotection was also investigated using H9c2 cells subjected to in vitro CP/reoxygenation and assessed for mitochondrial membrane potential and reactive oxygen species (ROS) production. CP/R decreased left ventricular developed pressure, positive and negative first derivatives of left ventricular pressure, and coronary flow (CF) in WT mice. Rottlerin dose dependently increased the recovery of left ventricular function and CF to near baseline levels. BKCa KO hearts treated with or without 500 nM rottlerin were similar to WT CP hearts. H9c2 cells subjected to in vitro CP/R displayed reduced mitochondrial membrane potential and increased ROS generation, both of which were significantly normalized by rottlerin. We conclude that activation of BKCa channels rescues ischemic damage associated with CP/R, likely via effects on improved mitochondrial membrane potential and reduced ROS generation.
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Affiliation(s)
- Brenda Cordeiro
- Cardiovascular Research Center and Department of Surgery, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island
| | - Dmitry Terentyev
- Cardiovascular Research Center and Department of Surgery, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island
| | - Richard T Clements
- Cardiovascular Research Center and Department of Surgery, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island
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Yang KC, Kyle JW, Makielski JC, Dudley SC. Mechanisms of sudden cardiac death: oxidants and metabolism. Circ Res 2015; 116:1937-55. [PMID: 26044249 PMCID: PMC4458707 DOI: 10.1161/circresaha.116.304691] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 02/09/2015] [Indexed: 02/07/2023]
Abstract
Ventricular arrhythmia is the leading cause of sudden cardiac death (SCD). Deranged cardiac metabolism and abnormal redox state during cardiac diseases foment arrhythmogenic substrates through direct or indirect modulation of cardiac ion channel/transporter function. This review presents current evidence on the mechanisms linking metabolic derangement and excessive oxidative stress to ion channel/transporter dysfunction that predisposes to ventricular arrhythmias and SCD. Because conventional antiarrhythmic agents aiming at ion channels have proven challenging to use, targeting arrhythmogenic metabolic changes and redox imbalance may provide novel therapeutics to treat or prevent life-threatening arrhythmias and SCD.
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Affiliation(s)
- Kai-Chien Yang
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.)
| | - John W Kyle
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.)
| | - Jonathan C Makielski
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.).
| | - Samuel C Dudley
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.).
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68
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Umaru B, Pyriochou A, Kotsikoris V, Papapetropoulos A, Topouzis S. ATP-sensitive potassium channel activation induces angiogenesis in vitro and in vivo. J Pharmacol Exp Ther 2015; 354:79-87. [PMID: 25977483 DOI: 10.1124/jpet.114.222000] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 05/13/2015] [Indexed: 12/19/2022] Open
Abstract
Intense research is conducted to identify new molecular mechanisms of angiogenesis. Previous studies have shown that the angiogenic effects of hydrogen sulfide (H2S) depend on the activation of ATP-sensitive potassium channels (KATP) and that C-type natriuretic peptide (CNP), which can act through KATP, promotes endothelial cell growth. We therefore investigated whether direct KATP activation induces angiogenic responses and whether it is required for the endothelial responses to CNP or vascular endothelial growth factor (VEGF). Chick chorioallantoic membrane (CAM) angiogenesis was similarly enhanced by the direct KATP channel activator 2-nicotinamidoethyl acetate (SG-209) and by CNP or VEGF. The KATP inhibitors glibenclamide and 5-hydroxydecanoate (5-HD) reduced basal and abolished CNP-induced CAM angiogenesis. In vitro, the direct KATP openers nicorandil and SG-209 and the polypeptides VEGF and CNP increased proliferation and migration in bEnd.3 mouse endothelial cells. In addition, VEGF and CNP induced cord-like formation on Matrigel by human umbilical vein endothelial cells (HUVECs). All these in vitro endothelial responses were effectively abrogated by glibenclamide or 5-HD. In HUVECs, a small-interfering RNA-mediated decrease in the expression of the inwardly rectifying potassium channel (Kir) 6.1 subunit impaired cell migration and network morphogenesis in response to either SG-209 or CNP. We conclude that 1) direct pharmacologic activation of KATP induces angiogenic effects in vitro and in vivo, 2) angiogenic responses to CNP and VEGF depend on KATP activation and require the expression of the Kir6.1 KATP subunit, and 3) KATP activation may underpin angiogenesis to a variety of vasoactive stimuli, including H2S, VEGF, and CNP.
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Affiliation(s)
- Bukar Umaru
- Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Rio-Patras, Greece (B.U., A.Py., V.K., S.T.); and Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (A.Pa.)
| | - Anastasia Pyriochou
- Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Rio-Patras, Greece (B.U., A.Py., V.K., S.T.); and Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (A.Pa.)
| | - Vasileios Kotsikoris
- Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Rio-Patras, Greece (B.U., A.Py., V.K., S.T.); and Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (A.Pa.)
| | - Andreas Papapetropoulos
- Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Rio-Patras, Greece (B.U., A.Py., V.K., S.T.); and Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (A.Pa.)
| | - Stavros Topouzis
- Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Rio-Patras, Greece (B.U., A.Py., V.K., S.T.); and Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (A.Pa.)
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Abstract
Reperfusion is mandatory to salvage ischemic myocardium from infarction, but reperfusion per se contributes to injury and ultimate infarct size. Therefore, cardioprotection beyond that by timely reperfusion is needed to reduce infarct size and improve the prognosis of patients with acute myocardial infarction. The conditioning phenomena provide such cardioprotection, insofar as brief episodes of coronary occlusion/reperfusion preceding (ischemic preconditioning) or following (ischemic postconditioning) sustained myocardial ischemia with reperfusion reduce infarct size. Even ischemia/reperfusion in organs remote from the heart provides cardioprotection (remote ischemic conditioning). The present review characterizes the signal transduction underlying the conditioning phenomena, including their physical and chemical triggers, intracellular signal transduction, and effector mechanisms, notably in the mitochondria. Cardioprotective signal transduction appears as a highly concerted spatiotemporal program. Although the translation of ischemic postconditioning and remote ischemic conditioning protocols to patients with acute myocardial infarction has been fairly successful, the pharmacological recruitment of cardioprotective signaling has been largely disappointing to date.
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Affiliation(s)
- Gerd Heusch
- From the Institute for Pathophysiology, West German Heart and Vascular Centre, University of Essen Medical School, Essen, Germany.
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70
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Mitochondrial biology, targets, and drug delivery. J Control Release 2015; 207:40-58. [PMID: 25841699 DOI: 10.1016/j.jconrel.2015.03.036] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 02/07/2023]
Abstract
In recent years, mitochondrial medicine has emerged as a new discipline resting at the intersection of mitochondrial biology, pathology, and pharmaceutics. The central role of mitochondria in critical cellular processes such as metabolism and apoptosis has placed mitochondria at the forefront of cell science. Advances in mitochondrial biology have revealed that these organelles continually undergo fusion and fission while functioning independently and in complex cellular networks, establishing direct membrane contacts with each other and with other organelles. Understanding the diverse cellular functions of mitochondria has contributed to understanding mitochondrial dysfunction in disease states. Polyplasmy and heteroplasmy contribute to mitochondrial phenotypes and associated dysfunction. Residing at the center of cell biology, cellular functions, and disease pathology and being laden with receptors and targets, mitochondria are beacons for pharmaceutical modification. This review presents the current state of mitochondrial medicine with a focus on mitochondrial function, dysfunction, and common disease; mitochondrial receptors, targets, and substrates; and mitochondrial drug design and drug delivery with a focus on the application of nanotechnology to mitochondrial medicine. Mitochondrial medicine is at the precipice of clinical translation; the objective of this review is to aid in the advancement of mitochondrial medicine from infancy to application.
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Laskowski M, Kicinska A, Szewczyk A, Jarmuszkiewicz W. Mitochondrial large-conductance potassium channel from Dictyostelium discoideum. Int J Biochem Cell Biol 2015; 60:167-75. [DOI: 10.1016/j.biocel.2015.01.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 12/02/2014] [Accepted: 01/07/2015] [Indexed: 12/23/2022]
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Smit KF, Weber NC, Hollmann MW, Preckel B. Noble gases as cardioprotectants - translatability and mechanism. Br J Pharmacol 2015; 172:2062-73. [PMID: 25363501 DOI: 10.1111/bph.12994] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 10/06/2014] [Accepted: 10/21/2014] [Indexed: 01/03/2023] Open
Abstract
Several noble gases, although classified as inert substances, exert a tissue-protective effect in different experimental models when applied before organ ischaemia as an early or late preconditioning stimulus, after ischaemia as a post-conditioning stimulus or when given in combination before, during and/or after ischaemia. A wide range of organs can be protected by these inert substances, in particular cardiac and neuronal tissue. In this review we summarize the data on noble gas-induced cardioprotection, focusing on the underlying protective mechanisms. We will also look at translatability of experimental data to the clinical situation.
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Affiliation(s)
- Kirsten F Smit
- Department of Anaesthesiology, Laboratory of Experimental Intensive Care and Anaesthesiology (L.E.I.C.A), Academic Medical Centre (AMC), Amsterdam, The Netherlands
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Sunaga D, Tanno M, Kuno A, Ishikawa S, Ogasawara M, Yano T, Miki T, Miura T. Accelerated recovery of mitochondrial membrane potential by GSK-3β inactivation affords cardiomyocytes protection from oxidant-induced necrosis. PLoS One 2014; 9:e112529. [PMID: 25390651 PMCID: PMC4229200 DOI: 10.1371/journal.pone.0112529] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 10/06/2014] [Indexed: 12/20/2022] Open
Abstract
Loss of mitochondrial membrane potential (ΔΨm) is known to be closely linked to cell death by various insults. However, whether acceleration of the ΔΨm recovery process prevents cell necrosis remains unclear. Here we examined the hypothesis that facilitated recovery of ΔΨm contributes to cytoprotection afforded by activation of the mitochondrial ATP-sensitive K+ (mKATP) channel or inactivation of glycogen synthase kinase-3β (GSK-3β). ΔΨm of H9c2 cells was determined by tetramethylrhodamine ethyl ester (TMRE) before or after 1-h exposure to antimycin A (AA), an inducer of reactive oxygen species (ROS) production at complex III. Opening of the mitochondrial permeability transition pore (mPTP) was determined by mitochondrial loading of calcein. AA reduced ΔΨm to 15±1% of the baseline and induced calcein leak from mitochondria. ΔΨm was recovered to 51±3% of the baseline and calcein-loadable mitochondria was 6±1% of the control at 1 h after washout of AA. mKATP channel openers improved the ΔΨm recovery and mitochondrial calcein to 73±2% and 30±7%, respectively, without change in ΔΨm during AA treatment. Activation of the mKATP channel induced inhibitory phosphorylation of GSK-3β and suppressed ROS production, LDH release and apoptosis after AA washout. Knockdown of GSK-3β and pharmacological inhibition of GSK-3β mimicked the effects of mKATP channel activation. ROS scavengers administered at the time of AA removal also improved recovery of ΔΨm. These results indicate that inactivation of GSK-3β directly or indirectly by mKATP channel activation facilitates recovery of ΔΨm by suppressing ROS production and mPTP opening, leading to cytoprotection from oxidant stress-induced cell death.
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Affiliation(s)
- Daisuke Sunaga
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masaya Tanno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Atsushi Kuno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Satoko Ishikawa
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Makoto Ogasawara
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Toshiyuki Yano
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takayuki Miki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
- * E-mail:
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Efeitos de dexmedetomidina em conjunto com o pré‐condicionamento isquêmico remoto em lesão de isquemia‐reperfusão renal em ratos. Braz J Anesthesiol 2014; 64:382-90. [DOI: 10.1016/j.bjan.2014.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 01/02/2014] [Indexed: 11/17/2022] Open
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75
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Alavian KN, Dworetzky SI, Bonanni L, Zhang P, Sacchetti S, Li H, Signore AP, Smith PJS, Gribkoff VK, Jonas EA. The mitochondrial complex V-associated large-conductance inner membrane current is regulated by cyclosporine and dexpramipexole. Mol Pharmacol 2014; 87:1-8. [PMID: 25332381 DOI: 10.1124/mol.114.095661] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Inefficiency of oxidative phosphorylation can result from futile leak conductance through the inner mitochondrial membrane. Stress or injury may exacerbate this leak conductance, putting cells, and particularly neurons, at risk of dysfunction and even death when energy demand exceeds cellular energy production. Using a novel method, we have recently described an ion conductance consistent with mitochondrial permeability transition pore (mPTP) within the c-subunit of the ATP synthase. Excitotoxicity, reactive oxygen species-producing stimuli, or elevated mitochondrial matrix calcium opens the channel, which is inhibited by cyclosporine A and ATP/ADP. Here we show that ATP and the neuroprotective drug dexpramipexole (DEX) inhibited an ion conductance consistent with this c-subunit channel (mPTP) in brain-derived submitochondrial vesicles (SMVs) enriched for F1FO ATP synthase (complex V). Treatment of SMVs with urea denatured extramembrane components of complex V, eliminated DEX- but not ATP-mediated current inhibition, and reduced binding of [(14)C]DEX. Direct effects of DEX on the synthesis and hydrolysis of ATP by complex V suggest that interaction of the compound with its target results in functional conformational changes in the enzyme complex. [(14)C]DEX bound specifically to purified recombinant b and oligomycin sensitivity-conferring protein subunits of the mitochondrial F1FO ATP synthase. Previous data indicate that DEX increased the efficiency of energy production in cells, including neurons. Taken together, these studies suggest that modulation of a complex V-associated inner mitochondrial membrane current is metabolically important and may represent an avenue for the development of new therapeutics for neurodegenerative disorders.
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Affiliation(s)
- Kambiz N Alavian
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Steven I Dworetzky
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Laura Bonanni
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Ping Zhang
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Silvio Sacchetti
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Hongmei Li
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Armando P Signore
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Peter J S Smith
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Valentin K Gribkoff
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
| | - Elizabeth A Jonas
- Department of Internal Medicine (K.N.A., P.Z., S.S., H.L., E.A.J.) and Department of Neurobiology (E.A.J.), Yale University School of Medicine, New Haven, Connecticut; Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom (K.N.A.); Department of Neuroscience, Imaging and Clinical Sciences, University G.d'Annunzio of Chieti-Pescara, Chieti-Pescara, Italy (L.B.); Knopp Biosciences LLC, Pittsburgh, Pennsylvania (S.I.D., A.P.S., V.K.G.); and Biocurrents Research Center, Marine Biological Laboratory, Woods Hole, Massachusetts (P.J.S.S.)
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Shiraishi T, Tamura Y, Taniguchi K, Higaki M, Ueda S, Shima T, Nagura M, Nakagawa T, Johnson RJ, Uchida S. Combination of ACE inhibitor with nicorandil provides further protection in chronic kidney disease. Am J Physiol Renal Physiol 2014; 307:F1313-22. [PMID: 25320353 DOI: 10.1152/ajprenal.00521.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An inhibition in the renin-angiotensin system (RAS) is one of the most widely used therapies to treat chronic kidney disease. However, its effect is occasionally not sufficient and additional treatments may be required. Recently, we reported that nicorandil exhibited renoprotective effects in a mouse model of diabetic nephropathy. Here we examined if nicorandil can provide an additive protection on enalapril in chronic kidney disease. Single treatment with either enalapril or nicorandil significantly ameliorated glomerular and tubulointerstitial injury in the rat remnant kidney while the combination of these two compounds provided additive effects. In addition, an increase in oxidative stress in remnant kidney was also blocked by either enalapril or nicorandil while the combination of the drugs was more potent. A mechanism was likely due for nicorandil to preventing manganase superoxide dismutase (MnSOD) and sirtuin (Sirt)3 from being reduced in injured kidneys. A study with cultured podocytes indicated that the antioxidative effect could be mediated through sulfonylurea receptor (SUR) in the mitochondrial KATP channel since blocking SUR with glibenclamide reduced MnSOD and Sirt3 expression in podocytes. In conclusion, nicorandil may synergize with enalapril to provide superior protection in chronic kidney disease.
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Affiliation(s)
- Takeshi Shiraishi
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Yoshifuru Tamura
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Kei Taniguchi
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Masato Higaki
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Shuko Ueda
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Tomoko Shima
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Michito Nagura
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Takahiko Nakagawa
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; and
| | - Richard J Johnson
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado
| | - Shunya Uchida
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan;
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Solhjoo S, O'Rourke B. Mitochondrial instability during regional ischemia-reperfusion underlies arrhythmias in monolayers of cardiomyocytes. J Mol Cell Cardiol 2014; 78:90-9. [PMID: 25268650 DOI: 10.1016/j.yjmcc.2014.09.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 09/16/2014] [Accepted: 09/19/2014] [Indexed: 01/05/2023]
Abstract
Regional depolarization of the mitochondrial network can alter cellular electrical excitability and increase the propensity for reentry, in part, through the opening of sarcolemmal KATP channels. Mitochondrial inner membrane potential (ΔΨm) instability or oscillation can be induced in myocytes by exposure to reactive oxygen species (ROS), laser excitation, or glutathione depletion, and is thought to be a major factor in arrhythmogenesis during ischemia-reperfusion. Nevertheless, the correlation between ΔΨm recovery kinetics and reperfusion-induced arrhythmias has been difficult to demonstrate experimentally. Here, we investigate the relationship between subcellular changes in ΔΨm, cellular glutathione redox potential, electrical excitability, and wave propagation during coverslip-induced ischemia-reperfusion (IR) in neonatal rat ventricular myocyte (NRVM) monolayers. Ischemia led to decreased action potential amplitude and duration followed by electrical inexcitability after ~15min of ischemia. ΔΨm depolarization occurred in two phases during ischemia: in phase 1 (<30min ischemia), mitochondrial clusters within individual NRVMs depolarized, while phase 2 ΔΨm depolarization (30-60min) was characterized by global functional collapse of the mitochondrial network across the whole ischemic region of the monolayer, typically involving a propagating metabolic wave. Oxidation of the glutathione (GSSG:GSH) redox potential occurred during ischemia, followed by recovery upon reperfusion (i.e., lifting the coverslip). ΔΨm recovered in the mitochondria of individual myocytes quite rapidly upon reperfusion (<5min), but was highly unstable, characterized by subcellular oscillations or flickering of clusters of mitochondria in NRVMs across the reperfused region. Electrical excitability also recovered in a heterogeneous manner, providing an arrhythmogenic substrate which led to formation of sustained reentry. Treatment with 4'-chlorodiazepam, a peripheral benzodiazepine receptor ligand, prevented ΔΨm oscillation, improved GSH recovery rate, and prevented reentry during reperfusion, indicating that stabilization of mitochondrial network dynamics is important for preventing post-ischemic arrhythmias. This article is part of a Special Issue entitled "Mitochondria: From Basic Mitochondrial Biology to Cardiovascular Disease".
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Affiliation(s)
- Soroosh Solhjoo
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Brian O'Rourke
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Huang L, Li B, Tang S, Guo H, Li W, Huang X, Yan W, Zou F. Mitochondrial KATP Channels Control Glioma Radioresistance by Regulating ROS-Induced ERK Activation. Mol Neurobiol 2014; 52:626-37. [PMID: 25249341 DOI: 10.1007/s12035-014-8888-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 08/29/2014] [Indexed: 12/01/2022]
Abstract
Malignant glioma is the most prevalent form of malignant brain tumor. Although radiotherapy is widely used in glioma treatment, the radioresistance of glioma cells limits the success of the glioma treatment. The lack of effective targets and signaling pathways to reverse glioma radioresistance is the critical obstacle in successful treatment. In this study, we demonstrate that mitochondrial ATP-sensitive potassium channels (mtK(ATP) channels) are overexpressed in glioma cells and are closely related to the malignancy grade and the overall survival of the patients. Importantly, we showed that mtK(ATP) channels could control glioma radioresistance by regulating reactive oxygen species (ROS)-induced ERK activation. The inhibition of mtK(ATP) channels suppresses glioma radioresistance by inhibiting ERK activation both in vitro and in vivo. These findings reveal the important roles of the mitochondria and mtK(ATP) channels as key regulators in the radioresistance of glioma cells, and suggest that mtK(ATP) channel blockers and MAPK/ERK kinase (MEK) inhibitors are potential targets for drug development of glioma treatments.
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Affiliation(s)
- Lianyan Huang
- Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, China
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79
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Akopova OV, Kolchinskaya LI, Nosar VI, Bouryi VA, Mankovska IN, Sagach VF. Effect of potential-dependent potassium uptake on production of reactive oxygen species in rat brain mitochondria. BIOCHEMISTRY (MOSCOW) 2014; 79:44-53. [PMID: 24512663 DOI: 10.1134/s0006297914010076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effect of potential-dependent potassium uptake on reactive oxygen species (ROS) generation in mitochondria of rat brain was studied. It was found that the effect of K+ uptake on ROS production in the brain mitochondria under steady-state conditions (state 4) was determined by potassium-dependent changes in the membrane potential of the mitochondria (ΔΨm). At K+ concentrations within the range of 0-120 mM, an increase in the initial rate of K(+)-uptake into the matrix resulted in a decrease in the steady-state rate of ROS generation due to the K(+)-induced depolarization of the mitochondrial membrane. The selective blockage of the ATP-dependent potassium channel (K(ATP)(+)-channel) by glibenclamide and 5-hydroxydecanoate resulted in an increase in ROS production due to the membrane repolarization caused by partial inhibition of the potential-dependent K+ uptake. The ATP-dependent transport of K+ was shown to be ~40% of the potential-dependent K+ uptake in the brain mitochondria. Based on the findings of the experiments, the potential-dependent transport of K+ was concluded to be a physiologically important regulator of ROS generation in the brain mitochondria and that the functional activity of the native K(ATP)(+)-channel in these organelles under physiological conditions can be an effective tool for preventing ROS overproduction in brain neurons.
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Affiliation(s)
- O V Akopova
- Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, 01601, Ukraine.
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80
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Agarwal B, Stowe DF, Dash RK, Bosnjak ZJ, Camara AKS. Mitochondrial targets for volatile anesthetics against cardiac ischemia-reperfusion injury. Front Physiol 2014; 5:341. [PMID: 25278902 PMCID: PMC4165278 DOI: 10.3389/fphys.2014.00341] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/20/2014] [Indexed: 12/15/2022] Open
Abstract
Mitochondria are critical modulators of cell function and are increasingly recognized as proximal sensors and effectors that ultimately determine the balance between cell survival and cell death. Volatile anesthetics (VA) are long known for their cardioprotective effects, as demonstrated by improved mitochondrial and cellular functions, and by reduced necrotic and apoptotic cell death during cardiac ischemia and reperfusion (IR) injury. The molecular mechanisms by which VA impart cardioprotection are still poorly understood. Because of the emerging role of mitochondria as therapeutic targets in diseases, including ischemic heart disease, it is important to know if VA-induced cytoprotective mechanisms are mediated at the mitochondrial level. In recent years, considerable evidence points to direct effects of VA on mitochondrial channel/transporter protein functions and electron transport chain (ETC) complexes as potential targets in mediating cardioprotection. This review furnishes an integrated overview of targets that VA impart on mitochondrial channels/transporters and ETC proteins that could provide a basis for cation regulation and homeostasis, mitochondrial bioenergetics, and reactive oxygen species (ROS) emission in redox signaling for cardiac cell protection during IR injury.
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Affiliation(s)
- Bhawana Agarwal
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
| | - David F. Stowe
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
- Department of Physiology, Medical College of WisconsinMilwaukee, WI, USA
- Cardiovascular Research Center, Medical College of WisconsinMilwaukee, WI, USA
- Zablocki VA Medical CenterMilwaukee, WI, USA
- Department of Biomedical Engineering, Marquette UniversityMilwaukee, WI, USA
| | - Ranjan K. Dash
- Department of Physiology, Medical College of WisconsinMilwaukee, WI, USA
- Department of Biomedical Engineering, Marquette UniversityMilwaukee, WI, USA
- Biotechnology and Bioengineering Center, Medical College of WisconsinMilwaukee, WI, USA
| | - Zeljko J. Bosnjak
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
- Department of Physiology, Medical College of WisconsinMilwaukee, WI, USA
- Cardiovascular Research Center, Medical College of WisconsinMilwaukee, WI, USA
| | - Amadou K. S. Camara
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
- Cardiovascular Research Center, Medical College of WisconsinMilwaukee, WI, USA
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81
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Wang TL. Statin (Mevalotin) preconditioning decreases infarct size in senile rat myocardial infarction model. J Acute Med 2014. [DOI: 10.1016/j.jacme.2014.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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82
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Biological networks in ischemic tolerance - rethinking the approach to clinical conditioning. Transl Stroke Res 2014; 4:114-29. [PMID: 24223074 DOI: 10.1007/s12975-012-0244-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The adaptive response (conditioning) to environmental stressors evokes evolutionarily conserved programs in uni- and multicellular organisms that result in increased fitness and resistance to stressor induced injury. Although the concept of conditioning has been around for a while, its translation into clinical therapies targeting neurovascular diseases has only recently begun. The slow pace of clinical adoption might be partially explained by our poor understanding of underpinning mechanisms and of the complex responses of the organism to the stressor. At the 2(nd) Translational Preconditioning Meeting participants engaged in an intense discussion addressing whether the time has come to more aggressively implement clinical conditioning protocols in the treatment of cerebrovascular diseases or whether it would be better to wait until preclinical data would help to minimize clinical empiricism. This review addresses the complex involvement of biological networks in establishing ischemic tolerance at the organism level using two clinically promising conditioning modalities, namely remote ischemic preconditioning, and per- or post-conditioning, as examples.
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83
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O-Uchi J, Ryu SY, Jhun BS, Hurst S, Sheu SS. Mitochondrial ion channels/transporters as sensors and regulators of cellular redox signaling. Antioxid Redox Signal 2014; 21:987-1006. [PMID: 24180309 PMCID: PMC4116125 DOI: 10.1089/ars.2013.5681] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE Mitochondrial ion channels/transporters and the electron transport chain (ETC) serve as key sensors and regulators for cellular redox signaling, the production of reactive oxygen species (ROS) and nitrogen species (RNS) in mitochondria, and balancing cell survival and death. Although the functional and pharmacological characteristics of mitochondrial ion transport mechanisms have been extensively studied for several decades, the majority of the molecular identities that are responsible for these channels/transporters have remained a mystery until very recently. RECENT ADVANCES Recent breakthrough studies uncovered the molecular identities of the diverse array of major mitochondrial ion channels/transporters, including the mitochondrial Ca2+ uniporter pore, mitochondrial permeability transition pore, and mitochondrial ATP-sensitive K+ channel. This new information enables us to form detailed molecular and functional characterizations of mitochondrial ion channels/transporters and their roles in mitochondrial redox signaling. CRITICAL ISSUES Redox-mediated post-translational modifications of mitochondrial ion channels/transporters and ETC serve as key mechanisms for the spatiotemporal control of mitochondrial ROS/RNS generation. FUTURE DIRECTIONS Identification of detailed molecular mechanisms for redox-mediated regulation of mitochondrial ion channels will enable us to find novel therapeutic targets for many diseases that are associated with cellular redox signaling and mitochondrial ion channels/transporters.
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Affiliation(s)
- Jin O-Uchi
- 1 Department of Medicine, Center for Translational Medicine, Jefferson Medical College, Thomas Jefferson University , Philadelphia, Pennsylvania
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84
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Role of mitochondrial permeability transition pore and mitochondrial ATP-sensitive potassium channels in the protective effects of ischemic preconditioning in isolated hearts from fed and fasted rats. J Physiol Biochem 2014; 70:791-800. [DOI: 10.1007/s13105-014-0347-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 07/08/2014] [Indexed: 11/26/2022]
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85
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Augustynek B, Kudin AP, Bednarczyk P, Szewczyk A, Kunz WS. Hemin inhibits the large conductance potassium channel in brain mitochondria: A putative novel mechanism of neurodegeneration. Exp Neurol 2014; 257:70-5. [DOI: 10.1016/j.expneurol.2014.04.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 04/14/2014] [Accepted: 04/23/2014] [Indexed: 02/05/2023]
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86
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Wang JK, Wu HF, Zhou H, Yang B, Liu XZ. Postconditioning with sevoflurane protects against focal cerebral ischemia and reperfusion injury involving mitochondrial ATP-dependent potassium channel and mitochondrial permeability transition pore. Neurol Res 2014; 37:77-83. [PMID: 24965894 DOI: 10.1179/1743132814y.0000000410] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Postconditioning with sevoflurane has been shown to protect against focal cerebral ischemia and reperfusion injury. However, the mechanism remains elusive. In this study, we tested the hypothesis that mitochondrial ATP-sensitive potassium (mitoKATP) and mitochondrial permeability transition pore (mPTP) play roles in the neuroprotection of postconditioning with sevoflurane. METHODS Adult male Sprague-Dawley rats were subjected to MCAO for 90 minutes and then treated with sevoflurane at the beginning of reperfusion. The infarct volume, neurological deficit score, and brain edema were evaluated at 24 hours. Apoptosis were studied by TUNEL. The neuroprotective effect with or without 5-hydroxydecanoate (5-HD), a selective mitoKATP channel blocker or atractyloside (ATR), and an mPTP opener were analyzed. RESULTS Postconditioning with sevoflurane significantly decreased neurological deficit scores, infarct volume, and brain edema and also reduced apoptotic cells. 5-HD and ATR abolished the neuroprotective effect, respectively. 5-HD or ATR alone had no effect on ischemia and reperfusion injury. DISCUSSION Our data suggest that mitoKATP and mPTP play crucial roles in the neuroprotection of postconditioning with sevoflurane.
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87
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Akopova OV, Kolchinskaia LI, Nosar' VI, Buryĭ VA, Man'kovskaia IN, Sagach VF. [The effect of ATP-dependent K(+)-channel opener on transmembrane potassium exchange and reactive oxygen species production upon the opening of mitochondrial pore]. UKRAINIAN BIOCHEMICAL JOURNAL 2014; 86:26-40. [PMID: 24868909 DOI: 10.15407/ubj86.02.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The effect of mitochondrial ATP-dependent K(+)-channel (K(+)ATP-channel) opener diazoxide (DZ) on transmembrane potassium exchange and reactive oxygen species (ROS) formation under the opening of mitochondrial permeability transition pore (MPTP) was studied in rat liver mitochondria. The activation of K(+)-cycling (K(+)-uptake and K(+)/H(+)-exchange) by DZ was established with peak effect at < or = 500 nM. It was shown that MPTP opening as well resulted in the activation of K(+)-cycling together with simultaneous activation of Ca(2+)-cycle in mitochondria. In the absence of depolarization Ca(2+)-cycle is supported by MPTP and Ca(2+)-uniporter. The stimulation of K(+)/H(+)-exchange by MPTP opening led to the activation of K(+)-cycle, but further activation of K(+)/H(+)-exchange resulted in MPTP inhibition. Under the same conditions the decrease in mitochondrial ROS production was observed. It was proposed that the decrease in ROS formation together with K(+)/H(+)-exchange activation could be the constituents of the complex effect of MPTP inhibition induced by K(+)ATP-channel opener.
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88
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Lee GH, Lee HY, Li B, Kim HR, Chae HJ. Bax inhibitor-1-mediated inhibition of mitochondrial Ca2+ intake regulates mitochondrial permeability transition pore opening and cell death. Sci Rep 2014; 4:5194. [PMID: 24899098 PMCID: PMC4046133 DOI: 10.1038/srep05194] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 05/20/2014] [Indexed: 12/13/2022] Open
Abstract
A recently studied endoplasmic reticulum (ER) stress regulator, Bax inhibitor-1 (BI-1) plays a regulatory role in mitochondrial Ca2+ levels. In this study, we identified ER-resident and mitochondria-associated ER membrane (MAM)-resident populations of BI-1. ER stress increased mitochondrial Ca2+ to a lesser extent in BI-1–overexpressing cells (HT1080/BI-1) than in control cells, most likely as a result of impaired mitochondrial Ca2+ intake ability and lower basal levels of intra-ER Ca2+. Moreover, opening of the Ca2+-induced mitochondrial permeability transition pore (PTP) and cytochrome c release were regulated by BI-1. In HT1080/BI-1, the basal mitochondrial membrane potential was low and also resistant to Ca2+ compared with control cells. The activity of the mitochondrial membrane potential-dependent mitochondrial Ca2+ intake pore, the Ca2+ uniporter, was reduced in the presence of BI-1. This study also showed that instead of Ca2+, other cations including K+ enter the mitochondria of HT1080/BI-1 through mitochondrial Ca2+-dependent ion channels, providing a possible mechanism by which mitochondrial Ca2+ intake is reduced, leading to cell protection. We propose a model in which BI-1–mediated sequential regulation of the mitochondrial Ca2+ uniporter and Ca2+-dependent K+ channel opening inhibits mitochondrial Ca2+ intake, thereby inhibiting PTP function and leading to cell protection.
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Affiliation(s)
- Geum-Hwa Lee
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, 561-181, Republic of Korea
| | - Hwa-Young Lee
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, 561-181, Republic of Korea
| | - Bo Li
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, 561-181, Republic of Korea
| | - Hyung-Ryong Kim
- Department of Dental Pharmacology and Wonkwang Dental Research Institute, School of Dentistry, Wonkwang University, Iksan, 570-749, Republic of Korea
| | - Han-Jung Chae
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, 561-181, Republic of Korea
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89
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Yang KC, Bonini MG, Dudley SC. Mitochondria and arrhythmias. Free Radic Biol Med 2014; 71:351-361. [PMID: 24713422 PMCID: PMC4096785 DOI: 10.1016/j.freeradbiomed.2014.03.033] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 03/21/2014] [Accepted: 03/24/2014] [Indexed: 12/31/2022]
Abstract
Mitochondria are essential to providing ATP, thereby satisfying the energy demand of the incessant electrical activity and contractile action of cardiac muscle. Emerging evidence indicates that mitochondrial dysfunction can adversely affect cardiac electrical functioning by impairing the intracellular ion homeostasis and membrane excitability through reduced ATP production and excessive reactive oxygen species (ROS) generation, resulting in increased propensity to cardiac arrhythmias. In this review, the molecular mechanisms linking mitochondrial dysfunction to cardiac arrhythmias are discussed with an emphasis on the impact of increased mitochondrial ROS on the cardiac ion channels and transporters that are critical to maintaining normal electromechanical functioning of the cardiomyocytes. The potential of using mitochondria-targeted antioxidants as a novel antiarrhythmia therapy is highlighted.
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Affiliation(s)
- Kai-Chien Yang
- Lifespan Cardiovascular Institute, Providence VA Medical Center, and Brown University, Providence, RI 02903, USA
| | - Marcelo G Bonini
- Department of Medicine/Cardiology, University of Illinois at Chicago, Chicago, IL 60612, USA; Department of Pathology, and University of Illinois at Chicago, Chicago, IL 60612, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Samuel C Dudley
- Lifespan Cardiovascular Institute, Providence VA Medical Center, and Brown University, Providence, RI 02903, USA.
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90
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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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91
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Akopova OV, Nosar' VI, Kolchinskaia LI, Man'kovskaia IN, Malysheva MK, Sagach VF. [Estimation of ATP-dependent K(+)-channel contribution to potential-dependent potassium uptake in the rat brain mitochondria]. UKRAINIAN BIOCHEMICAL JOURNAL 2014; 86:21-8. [PMID: 24834715 DOI: 10.15407/ubj86.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The effect of potassium on state 4 respiration (substrate oxidation in the absence of ADP) was investigated. It was shown that potential-dependent potassium uptake in the brain mitochondria results in mitochondrial depolarization. Taking into account depolarization effect of potassium, the contribution of the endogenous proton leak as well as K(+)-uptake to the respiration rate was calculated. It was shown that such estimation allows the share of ATP-dependent potassium channel contribution to potential-dependent potassium uptake to be determined by polarographic method.
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92
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93
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The mitochondria as a target for cardioprotection in acute myocardial ischemia. Pharmacol Ther 2014; 142:33-40. [DOI: 10.1016/j.pharmthera.2013.11.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 11/01/2013] [Indexed: 12/28/2022]
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94
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Mitochondrial reactive oxygen species production and elimination. J Mol Cell Cardiol 2014; 73:26-33. [PMID: 24657720 DOI: 10.1016/j.yjmcc.2014.03.011] [Citation(s) in RCA: 213] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 02/24/2014] [Accepted: 03/14/2014] [Indexed: 12/31/2022]
Abstract
Reactive oxygen species (ROS) play an important role in cardiovascular diseases, and one important source for ROS are mitochondria. Emission of ROS from mitochondria is the net result of ROS production at the electron transport chain (ETC) and their elimination by antioxidative enzymes. Both of these processes are highly dependent on the mitochondrial redox state, which is dynamically altered under different physiological and pathological conditions. The concept of "redox-optimized ROS balance" integrates these aspects and implies that oxidative stress occurs when the optimal equilibrium of an intermediate redox state is disturbed towards either strong oxidation or reduction. Furthermore, mitochondria integrate ROS signals from other cellular sources, presumably through a process termed "ROS-induced ROS release" that involves mitochondrial ion channels. Here, we attempt to integrate these recent advances in our understanding of the control of mitochondrial ROS emission and develop a concept of how in heart failure, defects in ion handling can lead to mitochondrial oxidative stress. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System".
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95
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Tsai MS, Huang CH, Tsai CY, Chen HW, Cheng HJ, Hsu CY, Chang WT, Chen WJ. Combination of intravenous ascorbic acid administration and hypothermia after resuscitation improves myocardial function and survival in a ventricular fibrillation cardiac arrest model in the rat. Acad Emerg Med 2014; 21:257-65. [PMID: 24628750 DOI: 10.1111/acem.12335] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 09/03/2013] [Accepted: 09/08/2013] [Indexed: 01/23/2023]
Abstract
OBJECTIVES Intravenous (IV) administration of ascorbic acid during cardiopulmonary resuscitation (CPR) was reported to facilitate defibrillation and improves survival in ventricular fibrillation (VF) cardiac arrest. We investigated whether IV administration of ascorbic acid after return of spontaneous circulation (ROSC) can improve outcomes in VF cardiac arrest in a rat model and its interaction with therapeutic hypothermia. METHODS Ventricular fibrillation-induced cardiac arrest followed by CPR and defibrillation was performed in male Wistar rats. After ROSC, the animals were equally randomized to the normothermia (NormoT), hypothermia (HypoT), ascorbic acid (AA+NormoT), and ascorbic acid plus hypothermia (AA+HypoT) groups. The AA+NormoT and AA+HypoT groups received IV ascorbic acid (100 mg/kg). In the HypoT and AA+HypoT groups, therapeutic hypothermia was maintained at 32°C for 2 hours. RESULTS There were 12 rats in each group. Within 4 hours after ROSC, the HypoT, AA+NormoT, and AA+HypoT groups had significantly lower myocardial lipid peroxidation than the NormoT group. Within 4 hours following ROSC, the AA+NormoT group had a significantly better systolic function (dp/dt40 ) than the NormoT group (6887.9 mm Hg/sec, SD ± 1049.7 mm Hg/sec vs. 5953.6 mm Hg/sec, SD ± 1161.9 mm Hg/sec; p < 0.05). The AA+HypoT group also showed a significantly better diastolic function (-dp/dtmax ) than the HypoT group (dp/dt40 : 8524.8, SD ± 1166.7 mm Hg/sec vs. 7399.8 mm Hg/sec, SD ± 1114.5 mmHg/sec; dp/dtmax : -8183.4 mm Hg/sec, SD ± 1359.0 mm Hg/sec vs. -6573.7 mm Hg/sec, SD ± 1110.9 mm Hg/sec; p < 0.05) at the fourth hour following ROSC. Also at 4 hours, there was less myocytolysis in the HypoT, AA+NormoT, and AA+HypoT groups than the NormoT group. The HypoT, AA+NormoT, and AA+HypoT groups had significantly better survival rates and neurologic outcomes than the NormoT group. Compared with only five surviving animals in the NormoT group, there were nine, eight, and 10 in the HypoT, AA+NormoT, and AA+HypoT groups, respectively, with good neurologic outcomes at 72 hours. CONCLUSIONS Intravenous ascorbic acid administration after ROSC in normothermia may mitigate myocardial damage and improve systolic function, survival rate, and neurologic outcomes in VF cardiac arrest of rat. Combination of ascorbic acid and hypothermia showed an additive effect in improving both systolic and diastolic functions after ROSC.
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Affiliation(s)
- Min-Shan Tsai
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
| | - Chien-Hua Huang
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
| | - Chia-Ying Tsai
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
| | - Huei-Wen Chen
- The Graduate Institute of Toxicology; College of Medicine; National Taiwan University; Taipei Taiwan
| | - Hsaio-Ju Cheng
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
| | - Chiung-Yuan Hsu
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
| | - Wei-Tien Chang
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
| | - Wen-Jone Chen
- The Department of Emergency Medicine; National Taiwan University Medical College and Hospital; Taipei Taiwan
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96
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Tang L, Liu D, Yi X, Xu T, Liu Y, Luo Y, Yin D, He M. The protective effects of puerarin in cardiomyocytes from anoxia/reoxygenation injury are mediated by PKCε. Cell Biochem Funct 2014; 32:378-86. [PMID: 24496955 DOI: 10.1002/cbf.3026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/28/2013] [Accepted: 01/08/2014] [Indexed: 01/25/2023]
Abstract
Puerarin is an isoflavone isolated from traditional Chinese medicine Ge-gen (Radix Puerariae). Clinical studies have confirmed the cardioprotective effects of puerarin; however, the mechanisms underlying these effects are still unclear. On the basis of previous findings, we hypothesized that puerarin protects cardiomyocytes from ischemia-reperfusion injury via the protein kinase C epsilon (PKCε) (a critical cardioprotective protein) signalling pathway. Neonatal rat primary cardiomyocytes were preconditioned with puerarin or puerarin plus εV1-2, a selective PKCε inhibitor, prior to anoxia/reoxygenation (A/R) treatment. Western blot analysis showed that expression and activity of PKCε protein in puerarin preconditioned group were both increased compared with the control or A/R group. Subsequent assays showed that preconditioning with puerarin could increase the viability of neonatal rat primary cardiomyocytes treated with A/R, decreased the generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential, cell necrosis and apoptosis induced by A/R injury. However, the protective effects of puerarin completely disappeared in the group pretreated with puerarin plus εV1-2. Thus, for the first time, we revealed the protective effects of puerarin in cardiomocytes from anoxia/reoxygenation injury are mediated by PKCε.
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Affiliation(s)
- Lei Tang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, PR China; Department of Pharmacology & Molecular Therapeutics, Nanchang University School of Pharmaceutical Science, Nanchang, China
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Ioroi T, Akao M, Iguchi M, Kato M, Kimura T, Izumi Y, Akaike A, Kume T. Serofendic Acid Protects Against Myocardial Ischemia–Reperfusion Injury in Rats. J Pharmacol Sci 2014; 126:274-80. [DOI: 10.1254/jphs.14139fp] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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98
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Zhou L, Solhjoo S, Millare B, Plank G, Abraham MR, Cortassa S, Trayanova N, O'Rourke B. Effects of regional mitochondrial depolarization on electrical propagation: implications for arrhythmogenesis. Circ Arrhythm Electrophysiol 2014; 7:143-51. [PMID: 24382411 DOI: 10.1161/circep.113.000600] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sudden cardiac death often involves arrhythmias triggered by metabolic stress. Loss of mitochondrial function is thought to contribute to the arrhythmogenic substrate, but how mitochondria contribute to uncoordinated electrical activity is poorly understood. It has been proposed that the formation of metabolic current sinks, caused by the nonuniform collapse of mitochondrial inner membrane potential (ΔΨm), contributes to re-entrant arrhythmias because ΔΨm depolarization is tightly coupled to the activation of sarcolemmal ATP-sensitive K(+) channels, hastening action potential repolarization and shortening the refractory period. METHODS AND RESULTS Here, we use computational and experimental methods to investigate how ΔΨm instability can induce re-entrant arrhythmias. We develop the first tissue-level model of cardiac electrical propagation incorporating cellular electrophysiology, excitation-contraction coupling, mitochondrial energetics, and reactive oxygen species balance. Simulations show that re-entry and fibrillation can be initiated by regional ΔΨm loss because of the disparity of refractory periods inside and outside the metabolic sink. Computational results are compared with the effects of a metabolic sink generated experimentally by local perfusion of a mitochondrial uncoupler in a monolayer of cardiac myocytes. CONCLUSIONS The results demonstrate that regional mitochondrial depolarization triggered by oxidative stress activates sarcolemmal ATP-sensitive K(+) currents to form a metabolic sink. Consequent shortening of the action potential inside, but not outside, the sink increases the propensity for re-entry. ΔΨm recovery during pacing can lead to novel mechanisms of ectopic activation. The findings highlight the importance of mitochondria as potential therapeutic targets for sudden death associated with cardiovascular disease.
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Talanov EY, Pavlik LL, Shigaeva MI, Belosludtseva NV, Moshkov DA, Mironova GD. Detection of KIR6 family protein in rat heart and liver mitochondria by immunoelectron microscopy. BIOCHEMISTRY (MOSCOW) SUPPLEMENT SERIES A: MEMBRANE AND CELL BIOLOGY 2014; 8:121-124. [DOI: 10.1134/s1990747813050188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
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Abstract
The sarcolemmal adenosine triphosphate (ATP)-sensitive K(+) (sarcKATP) channel in the heart is a hetero-octamer comprising the pore-forming subunit Kir6.2 and the regulatory subunit sulfonylurea receptor SUR2A. By functional analysis of genetically engineered mice lacking sarcKATP channels, the pathophysiological roles of the K(+) channel in the heart have been extensively evaluated. Although mitochondrial KATP (mitoKATP) channel is proposed to be an important effector for the protection of ischemic myocardium and the inhibition of ischemia/reperfusion-induced ventricular arrhythmias, the molecular identity of mitoKATP channel has not been established. Although selective sarcKATP-channel blockers can prevent ischemia/reperfusion-induced ventricular arrhythmias by inhibiting the action potential shortening in the acute phase, the drugs may aggravate the ischemic damages due to intracellular Ca(2+) overload. The sarcKATP channel is also mandatory for optimal adaptation to hemodynamic stress such as sympathetic activation. Dysfunction of mutated sarcKATP channels in atrial cells may lead to electrical instability and atrial fibrillation. Recently, it has been proposed that the gain-of-function mutation of cardiac Kir6.1 channel can be a pathogenic substrate for J wave syndromes, a cause of idiopathic ventricular fibrillation as early repolarization syndrome or Brugada syndrome, whereas loss of function of the channel mutations can underlie sudden infant death syndrome. However, precise role of Kir6.1 channels in cardiac cells remains to be defined and further study may be needed to clarify the role of Kir6.1 channel in the heart.
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Affiliation(s)
- Haruaki Nakaya
- 1Department of Pharmacology, Chiba University Graduate School of Medicine, Chiba, Japan
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