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Yin XM, Song YY, Jiang WY, Zhang HT, Chen JW, Murao K, Han MX, Sun WP, Zhang GX. Mitochondrial K ATP channel-mediated autophagy contributes to angiotensin II-induced vascular dysfunction in mice. Nutr Metab Cardiovasc Dis 2024; 34:1571-1580. [PMID: 38418351 DOI: 10.1016/j.numecd.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 10/28/2023] [Accepted: 01/15/2024] [Indexed: 03/01/2024]
Abstract
BACKGROUND AND AIM The present study aimed to investigate whether the mitochondrial KATP channel contributes to angiotensin II (Ang II)-induced vascular dysfunction, the development of hypertension, and atherosclerosis. METHODS AND RESULTS ApoE (-/-) mice fed a high-fat diet were chronically infused with Ang II for eight weeks and concomitantly treated with losartan (ARB), apocynin, or 5-hydroxy decanoate (5-HD), or 3-methyladenine (3-MA). Systolic blood pressure was measured, and pathological changes of aortic or liver tissue were observed. Nitric oxide (NO), superoxide dismutase 2 (SOD2) levels and vasorelaxation rate were measured, and protein and mRNA expressions were examined by western blot and RT-PCR. Ang II-induced development of hypertension was suppressed not only by ARB, and apocynin but also by 5-HD or 3-MA. Ang II infusion decreased aortic NO production and relaxation, as well as SOD2 activity in liver, which were improved by all treatments. In addition, Ang II-induced activation of autophagy was suppressed by 5-HD in aortic tissue, furthermore, Ang II increases the atherosclerotic index in plasma and exacerbates the development of atherosclerosis by increases of fat deposition in the aorta and liver. Lipid metabolism-related mRNA expressions (LXR-α, LDLR, SRBI, Acca, and FASN) were changed by Ang II. Similarly, not only ARB, and apocynin, but also 5-HD and 3-MA suppressed Ang II-induced these changes. CONCLUSIONS Our present findings evidence that mitochondrial KATP channel-mediated autophagy contributes to Ang II-induced vascular dysfunction, development of hypertension, and atherosclerosis.
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Affiliation(s)
- Xue-Min Yin
- Department of Physiology, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China
| | - Yi-Yi Song
- Department of Physiology, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China
| | - Wen-Yi Jiang
- Department of Physiology, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China
| | - Hao-Tian Zhang
- Department of Physiology, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China
| | - Jing-Wei Chen
- Department of Internal Medicine, Suzhou TCM Hospital Affiliated to Nanjing University of Chinese Medicine, 18 Yang-Su Road, Suzhou 215003, PR China
| | - Koji Murao
- Department of Endocrine and Metabolism, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe Miki-cho, Kita-gun, Kagawa, 761-0793, Japan
| | - Meng-Xiao Han
- Department of Physiology, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China.
| | - Wan-Ping Sun
- Laboratory of Molecular Diagnostics, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China.
| | - Guo-Xing Zhang
- Department of Physiology, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China; Suzhou Key Laboratory of Drug Research for Prevention and Treatment of Hyperlipidemic Diseases, Medical College of Soochow University, 199 Ren-Ai Road, Dushu Lake Campus, Suzhou Industrial Park, Suzhou 215123, PR China.
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Goel H, Carey M, Elshaikh A, Krinock M, Goyal D, Nadar SK. Cardioprotective and Antianginal Efficacy of Nicorandil: A Comprehensive Review. J Cardiovasc Pharmacol 2023; 82:69-85. [PMID: 37256547 DOI: 10.1097/fjc.0000000000001436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 04/15/2023] [Indexed: 06/01/2023]
Abstract
ABSTRACT Angina pectoris remains a significant burden despite advances in medical therapy and coronary revascularization. Many patients (up to 30%) with angina have normal coronary arteries, with coronary microvascular disease and/or coronary artery vasospasm being major drivers of the myocardial demand-supply mismatch. Even among patients revascularized for symptomatic epicardial coronary stenosis, recurrent angina remains highly prevalent. Medical therapy for angina currently centers around 2 disparate goals, viz secondary prevention of hard clinical outcomes and symptom control. Vasodilators, such as nitrates, have been first-line antianginal agents for decades, along with beta-blockers and calcium channel blockers. However, efficacy in symptoms control is heterogenous, depending on underlying mechanism(s) of angina in an individual patient, often necessitating multiple agents. Nicorandil (NCO) is an antianginal agent first discovered in the late 1970s with a uniquely dual mechanism of action. Like a typical nitrate, it mediates medium-large vessel vasodilation through nitric oxide. In addition, NCO has adenosine triphosphate (ATP)-dependent potassium channel agonist activity (K ATP ), mediating microvascular dilatation. Hence, it has proven effective in both coronary artery vasospasm and coronary microvascular disease, typically challenging patient populations. Moreover, emerging evidence suggests that cardiomyocyte protection against ischemia through ischemic preconditioning may be mediated through K ATP agonism. Finally, there is now fairly firm evidence in favor of NCO in terms of hard event reduction among patients with stable coronary artery disease, following myocardial infarction, and perhaps even among patients with congestive heart failure. This review aims to summarize the mechanism of action of NCO, its efficacy as an antianginal, and current evidence behind its impact on hard outcomes. Finally, we review other cardiac and emerging noncardiac indications for NCO use.
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Affiliation(s)
- Harsh Goel
- Department of Medicine, St Luke's University Hospital, Bethlehem, PA
- Lewis Katz School of Medicine, Temple University, Philadelphia, PA
| | - Matthew Carey
- Department of Medicine, St Luke's University Hospital, Bethlehem, PA
| | | | - Matthew Krinock
- Department of Medicine, St Luke's University Hospital, Bethlehem, PA
- ‡Department of Cardiology, St Luke's University Hospital, Bethlehem, PA
| | - Deepak Goyal
- Department of Cardiology, Worcestershire Acute Hospitals NHS Trust, Worcester, UK; and
| | - Sunil K Nadar
- Department of Cardiology, Dudley Group of Hospitals NHS Trust, Dudley, UK
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3
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Hemingway HW, Richey RE, Moore AM, Olivencia-Yurvati AH, Kline GP, Romero SA. Acute heat exposure protects against endothelial ischemia-reperfusion injury in aged humans. Am J Physiol Regul Integr Comp Physiol 2022; 322:R360-R367. [PMID: 35200050 PMCID: PMC8993535 DOI: 10.1152/ajpregu.00336.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/22/2022] [Accepted: 02/22/2022] [Indexed: 11/22/2022]
Abstract
Nonpharmacological therapies that protect against endothelial ischemia-reperfusion injury (I/R) remain limited in aged adults. Acute heat exposure protects against endothelial I/R injury in young adults, but its efficacy has never been explored in aged adults. Therefore, we tested the hypothesis that acute heat exposure would prevent the attenuation of endothelium-dependent vasodilation after I/R injury in aged adults. Nine (2 men, 69 ± 8 yr) aged adults were exposed to a thermoneutral control condition or whole body passive heating (water-perfused suit) sufficient to increase body core temperature by 1.2°C. Experiments were separated by at least 7 days. Heat exposure was always performed first to time match the thermoneutral control condition. Endothelium-dependent vasodilation was assessed via flow-mediated dilation of the brachial artery before (pre-I/R) and after I/R injury (post-I/R), which was induced by 20 min of arm ischemia followed by 20 min of reperfusion. Flow-mediated dilation was reduced following I/R injury for the thermoneutral control condition (pre-I/R, 4.5 ± 2.9% vs. post-I/R, 0.9 ± 2.8%, P < 0.01), but was well maintained with prior heat exposure (pre-I/R, 4.4 ± 2.8% vs. post-I/R, 3.5 ± 2.8%, P = 0.5). Taken together, acute heat exposure protects against endothelial I/R injury in aged adults. These results highlight the therapeutic potential of heat therapy to prevent endothelial dysfunction associated with I/R injury in aged adults who are most at risk for an ischemic event.
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Affiliation(s)
- Holden W Hemingway
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rauchelle E Richey
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M Moore
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H Olivencia-Yurvati
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
- Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas
| | - Geoffrey P Kline
- Department of Internal Medicine and Geriatrics, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A Romero
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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4
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Hemingway HW, Richey RE, Moore AM, Shokraeifard AM, Thomas GC, Olivencia-Yurvati AH, Romero SA. Shear stress induced by acute heat exposure is not obligatory to protect against endothelial ischemia-reperfusion injury in humans. J Appl Physiol (1985) 2022; 132:199-208. [PMID: 34941435 PMCID: PMC8759960 DOI: 10.1152/japplphysiol.00748.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Acute heat exposure protects against endothelial ischemia-reperfusion (I/R) injury in humans. However, the mechanism/s mediating this protective effect remain unclear. We tested the hypothesis that inhibiting the increase in shear stress induced by acute heat exposure would attenuate the protection of endothelial function following I/R injury. Nine (3 women) young healthy participants were studied under three experimental conditions: 1) thermoneutral control; 2) whole body heat exposure to increase body core temperature by 1.2°C; and 3) heat exposure + brachial artery compression to inhibit the temperature-dependent increase in shear stress. Endothelial function was assessed via brachial artery flow-mediated dilatation before (pre-I/R) and after (post-I/R) 20 min of arm ischemia followed by 20 min of reperfusion. Brachial artery shear rate was increased during heat exposure (681 ± 359 s-1), but not for thermoneutral control (140 ± 63 s-1; P < 0.01 vs. heat exposure) nor for heat + brachial artery compression (139 ± 60 s-1; P < 0.01 vs. heat exposure). Ischemia-reperfusion injury reduced flow-mediated dilatation following thermoneutral control (pre-I/R, 5.5 ± 2.9% vs. post-I/R, 3.8 ± 2.9%; P = 0.06), but was protected following heat exposure (pre-I/R, 5.8 ± 2.9% vs. post-I/R, 6.1 ± 2.9%; P = 0.5) and heat + arterial compression (pre-I/R, 4.4 ± 2.8% vs. post-I/R, 5.8 ± 2.8%; P = 0.1). Contrary to our hypothesis, our findings demonstrate that shear stress induced by acute heat exposure is not obligatory to protect against endothelial I/R injury in humans.NEW & NOTEWORTHY Acute heat exposure protects against endothelial ischemia-reperfusion injury in humans. However, the mechanism/s mediating this protective effect remain unclear. We utilized arterial compression to inhibit the temperature-dependent increase in brachial artery blood velocity that occurs during acute heat exposure to isolate the contribution of shear stress to the protection of endothelial function following ischemia-reperfusion injury. Our findings demonstrate that shear stress induced by acute heat exposure is not obligatory to protect against endothelial I/R injury.
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Affiliation(s)
- Holden W. Hemingway
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rauchelle E. Richey
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M. Moore
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Austin M. Shokraeifard
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Gabriel C. Thomas
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H. Olivencia-Yurvati
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas,2Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A. Romero
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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5
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Jarrard CP, Nagel MJ, Stray-Gundersen S, Tanaka H, Lalande S. Hypoxic preconditioning attenuates ischemia-reperfusion injury in young healthy adults. J Appl Physiol (1985) 2021; 130:846-852. [DOI: 10.1152/japplphysiol.00772.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ischemia-reperfusion injury induced by restoration of blood flow following occlusion impairs flow-mediated dilation, a marker of endothelium-dependent vasodilation. In young healthy adults, exposure to intermittent hypoxia, consisting of alternating short bouts of breathing hypoxic and normoxic air, before an ischemia-reperfusion injury significantly attenuated the reduction in flow-mediated dilation. Thus, hypoxic preconditioning represents a potential strategy to mitigate the effect of ischemia-reperfusion injury associated with ischemic events.
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Affiliation(s)
- Caitlin P. Jarrard
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Mercedes J. Nagel
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Sten Stray-Gundersen
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Hirofumi Tanaka
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Sophie Lalande
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
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6
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Giblett JP, Hoole SP. Letter in response to glucagon-like peptide-1 mediates cardioprotection by remote ischaemic conditioning. Cardiovasc Res 2019; 113:13. [PMID: 28069699 DOI: 10.1093/cvr/cvw237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joel P Giblett
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK; Division of Cardiovascular Medicine, University of Cambridge, Hills Road, Cambridge, CB2 0QQ, UK.,Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK
| | - Stephen P Hoole
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK; Division of Cardiovascular Medicine, University of Cambridge, Hills Road, Cambridge, CB2 0QQ, UK .,Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK
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7
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Xu Y, Yu Q, Yang J, Yuan F, Zhong Y, Zhou Z, Wang N. Acute Hemodynamic Effects of Remote Ischemic Preconditioning on Coronary Perfusion Pressure and Coronary Collateral Blood Flow in Coronary Heart Disease. ACTA CARDIOLOGICA SINICA 2018; 34:299-306. [PMID: 30065567 PMCID: PMC6066945 DOI: 10.6515/acs.201807_34(4).20180317a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 03/17/2018] [Indexed: 11/23/2022]
Abstract
BACKGROUND The aim of this study was to assess the acute hemodynamic effects of remote ischemic preconditioning (RIPC) on coronary perfusion pressure and coronary collateral blood flow. METHODS A total of 17 patients with coronary heart disease with severe (70%-85%) stenosis in one or two vessels confirmed by angiography were enrolled into this study. They were randomly divided into the RIPC group (9 patients) and the control group (8 patients). Distal pressure of coronary artery stenosis before balloon dilation (non-occlusive pressure, Pn-occl) and distal coronary artery occlusive pressure (Poccl) during balloon dilation occlusion were measured in all patients. The patients in the RIPC group received three cycles of lower limb ischemia-reperfusion preconditioning (5 minutes inflation of a blood pressure cuff, followed by 5 minutes reperfusion). For controls, the cuff was not inflated. After this process, Pn-occl and Poccl were measured again in each patient. RESULTS There were no significant differences in angiographic characteristics between the two groups (all p > 0.05). Troponin I (TNI) levels after percutaneous coronary intervention (PCI) were lower in the RIPC group than in the control group (p = 0.004). In the RIPC group, mean Pn-occl and Poccl were significantly increased after RIPC compared to before RIPC [(72.78 ± 10.10) mmHg vs. (79.67 ± 9.79) mmHg, p = 0.002, (20.89 ± 8.61) mmHg vs. (26.78 ± 10.73) mmHg, p = 0.001, respectively]. CONCLUSIONS RIPC can improve distal coronary perfusion pressure and rapidly increase distal coronary occlusive pressure thereby improving coronary collateral blood flow.
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Affiliation(s)
- Yuansheng Xu
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Qinkai Yu
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Jianmin Yang
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Fang Yuan
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Yigang Zhong
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Zhanlin Zhou
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Ningfu Wang
- Department of Cardiology, The Affiliated Hangzhou Hospital of Nanjing Medical University, Hangzhou First People's Hospital, Hangzhou, 310006, China
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8
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Szeto V, Chen NH, Sun HS, Feng ZP. The role of K ATP channels in cerebral ischemic stroke and diabetes. Acta Pharmacol Sin 2018; 39:683-694. [PMID: 29671418 PMCID: PMC5943906 DOI: 10.1038/aps.2018.10] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/19/2018] [Indexed: 12/18/2022] Open
Abstract
ATP-sensitive potassium (KATP) channels are ubiquitously expressed on the plasma membrane of cells in multiple organs, including the heart, pancreas and brain. KATP channels play important roles in controlling and regulating cellular functions in response to metabolic state, which are inhibited by ATP and activated by Mg-ADP, allowing the cell to couple cellular metabolic state (ATP/ADP ratio) to electrical activity of the cell membrane. KATP channels mediate insulin secretion in pancreatic islet beta cells, and controlling vascular tone. Under pathophysiological conditions, KATP channels play cytoprotective role in cardiac myocytes and neurons during ischemia and/or hypoxia. KATP channel is a hetero-octameric complex, consisting of four pore-forming Kir6.x and four regulatory sulfonylurea receptor SURx subunits. These subunits are differentially expressed in various cell types, thus determining the sensitivity of the cells to specific channel modifiers. Sulfonylurea class of antidiabetic drugs blocks KATP channels, which are neuroprotective in stroke, can be one of the high stoke risk factors for diabetic patients. In this review, we discussed the potential effects of KATP channel blockers when used under pathological conditions related to diabetics and cerebral ischemic stroke.
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Affiliation(s)
- Vivian Szeto
- Departments of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Nai-hong Chen
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Hong-shuo Sun
- Departments of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
- Surgery
- Pharmacology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Zhong-ping Feng
- Departments of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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9
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Ranchoux B, Harvey LD, Ayon RJ, Babicheva A, Bonnet S, Chan SY, Yuan JXJ, Perez VDJ. Endothelial dysfunction in pulmonary arterial hypertension: an evolving landscape (2017 Grover Conference Series). Pulm Circ 2018; 8:2045893217752912. [PMID: 29283043 PMCID: PMC5798691 DOI: 10.1177/2045893217752912] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/18/2017] [Indexed: 02/06/2023] Open
Abstract
Endothelial dysfunction is a major player in the development and progression of vascular pathology in pulmonary arterial hypertension (PAH), a disease associated with small vessel loss and obstructive vasculopathy that leads to increased pulmonary vascular resistance, subsequent right heart failure, and premature death. Over the past ten years, there has been tremendous progress in our understanding of pulmonary endothelial biology as it pertains to the genetic and molecular mechanisms that orchestrate the endothelial response to direct or indirect injury, and how their dysregulation can contribute to the pathogenesis of PAH. As one of the major topics included in the 2017 Grover Conference Series, discussion centered on recent developments in four areas of pulmonary endothelial biology: (1) angiogenesis; (2) endothelial-mesenchymal transition (EndMT); (3) epigenetics; and (4) biology of voltage-gated ion channels. The present review will summarize the content of these discussions and provide a perspective on the most promising aspects of endothelial dysfunction that may be amenable for therapeutic development.
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Affiliation(s)
| | - Lloyd D. Harvey
- University of Pittsburgh Vascular Medicine Institute Division of Cardiology, Pittsburgh, PA, USA
| | - Ramon J. Ayon
- Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, AZ, USA
| | - Aleksandra Babicheva
- Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, AZ, USA
| | | | - Stephen Y. Chan
- University of Pittsburgh Vascular Medicine Institute Division of Cardiology, Pittsburgh, PA, USA
| | - Jason X.-J. Yuan
- Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, AZ, USA
| | - Vinicio de Jesus Perez
- Division of Pulmonary and Critical Care Medicine, Stanford University Medical Center, Stanford, CA, USA
- The Vera Moulton Wall Center for Pulmonary Vascular Medicine, Stanford University Medical Center, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University Medical Center, Stanford, CA, USA
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10
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Zhang LC, Huang Z, Li PB, Nie HJ, Deng BN, Duan RF, Xiao ZH, Peng H, Feng H, Liu W. Diazoxide protects rat vascular endothelial cells against hypoxia and cold-induced damage. Exp Ther Med 2017; 13:3257-3266. [PMID: 28587398 PMCID: PMC5450562 DOI: 10.3892/etm.2017.4437] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 01/26/2017] [Indexed: 02/07/2023] Open
Abstract
The present study aimed to examine the effects of hypoxia and cold on vascular endothelial cells (VECs), as well as the protective ability of novel VECs-protective drugs against these injuries. A rat model simulating exposure to hypoxia and cold at high altitude environments was established. Based on these animal experiments, rat aortic VECs were established as injury models and exposed to hypoxia and/or adrenaline (ADR) in vitro. The results revealed that hypoxia significantly altered the levels of nitric oxide and vascular endothelial growth factor, while the cold temperature significantly increased the release of ADR and noradrenaline. Exposure to hypoxia combined with cold temperature significantly affected all these indices. In vitro experiments demonstrated that hypoxia, ADR (which was used to simulate cold in the animal experiments) and the combination of the two factors resulted in damage to the VECs and endothelial dysfunction. In addition, the results also showed that diazoxide, a highly selective mitoKATP opener, protected VECs against these injuries. In conclusion, hypoxia and cold temperature induced endothelial cell dysfunction and endocrine disorders, respectively. Improving endothelial function using diazoxide may be an effective therapeutic strategy in patients with altitude-associated disorders. However, the potential for clinical application requires further study.
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Affiliation(s)
- Lian-Cheng Zhang
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Zhao Huang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sport, Tianjin 300381, P.R. China
| | - Pei-Bing Li
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Hong-Jing Nie
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Bing-Nan Deng
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Rui-Feng Duan
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Zhong-Hai Xiao
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Hui Peng
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
| | - Hong Feng
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sport, Tianjin 300381, P.R. China
| | - Wei Liu
- Department of Environment and Pharmacy, Tianjin Institute of Health and Environmental Medicine, Tianjin 300050, P.R. China
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Therapeutic Effects of Ischemic-Preconditioned Exosomes in Cardiovascular Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 998:271-281. [PMID: 28936746 DOI: 10.1007/978-981-10-4397-0_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Despite years of researches, cardiovascular disease (CVD) remains the most common cause of death around the world. Lots of studies showed that by pretreating with short nonfatal ischemia in in situ organ or distant organ, one could develop tolerance to the following fatal ischemia. The process is called ischemic preconditioning (IPC). IPC prepare the heart for damage by producing inflammatory signals, miRNA, neuro system stimulation and exosomes. Among them, exosomes have been gaining increasing interest since it is characterized by its capability to carry information and its specific ligand-receptor system. Here we will discuss IPC induced exosomes and its protective effects during ischemic heart disease.
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12
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Alternative Interventions to Prevent Oxidative Damage following Ischemia/Reperfusion. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:7190943. [PMID: 28116037 PMCID: PMC5225393 DOI: 10.1155/2016/7190943] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/23/2016] [Accepted: 10/12/2016] [Indexed: 12/25/2022]
Abstract
Ischemia/reperfusion (I/R) lesions are a phenomenon that occurs in multiple pathological states and results in a series of events that end in irreparable damage that severely affects the recovery and health of patients. The principal therapeutic approaches include preconditioning, postconditioning, and remote ischemic preconditioning, which when used separately do not have a great impact on patient mortality or prognosis. Oxidative stress is known to contribute to the damage caused by I/R; however, there are no pharmacological approaches to limit or prevent this. Here, we explain the relationship between I/R and the oxidative stress process and describe some pharmacological options that may target oxidative stress-states.
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Giblett JP, Axell RG, White PA, Clarke SJ, McCormick L, Read PA, Reinhold J, Brown AJ, O'Sullivan M, West NEJ, Dutka DP, Hoole SP. Glucagon-like peptide-1 derived cardioprotection does not utilize a KATP-channel dependent pathway: mechanistic insights from human supply and demand ischemia studies. Cardiovasc Diabetol 2016; 15:99. [PMID: 27431258 PMCID: PMC4950774 DOI: 10.1186/s12933-016-0416-3] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 06/30/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Glucagon-like peptide-1 (7-36) amide (GLP-1) protects against stunning and cumulative left ventricular dysfunction in humans. The mechanism remains uncertain but GLP-1 may act by opening mitochondrial K-ATP channels in a similar fashion to ischemic conditioning. We investigated whether blockade of K-ATP channels with glibenclamide abrogated the protective effect of GLP-1 in humans. METHODS Thirty-two non-diabetic patients awaiting stenting of the left anterior descending artery (LAD) were allocated into 4 groups (control, glibenclamide, GLP-1, and GLP-1 + glibenclamide). Glibenclamide was given orally prior to the procedure. A left ventricular conductance catheter recorded pressure-volume loops during a 1-min low-pressure balloon occlusion (BO1) of the LAD. GLP-1 or saline was then infused for 30-min followed by a further 1-min balloon occlusion (BO2). In a non-invasive study, 10 non-diabetic patients were randomized to receive two dobutamine stress echocardiograms (DSE) during GLP-1 infusion with or without oral glibenclamide pretreatment. RESULTS GLP-1 prevented stunning even with glibenclamide pretreatment; the Δ % dP/dtmax 30-min post-BO1 normalized to baseline after GLP-1: 0.3 ± 6.8 % (p = 0.02) and GLP-1 + glibenclamide: -0.8 ± 9.0 % (p = 0.04) compared to control: -11.5 ± 10.0 %. GLP-1 also reduced cumulative stunning after BO2: -12.8 ± 10.5 % (p = 0.02) as did GLP-1 + glibenclamide: -14.9 ± 9.2 % (p = 0.02) compared to control: -25.7 ± 9.6 %. Glibenclamide alone was no different to control. Glibenclamide pretreatment did not affect global or regional systolic function after GLP-1 at peak DSE stress (EF 74.6 ± 6.4 vs. 74.0 ± 8.0, p = 0.76) or recovery (EF 61.9 ± 5.7 vs. 61.4 ± 5.6, p = 0.74). CONCLUSIONS Glibenclamide pretreatment does not abrogate the protective effect of GLP-1 in human models of non-lethal myocardial ischemia. Trial registration Clinicaltrials.gov Unique Identifier: NCT02128022.
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Affiliation(s)
- Joel P Giblett
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK.,Department of Cardiovascular Medicine, University of Cambridge, Cambridge, UK
| | - Richard G Axell
- Department of Clinical Engineering, Addenbrooke's Hospital, Cambridge, UK
| | - Paul A White
- Department of Clinical Engineering, Addenbrooke's Hospital, Cambridge, UK
| | - Sophie J Clarke
- Department of Cardiovascular Medicine, University of Cambridge, Cambridge, UK
| | - Liam McCormick
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK
| | - Philip A Read
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK
| | - Johannes Reinhold
- Department of Cardiovascular Medicine, University of Cambridge, Cambridge, UK
| | - Adam J Brown
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK.,Department of Cardiovascular Medicine, University of Cambridge, Cambridge, UK
| | - Michael O'Sullivan
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK
| | - Nick E J West
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK
| | - David P Dutka
- Department of Cardiovascular Medicine, University of Cambridge, Cambridge, UK
| | - Stephen P Hoole
- Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, CB23 3RE, UK.
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Busija DW, Rutkai I, Dutta S, Katakam PV. Role of Mitochondria in Cerebral Vascular Function: Energy Production, Cellular Protection, and Regulation of Vascular Tone. Compr Physiol 2016; 6:1529-48. [PMID: 27347901 DOI: 10.1002/cphy.c150051] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mitochondria not only produce energy in the form of ATP to support the activities of cells comprising the neurovascular unit, but mitochondrial events, such as depolarization and/or ROS release, also initiate signaling events which protect the endothelium and neurons against lethal stresses via pre-/postconditioning as well as promote changes in cerebral vascular tone. Mitochondrial depolarization in vascular smooth muscle (VSM), via pharmacological activation of the ATP-dependent potassium channels on the inner mitochondrial membrane (mitoKATP channels), leads to vasorelaxation through generation of calcium sparks by the sarcoplasmic reticulum and subsequent downstream signaling mechanisms. Increased release of ROS by mitochondria has similar effects. Relaxation of VSM can also be indirectly achieved via actions of nitric oxide (NO) and other vasoactive agents produced by endothelium, perivascular and parenchymal nerves, and astroglia following mitochondrial activation. Additionally, NO production following mitochondrial activation is involved in neuronal preconditioning. Cerebral arteries from female rats have greater mitochondrial mass and respiration and enhanced cerebral arterial dilation to mitochondrial activators. Preexisting chronic conditions such as insulin resistance and/or diabetes impair mitoKATP channel relaxation of cerebral arteries and preconditioning. Surprisingly, mitoKATP channel function after transient ischemia appears to be retained in the endothelium of large cerebral arteries despite generalized cerebral vascular dysfunction. Thus, mitochondrial mechanisms may represent the elusive signaling link between metabolic rate and blood flow as well as mediators of vascular change according to physiological status. Mitochondrial mechanisms are an important, but underutilized target for improving vascular function and decreasing brain injury in stroke patients. © 2016 American Physiological Society. Compr Physiol 6:1529-1548, 2016.
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Affiliation(s)
- David W Busija
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Ibolya Rutkai
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Somhrita Dutta
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Prasad V Katakam
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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The Role of Mitochondrial Reactive Oxygen Species in Cardiovascular Injury and Protective Strategies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:8254942. [PMID: 27200148 PMCID: PMC4856919 DOI: 10.1155/2016/8254942] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 12/14/2022]
Abstract
Ischaemia/reperfusion (I/R) injury of the heart represents a major health burden mainly associated with acute coronary syndromes. While timely coronary reperfusion has become the established routine therapy in patients with ST-elevation myocardial infarction, the restoration of blood flow into the previously ischaemic area is always accompanied by myocardial injury. The central mechanism involved in this phenomenon is represented by the excessive generation of reactive oxygen species (ROS). Besides their harmful role when highly generated during early reperfusion, minimal ROS formation during ischaemia and/or at reperfusion is critical for the redox signaling of cardioprotection. In the past decades, mitochondria have emerged as the major source of ROS as well as a critical target for cardioprotective strategies at reperfusion. Mitochondria dysfunction associated with I/R myocardial injury is further described and ultimately analyzed with respect to its role as source of both deleterious and beneficial ROS. Furthermore, the contribution of ROS in the highly investigated field of conditioning strategies is analyzed. In the end, the vascular sources of mitochondria-derived ROS are briefly reviewed.
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Abstract
KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease.
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Affiliation(s)
- Monique N Foster
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| | - William A Coetzee
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
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Zaitseva II, Berggren PO, Zaitsev SV. Insulinotropic compounds decrease endothelial cell survival. Toxicol In Vitro 2016; 33:1-8. [PMID: 26883446 DOI: 10.1016/j.tiv.2016.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 01/05/2016] [Accepted: 02/10/2016] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Hyperglycemia induces damage of vascular endothelial cells leading to diabetic complications. We investigated the effects of insulinotropic compounds and elevated glucose on endothelial cells in the absence or presence of vascular endothelial growth factor (VEGF). RESULTS Human umbilical vein endothelial cells (HUVECs) were treated with glibenclamide, repaglinide and insulinotropic imidazolines at high glucose concentration in the presence or absence of VEGF and viability, proliferation and nitric oxide production were measured. Hyperglycemia inhibited pro-survival effects of VEGF on endothelial cells. Glibenclamide and repaglinide decreased HUVEC viability at elevated glucose concentration in the absence but not in the presence of VEGF, without affecting HUVEC proliferation. Repaglinide also had some positive influence on HUVEC function elevating NO production in the presence of VEGF. Imidazolines showed different activities on endothelial cell survival. Efaroxan diminished HUVEC viability at elevated glucose concentration in the presence, however not in the absence of VEGF, while RX871024 decreased HUVEC survival regardless of the presence of VEGF. SIGNIFICANCE OF THE STUDY Our data demonstrate an important interplay between the actual insulinotropic compounds, VEGF and ambient glucose concentration affecting the survival of the vascular endothelial cells. Consequently, this interplay needs to be taken into consideration when designing novel oral antidiabetic compounds.
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Affiliation(s)
- Irina I Zaitseva
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Per-Olof Berggren
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Sergei V Zaitsev
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-17176 Stockholm, Sweden; Lomonosov Moscow State University, Belozersky Institute of Physico-chemical Biology, Faculty of Bioengineering and Bioinformatics, Moscow 119992, Russia.
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Módis K, Bos EM, Calzia E, van Goor H, Coletta C, Papapetropoulos A, Hellmich MR, Radermacher P, Bouillaud F, Szabo C. Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part II. Pathophysiological and therapeutic aspects. Br J Pharmacol 2014; 171:2123-46. [PMID: 23991749 DOI: 10.1111/bph.12368] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 07/30/2013] [Accepted: 08/05/2013] [Indexed: 12/15/2022] Open
Abstract
Emerging work demonstrates the dual regulation of mitochondrial function by hydrogen sulfide (H2 S), including, at lower concentrations, a stimulatory effect as an electron donor, and, at higher concentrations, an inhibitory effect on cytochrome C oxidase. In the current article, we overview the pathophysiological and therapeutic aspects of these processes. During cellular hypoxia/acidosis, the inhibitory effect of H2 S on complex IV is enhanced, which may shift the balance of H2 S from protective to deleterious. Several pathophysiological conditions are associated with an overproduction of H2 S (e.g. sepsis), while in other disease states H2 S levels and H2 S bioavailability are reduced and its therapeutic replacement is warranted (e.g. diabetic vascular complications). Moreover, recent studies demonstrate that colorectal cancer cells up-regulate the H2 S-producing enzyme cystathionine β-synthase (CBS), and utilize its product, H2 S, as a metabolic fuel and tumour-cell survival factor; pharmacological CBS inhibition or genetic CBS silencing suppresses cancer cell bioenergetics and suppresses cell proliferation and cell chemotaxis. In the last chapter of the current article, we overview the field of H2 S-induced therapeutic 'suspended animation', a concept in which a temporary pharmacological reduction in cell metabolism is achieved, producing a decreased oxygen demand for the experimental therapy of critical illness and/or organ transplantation.
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Affiliation(s)
- Katalin Módis
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
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Khajuria A, Tay C, Shi J, Zhao H, Ma D. Anesthetics attenuate ischemia–reperfusion induced renal injury: Effects and mechanisms. ACTA ACUST UNITED AC 2014; 52:176-84. [DOI: 10.1016/j.aat.2014.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/01/2014] [Indexed: 12/17/2022]
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Protection of coronary endothelial function during cardiac surgery: potential of targeting endothelial ion channels in cardioprotection. BIOMED RESEARCH INTERNATIONAL 2014; 2014:324364. [PMID: 25126553 PMCID: PMC4122001 DOI: 10.1155/2014/324364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/16/2014] [Indexed: 11/28/2022]
Abstract
Vascular endothelium plays a critical role in the control of blood flow by producing vasoactive factors to regulate vascular tone. Ion channels, in particular, K+ channels and Ca2+-permeable channels in endothelial cells, are essential to the production and function of endothelium-derived vasoactive factors. Impairment of coronary endothelial function occurs in open heart surgery that may result in reduction of coronary blood flow and thus in an inadequate myocardial perfusion. Hyperkalemic exposure and concurrent ischemia-reperfusion during cardioplegic intervention compromise NO and EDHF-mediated function and the impairment involves alterations of K+ channels, that is, KATP and KCa, and Ca2+-permeable TRP channels in endothelial cells. Pharmacological modulation of these channels during ischemia-reperfusion and hyperkalemic exposure show promising results on the preservation of NO and EDHF-mediated endothelial function, which suggests the potential of targeting endothelial K+ and TRP channels for myocardial protection during cardiac surgery.
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Javadov S, Jang S, Agostini B. Crosstalk between mitogen-activated protein kinases and mitochondria in cardiac diseases: therapeutic perspectives. Pharmacol Ther 2014; 144:202-25. [PMID: 24924700 DOI: 10.1016/j.pharmthera.2014.05.013] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/30/2014] [Indexed: 02/07/2023]
Abstract
Cardiovascular diseases cause more mortality and morbidity worldwide than any other diseases. Although many intracellular signaling pathways influence cardiac physiology and pathology, the mitogen-activated protein kinase (MAPK) family has garnered significant attention because of its vast implications in signaling and crosstalk with other signaling networks. The extensively studied MAPKs ERK1/2, p38, JNK, and ERK5, demonstrate unique intracellular signaling mechanisms, responding to a myriad of mitogens and stressors and influencing the signaling of cardiac development, metabolism, performance, and pathogenesis. Definitive relationships between MAPK signaling and cardiac dysfunction remain elusive, despite 30 years of extensive clinical studies and basic research of various animal/cell models, severities of stress, and types of stimuli. Still, several studies have proven the importance of MAPK crosstalk with mitochondria, powerhouses of the cell that provide over 80% of ATP for normal cardiomyocyte function and play a crucial role in cell death. Although many questions remain unanswered, there exists enough evidence to consider the possibility of targeting MAPK-mitochondria interactions in the prevention and treatment of heart disease. The goal of this review is to integrate previous studies into a discussion of MAPKs and MAPK-mitochondria signaling in cardiac diseases, such as myocardial infarction (ischemia), hypertrophy and heart failure. A comprehensive understanding of relevant molecular mechanisms, as well as challenges for studies in this area, will facilitate the development of new pharmacological agents and genetic manipulations for therapy of cardiovascular diseases.
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Affiliation(s)
- Sabzali Javadov
- Department of Physiology, School of Medicine, University of Puerto Rico, PR, USA.
| | - Sehwan Jang
- Department of Physiology, School of Medicine, University of Puerto Rico, PR, USA
| | - Bryan Agostini
- Department of Physiology, School of Medicine, University of Puerto Rico, PR, USA
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Busija DW, Katakam PV. Mitochondrial mechanisms in cerebral vascular control: shared signaling pathways with preconditioning. J Vasc Res 2014; 51:175-89. [PMID: 24862206 PMCID: PMC4149841 DOI: 10.1159/000360765] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 02/19/2014] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial-initiated events protect the neurovascular unit against lethal stress via a process called preconditioning, which independently promotes changes in cerebrovascular tone through shared signaling pathways. Activation of adenosine triphosphate (ATP)-dependent potassium channels on the inner mitochondrial membrane (mitoKATP channels) is a specific and dependable way to induce protection of neurons, astroglia, and cerebral vascular endothelium. Through the opening of mitoKATP channels, mitochondrial depolarization leads to activation of protein kinases and transient increases in cytosolic calcium (Ca(2+)) levels that activate terminal mechanisms that protect the neurovascular unit against lethal stress. The release of reactive oxygen species from mitochondria has similar protective effects. Signaling elements of the preconditioning pathways also are involved in the regulation of vascular tone. Activation of mitoKATP channels in cerebral arteries causes vasodilation, with cell-specific contributions from the endothelium, vascular smooth muscles, and nerves. Preexisting chronic conditions, such as insulin resistance and/or diabetes, prevent preconditioning and impair relaxation to mitochondrial-centered responses in cerebral arteries. Surprisingly, mitochondrial activation after anoxic or ischemic stress appears to protect cerebral vascular endothelium and promotes the restoration of blood flow; therefore, mitochondria may represent an important, but underutilized target in attenuating vascular dysfunction and brain injury in stroke patients.
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Affiliation(s)
- David W Busija
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, La., USA
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Mitochondrial KATP channel involvement in angiotensin II-induced autophagy in vascular smooth muscle cells. Basic Res Cardiol 2014; 109:416. [PMID: 24847907 PMCID: PMC4090747 DOI: 10.1007/s00395-014-0416-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 05/05/2014] [Accepted: 05/07/2014] [Indexed: 02/07/2023]
Abstract
Autophagy has emerged as a powerful process in the response to cellular injury. The present study was designed to investigate signal transduction pathways in angiotensin II (Ang II)-induced autophagy. Rat vascular smooth muscle cells (VSMCs) were stimulated with different doses of Ang II (10(-9)-10(-5) mol/L) for different time periods (6-72 h). Incubation with Ang II increased the production of reactive oxygen species (ROS), increased the LC3-II to LC3-I ratio, increased beclin-1 expression, and decreased SQSTM1/p62 expression in a dose- and time-dependent manner. In addition, Ang II increased autophagosome formation. Increased ROS production induced by Ang II was inhibited by Ang II type 1 receptor (AT1) blockers (Olmesartan and Candesartan, ARB), a NADPH Oxidase inhibitor (apocynin), and mitochondrial KATP channels inhibitor (5-hydroxydecanoate, 5HD). Ang II (10(-7) mol/L, 48 h)-induced increase in the LC3-II to LC3-I ratio, the formation of autophagosomes, expression of beclin-1 and decrease in the expression of SQSTM1/p62 were also inhibited by pretreatment with 3-methyladenine or bafilomycin A1 (inhibitors of autophagy), olmesartan and candesartan (in dose-dependent manners), apocynin, 5HD, and siRNA Atg5. Our results indicate that Ang II increases autophagy levels via activation of AT1 receptor and NADPH oxidase. Mitochondrial KATP channels also play an important role in Ang II-induced autophagy. Our results may provide a new strategy for treatment of cardiovascular diseases with Ang II.
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Abstract
In contrast to their role in cell types with higher energy demands, mitochondria in endothelial cells primarily function in signaling cellular responses to environmental cues. This article provides an overview of key aspects of mitochondrial biology in endothelial cells, including subcellular location, biogenesis, dynamics, autophagy, reactive oxygen species production and signaling, calcium homeostasis, regulated cell death, and heme biosynthesis. In each section, we introduce key concepts and then review studies showing the importance of that mechanism to endothelial control of vasomotor tone, angiogenesis, and/or inflammatory activation. We particularly highlight the small number of clinical and translational studies that have investigated each mechanism in human subjects. Finally, we review interventions that target different aspects of mitochondrial function and their effects on endothelial function. The ultimate goal of such research is the identification of new approaches for therapy. The reviewed studies make it clear that mitochondria are important in endothelial physiology and pathophysiology. A great deal of work will be needed, however, before mitochondria-directed therapies are available for the prevention and treatment of cardiovascular disease.
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Affiliation(s)
- Matthew A Kluge
- Evans Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
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Coetzee WA. Multiplicity of effectors of the cardioprotective agent, diazoxide. Pharmacol Ther 2013; 140:167-75. [PMID: 23792087 DOI: 10.1016/j.pharmthera.2013.06.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 02/02/2023]
Abstract
Diazoxide has been identified over the past 50years to have a number of physiological effects, including lowering the blood pressure and rectifying hypoglycemia. Today it is used clinically to treat these conditions. More recently, another important mode of action emerged: diazoxide has powerful protective properties against cardiac ischemia. The heart has intrinsic protective mechanisms against ischemia injury; one of which is ischemic preconditioning. Diazoxide mimics ischemic preconditioning. The purpose of this treatise is to review the literature in an attempt to identify the many effectors of diazoxide and discuss how they may contribute to diazoxide's cardioprotective properties. Particular emphasis is placed on the concentration ranges in which diazoxide affects its different targets and how this compares with the concentrations commonly used to study cardioprotection. It is concluded that diazoxide may have several potential effectors that may potentially contribute to cardioprotection, including KATP channels in the pancreas, smooth muscle, endothelium, neurons and the mitochondrial inner membrane. Diazoxide may also affect other ion channels and ATPases and may directly regulate mitochondrial energetics. It is possible that the success of diazoxide lies in this promiscuity and that the compound acts to rebalance multiple physiological processes during cardiac ischemia.
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Affiliation(s)
- William A Coetzee
- Department of Pediatrics, NYU School of Medicine, New York, NY 10016, United States; Department of Physiology & Neuroscience, NYU School of Medicine, New York, NY 10016, United States; Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, United States.
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Bednarczyk P, Koziel A, Jarmuszkiewicz W, Szewczyk A. Large-conductance Ca²⁺-activated potassium channel in mitochondria of endothelial EA.hy926 cells. Am J Physiol Heart Circ Physiol 2013; 304:H1415-27. [PMID: 23542921 DOI: 10.1152/ajpheart.00976.2012] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the present study, we describe the existence of a large-conductance Ca²⁺-activated potassium (BKCa) channel in the mitochondria of the human endothelial cell line EA.hy926. A single-channel current was recorded from endothelial mitoplasts (i.e., inner mitochondrial membrane) using the patch-clamp technique in the mitoplast-attached mode. A potassium-selective current was recorded with a mean conductance equal to 270 ± 10 pS in a symmetrical 150/150 mM KCl isotonic solution. The channel activity, which was determined as the open probability, increased with the addition of calcium ions and the potassium channel opener NS1619. Conversely, the activity of the channel was irreversibly blocked by paxilline and iberiotoxin, BKCa channel inhibitors. The open-state probability was found to be voltage dependent. The substances known to modulate BKCa channel activity influenced the bioenergetics of mitochondria isolated from human endothelial EA.hy926 cells. In isolated mitochondria, 100 μM Ca²⁺, 10 μM NS1619, and 0.5 μM NS11021 depolarized the mitochondrial membrane potential and stimulated nonphosphorylating respiration. These effects were blocked by iberiotoxin and paxilline in a potassium-dependent manner. Under phosphorylating conditions, NS1619-induced, iberiotoxin-sensitive uncoupling diverted energy from ATP synthesis during the phosphorylating respiration of the endothelial mitochondria. Immunological analysis with antibodies raised against proteins of the plasma membrane BKCa channel identified a pore-forming α-subunit and an auxiliary β₂-subunit of the channel in the endothelial mitochondrial inner membrane. In conclusion, we show for the first time that the inner mitochondrial membrane in human endothelial EA.hy926 cells contains a large-conductance calcium-dependent potassium channel with properties similar to those of the surface membrane BKCa channel.
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Affiliation(s)
- Piotr Bednarczyk
- Department of Biophysics, Warsaw University of Life Sciences, Warsaw, Poland
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Rakobowchuk M, Parsloe ER, Gibbins SE, Harris E, Birch KM. Prolonged low flow reduces reactive hyperemia and augments low flow mediated constriction in the brachial artery independent of the menstrual cycle. PLoS One 2013; 8:e55385. [PMID: 23393572 PMCID: PMC3564810 DOI: 10.1371/journal.pone.0055385] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/29/2012] [Indexed: 12/03/2022] Open
Abstract
Non-invasive forearm ischemia-reperfusion injury and low flow induced vascular dysfunction models provide methods to evaluate vascular function. The role of oestrogen, an endogenous anti-oxidant on recovery from ischemia-reperfusion injury has not been evaluated nor has the impact of prolonged low flow on vascular function been established. Eight healthy women (33±10 yr) attended the lab during the follicular, ovulatory and mid-luteal phases of their menstrual cycles. After 30 minutes of rest, brachial artery vascular function was assessed by ultrasound measurements of diameter changes during 5 minutes of forearm ischemia and 3 minutes after. Subsequently, a 20-minute forearm ischemia period was completed. Further, vascular function assessments were completed 15, 30 and 45 minutes into recovery. Flow-mediated dilation, low-flow-mediated constriction, and reactive hyperaemia proximal to the area of ischemia were determined. Flow-mediated dilation was reduced at 15 minutes of recovery but recovered at 30 and 45 minutes (PRE: 7.1±1.0%, POST15∶4.5±0.6%, POST30∶5. 5±0.7% POST45∶5.9±0.4%, p<0.01). Conversely, low-flow mediated constriction increased (PRE: −1.3±0.4%, POST15: −3.3±0.6%, POST30: −2.5±0.5% POST45: −1.5±0.12%, p<0.01). Reactive hyperaemia was reduced throughout recovery (p<0.05). Data were unaffected by menstrual phase. Prolonged low flow altered vascular function and may relate as much to increased vasoconstriction as with decreased vasodilation. Reductions in anterograde shear and greater retrograde shear likely modulate the brachial artery response, but the reduced total shear also plays an important role. The data suggest substantial alterations in vascular function proximal to areas of ischemia with potential clinical implications following reperfusion.
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Affiliation(s)
- Mark Rakobowchuk
- Department of Biological Sciences, University of Essex, Colchester, United Kingdom.
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Mennander AA, Shalaby A, Oksala N, Leppänen T, Hämäläinen M, Huovinen S, Zhao F, Moilanen E, Tarkka M. Diazoxide may protect endothelial glycocalyx integrity during coronary artery bypass grafting. SCAND CARDIOVASC J 2012; 46:339-44. [DOI: 10.3109/14017431.2012.717303] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Szabó C, Papapetropoulos A. Hydrogen sulphide and angiogenesis: mechanisms and applications. Br J Pharmacol 2012; 164:853-65. [PMID: 21198548 DOI: 10.1111/j.1476-5381.2010.01191.x] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In vascular tissues, hydrogen sulphide (H(2)S) is mainly produced from L-cysteine by the cystathionine gamma-lyase (CSE) enzyme. Recent studies show that administration of H(2)S to endothelial cells in culture stimulates cell proliferation, migration and tube formation. In addition, administration of H(2)S to chicken chorioallantoic membranes stimulates blood vessel growth and branching. Furthermore, in vivo administration of H(2)S to mice stimulates angiogenesis, as demonstrated in the Matrigel plug assay. Pathways involved in the angiogenic response of H(2)S include the PI-3K/Akt pathway, the mitogen activated protein kinase pathway, as well as ATP-sensitive potassium channels. Indirect evidence also suggests that the recently demonstrated role of H(2)S as an inhibitor of phosphodiesterases may play an additional role in its pro-angiogenic effect. The endogenous role of H(2)S in the angiogenic response has been demonstrated in the chicken chorioallantoic membranes, in endothelial cells in vitro and ex vivo. Importantly, the pro-angiogenic effect of vascular endothelial growth factor (but not of fibroblast growth factor) involves the endogenous production of H(2)S. The pro-angiogenic effects of H(2)S are also apparent in vivo: in a model of hindlimb ischaemia-induced angiogenesis, H(2)S induces a marked pro-angiogenic response; similarly, in a model of coronary ischaemia, H(2)S exerts angiogenic effects. Angiogenesis is crucial in the early stage of wound healing. Accordingly, topical administration of H(2)S promotes wound healing, whereas genetic ablation of CSE attenuates it. Pharmacological modulation of H(2)S-mediated angiogenic pathways may open the door for novel therapeutic approaches.
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Affiliation(s)
- Csaba Szabó
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, 77555-1102, USA.
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Pedersen CM, Barnes G, Schmidt MR, Bøtker HE, Kharbanda RK, Newby DE, Cruden NL. Ischaemia-reperfusion injury impairs tissue plasminogen activator release in man. Eur Heart J 2011; 33:1920-7. [PMID: 21990263 PMCID: PMC3409419 DOI: 10.1093/eurheartj/ehr380] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Ischaemia-reperfusion (IR) injury causes endothelium-dependent vasomotor dysfunction that can be prevented by ischaemic preconditioning. The effects of IR injury and preconditioning on endothelium-dependent tissue plasminogen activator (t-PA) release, an important mediator of endogenous fibrinolysis, remain unknown. METHODS AND RESULTS Ischaemia-reperfusion injury (limb occlusion at 200 mmHg for 20 min) was induced in 22 healthy subjects. In 12 subjects, IR injury was preceded by local or remote ischaemic preconditioning (three 5 min episodes of ipsilateral or contralateral limb occlusion, respectively) or sham in a randomized, cross-over trial. Forearm blood flow (FBF) and endothelial t-PA release were assessed using venous occlusion plethysmography and venous blood sampling during intra-arterial infusion of acetylcholine (5-20 µg/min) or substance P (2-8 pmol/min). Acetylcholine and substance P caused dose-dependent increases in FBF (P<0.05 for all). Substance P caused a dose-dependent increase in t-PA release (P<0.05 for all). Acetylcholine and substanceP-mediated vasodilatation and substanceP-mediated t-PA release were impaired following IR injury (P<0.05 for all). Neither local nor remote ischaemic preconditioning protected against the impairment of substance P-mediated vasodilatation or t-PA release. CONCLUSION Ischaemia-reperfusion injury induced substanceP-mediated, endothelium-dependent vasomotor and fibrinolytic dysfunction in man that could not be prevented by ischaemic preconditioning. CLINICAL TRIAL REGISTRATION INFORMATION Reference number: NCT00789243, URL: http://clinicaltrials.gov/ct2/show/NCT00789243?term=NCT00789243&rank=1.
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Shalaby A, Mennander A, Rinne T, Oksala N, Aanismaa R, Narkilahti S, Paavonen T, Laurikka J, Tarkka M. Aquaporin-7 expression during coronary artery bypass grafting with Diazoxide. SCAND CARDIOVASC J 2011; 45:354-9. [DOI: 10.3109/14017431.2011.583357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Okorie MI, Bhavsar DD, Ridout D, Charakida M, Deanfield JE, Loukogeorgakis SP, MacAllister RJ. Postconditioning protects against human endothelial ischaemia-reperfusion injury via subtype-specific KATP channel activation and is mimicked by inhibition of the mitochondrial permeability transition pore. Eur Heart J 2011; 32:1266-74. [PMID: 21362704 DOI: 10.1093/eurheartj/ehr041] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AIMS Intermittent early reperfusion (ischaemic postconditioning; PostC) reduces ischaemia-reperfusion (IR) injury. Using an in vivo model of endothelial IR injury in humans, we sought to determine the role of K(ATP) channels in PostC and whether inhibition of the mitochondrial permeability transition pore (mPTP) at the onset of reperfusion protected against endothelial IR injury. METHODS AND RESULTS Endothelial function (EF) in healthy volunteers was assessed using vascular ultrasound to measure the percentage increase in the diameter of the brachial artery in response to reactive hyperaemia [flow-mediated dilatation (FMD)]. In resistance vessels, venous occlusion plethysmography was used to measure the dilator response to acetylcholine (ACh) [area under ACh dose-response curve (ACh AUC)]. Measurements were made before and after IR injury. Ischaemic postconditioning consisted of three 10 s cycles of alternating ischaemia and reperfusion in the first minute of reperfusion. Oral glibenclamide and glimepiride were used to determine the role of K(ATP) channel subtypes in PostC. Intra-arterial cyclosporine was used to determine the role of mPTP in endothelial IR injury. Ischaemia-reperfusion reduced EF in the brachial artery (FMD 7.1 ± 0.9% pre-IR, 2.8 ± 0.4% post-IR; P < 0.001) and resistance vessels [ACh AUC (×10(4)) 2.1 ± 0.4 pre-IR, 1.5 ± 0.2 post-IR; P < 0.05]. Ischaemic postconditioning preserved EF in the brachial artery [FMD 6.8 ± 0.9% (P < 0.001 vs. post-IR)] and resistance vessels [ACh AUC (×10(4)) 1.9 ± 0.2 (P < 0.001 vs. post-IR)]. Protection by PostC was abolished by glibenclamide in the brachial artery [FMD 3.3 ± 0.2% (P < 0.001 vs. post-IR + PostC)] and in resistance vessels [ACh AUC (×10(4)) 1.1 ± 0.2 (P < 0.001 vs. post-IR + PostC)], whereas glimepiride had no effect. Cyclosporine preserved EF after IR injury in the resistance vessels [ACh AUC (×10(4)) 1.4 ± 0.2 post-IR vs. 2.2 ± 0.3 post-IR + cyclosporine; P < 0.05]. CONCLUSION Protection by PostC against endothelial IR injury in humans depends on K(ATP) channel activation and is mimicked by inhibition of the mPTP at reperfusion.
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Affiliation(s)
- Michael I Okorie
- Centre for Clinical Pharmacology, University College London, The Rayne Institute, 5 University Street, London, UK.
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Devan AE, Umpierre D, Harrison ML, Lin HF, Tarumi T, Renzi CP, Dhindsa M, Hunter SD, Tanaka H. Endothelial ischemia-reperfusion injury in humans: association with age and habitual exercise. Am J Physiol Heart Circ Physiol 2011; 300:H813-9. [PMID: 21239631 DOI: 10.1152/ajpheart.00845.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Advancing age is a major risk factor for coronary artery disease. Endothelial dysfunction accompanied by increased oxidative stress and inflammation with aging may predispose older arteries to greater ischemia-reperfusion (I/R) injury. Because coronary artery ischemia cannot be induced safely, the effects of age and habitual endurance exercise on endothelial I/R injury have not been determined in humans. Using the brachial artery as a surrogate model of the coronary arteries, endothelial function, assessed by brachial artery flow-mediated dilation (FMD), was measured before and after 20 min of continuous forearm occlusion in young sedentary (n = 10, 24 ± 2 yr) and middle-aged (n = 9, 48 ± 2 yr) sedentary adults to gain insight into the effects of primary aging on endothelial I/R injury. Young (n = 9, 25 ± 1 yr) and middle-aged endurance-trained (n = 9, 50 ± 2 yr) adults were also studied to determine whether habitual exercise provides protection from I/R injury. Fifteen minutes after ischemic injury, FMD decreased significantly by 37% in young sedentary, 35% in young endurance-trained, 68% in middle-aged sedentary, and 50% in middle-aged endurance-trained subjects. FMD returned to baseline levels within 30 min in young sedentary and endurance-trained subjects but remained depressed in middle-aged sedentary and endurance-trained subjects. Circulating markers of antioxidant capacity and inflammation were not related to FMD. In conclusion, advancing age is associated with a greater magnitude and delayed recovery from endothelial I/R injury in humans. Habitual endurance exercise may provide partial protection to the endothelium against this form of I/R injury with advancing age.
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Affiliation(s)
- Allison E Devan
- Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas, USA.
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Rahman IA, Mascaro JG, Steeds RP, Frenneaux MP, Nightingale P, Gosling P, Townsend P, Townend JN, Green D, Bonser RS. Remote ischemic preconditioning in human coronary artery bypass surgery: from promise to disappointment? Circulation 2010; 122:S53-9. [PMID: 20837926 DOI: 10.1161/circulationaha.109.926667] [Citation(s) in RCA: 196] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND We assessed whether remote ischemic preconditioning (RIPC) improves myocardial, renal, and lung protection after on-pump coronary surgery. METHODS AND RESULTS This was a single-center, prospective, randomized (1:1), placebo-controlled trial. Patients, investigators, anesthetists, surgeons, and critical care teams were blinded to group allocation. Subjects received RIPC (or placebo) stimuli (×3 upper limb (or dummy arm), 5-minute cycles of 200 mm Hg cuff inflation/deflation) before aortic clamping. Anesthesia, perfusion, cardioplegia, and surgical techniques were standardized. The primary end point was 48-hour area under the curve (AUC) troponin T (cTnT) release. Secondary end points were 6-hour and peak cTnT, ECG changes, cardiac index, inotrope and vasoconstrictor use, renal dysfunction, and lung injury. Hospital survival was 99.4%. Comparing placebo and RIPC, median (interquartile range) AUC 48-hour cTnT (ng/mL(-1)/48 h(-1)); 28 (19, 39) versus 30 (22, 38), 6-hour cTnT (ng/mL(-1)); 0.93(0.59, 1.35) versus 1.01(0.72, 1.43), peak cTnT (ng/mL(-1)); 1.02 (0.74, 1.44) versus 1.04 (0.78, 1.51), de novo left bundle-branch block (4% versus 0%) and Q waves (5.3% versus 5.5%), serial cardiac indices, intraaortic balloon pump usage (8.5% versus 7.5%), inotrope (39% versus 50%) and vasoconstrictor usage (66% versus 64%) were not different. Dialysis requirement (1.2% versus 3.8%), peak creatinine (median [interquartile range], 1.2 mg/dL(-1) (1.1, 1.4) versus 1.2 (1.0, 1.4)), and AUC urinary albumin-creatinine ratios 69 (40, 112) versus 58 (32, 85) were not different. Intubation times; median (interquartile range), 937 minutes(766, 1402) versus 895(675, 1180), 6-hour; 278 (210, 338) versus 270 (218, 323) and 12-hour pO(2):FiO(2) ratios 255 (195, 323) versus 263 (210, 308) were similar. CONCLUSIONS In contrast to prior smaller studies, RIPC did not reduce troponin release, improve hemodynamics, or enhance renal or lung protection. Clinical Trial Registration-URL: http://www.ukcrn.org.uk. Unique identifier: 4659.
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Affiliation(s)
- Ishtiaq A Rahman
- Department of Cardiothoracic Surgery, University Hospital Birmingham NHS Trust, Edgbaston, Birmingham, UK
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Pre-conditioning with the soluble guanylate cyclase activator Cinaciguat reduces ischaemia-reperfusion injury after cardiopulmonary bypass. Eur J Cardiothorac Surg 2010; 39:248-55. [PMID: 20591683 DOI: 10.1016/j.ejcts.2010.05.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 05/14/2010] [Accepted: 05/20/2010] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Activation of the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) pathway can induce potent cardioprotection-like effects against ischaemia-reperfusion injury and nitro-oxidative stress. We investigated the effects of pharmacological pre-conditioning with Cinaciguat (BAY 58-2667), a novel sGC activator on peroxynitrite-induced endothelial dysfunction in vitro, as well as on myocardial and coronary vascular function during reperfusion in a canine model of cardioplegic arrest and extracorporeal circulation. METHODS Isolated coronary arterial rings exposed to peroxynitrite were investigated for vasomotor function. Vehicle- and Cinaciguat-pre-treated (8.33 μg h(-1) or 25 μg h(-1) intravenous (IV) for 30 min) anaesthetised dogs (n = 6-7 per group) underwent hypothermic cardiopulmonary bypass with 60 min of hypothermic cardioplegic arrest. Left- and right-ventricular end-systolic pressure-volume relationship (ESPVR) was measured by a pressure-volume conductance catheter at baseline and after 60 min of reperfusion. Coronary blood flow, vasodilatation to acetylcholine and myocardial level of adenosine triphosphate were determined. RESULTS Pre-incubation of coronary rings with Cinaciguat improved peroxynitrite-induced endothelial dysfunction. Compared with control, pharmacological pre-conditioning with Cinaciguat (25 μg h(-1)) led to higher myocardial adenosine triphosphate content, to a better recovery of left- and right-ventricular contractility (Δ slope of left ventricular ESPVR given as percent of baseline: 102.4 ± 19.1% vs 56.0 ± 7.1%) and to a higher coronary blood flow (49.6 ± 3.5 ml min(-1) vs 28.0 ± 3.9 ml min(-1)). Endothelium-dependent vasodilatation to acetylcholine was improved in the treatment groups. CONCLUSIONS Pre-conditioning with Cinaciguat improves myocardial and endothelial function after cardiopulmonary bypass with hypothermic cardiac arrest. The observed protective effects imply that pharmacological sGC activation could be a novel therapeutic option in the protection against ischaemia-reperfusion injury in cardiac surgery.
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The role of KATP channels on propofol preconditioning in a cellular model of renal ischemia-reperfusion. Anesth Analg 2009; 109:1486-92. [PMID: 19843786 DOI: 10.1213/ane.0b013e3181b76396] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Propofol (2,6-diisopropylphenol) has been shown to protect several organs, including the kidneys, from ischemia-reperfusion (I-R)-induced injury. Although propofol affects adenosine triphosphate-sensitive potassium (K(ATP)) channels in nonrenal tissues, it is still not clear by which mechanisms propofol protects renal cells from such damage. In this study, we investigated whether propofol induces renal preconditioning through renal K(ATP) channels. METHODS A reversible ATP depletion (antimycin A) followed by restoration of substrate supply in LLC-PK1 cells was used as an in vitro model of renal I-R. Cell viability was assessed by dimethylthiazol-diphenyltetrazol bromide and trypan blue dye exclusion test assays. Apoptosis was evaluated by annexin V-fluorescein isothiocyanate staining by flow cytometry and immunofluorescence. Propofol treatments were initiated at various time intervals: 1 or 24 h before ischemia, only during ischemia, or only during reperfusion. To evaluate the mechanisms of propofol protection, specific K(ATP) channel inhibitors or activators were used in some experiments during propofol pretreatment. RESULTS Propofol attenuated I-R injury on LLC-PK1 cells when present either 1 or 24 h before initiated I-R, and also during the recovery period, but not when added only during ischemia. Propofol pretreatment significantly protected LLC-PK1 from I-R-induced apoptosis. The protective effect of propofol was prevented by glibenclamide (a sarcolemmal ATP-dependent K(+) channel blocker) and decreased by 5-hydroxidecanoic acid (a mitochondrial ATP-dependent K(+) channel blocker), but it was not modified by diazoxide (a selective opener of ATP-sensitive K(+) channel). CONCLUSION Propofol protected cells against apoptosis induced by I-R. This protection was probably due to a preconditioning effect of propofol and was, at least in part, mediated by K(ATP) channels.
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Lucchinetti E, Wacker J, Maurer C, Keel M, Härter L, Zaugg K, Zaugg M. Helium breathing provides modest antiinflammatory, but no endothelial protection against ischemia-reperfusion injury in humans in vivo. Anesth Analg 2009; 109:101-8. [PMID: 19535699 DOI: 10.1213/ane.0b013e3181a27e4b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The noble gas helium is devoid of anesthetic effects, and it elicits cardiac preconditioning. We hypothesized that inhalation of helium provides protection against postocclusive endothelial dysfunction after ischemia-reperfusion of the forearm in humans. METHODS Eight healthy male subjects were enrolled in this study with a crossover design. Each volunteer was randomly exposed to 15 min of forearm ischemia in the presence or absence of helium inhalation. Helium was inhaled at an end-tidal concentration of 50 vol% from 15 min before ischemia until 5 min after the onset of reperfusion ("helium conditioning"). Hyperemic reaction, a marker of nitric oxide bioavailability and endothelial function, was determined at 15 and 30 min of reperfusion on the forearm using venous occlusion plethysmography. Expression of the proinflammatory markers CD11b, ICAM-1, PSGL-1, and L-selectin (CD62L) on leukocytes and P-selectin (CD62P), PSGL-1, and CD42b on platelets were measured by flow cytometry during reperfusion. RESULTS Ischemia-reperfusion consistently reduced the postocclusive endothelium-dependent hyperemic reaction at 15 and 30 min of reperfusion. Periischemic inhalation of helium at 50 vol% did not improve postocclusive hyperemic reaction. Helium decreased expression of the proinflammatory marker CD11b and ICAM-1 on leukocytes and attenuated the expression of the procoagulant markers CD42b and PSGL-1 on platelets. CONCLUSIONS Although inhalation of helium diminished the postischemic inflammatory reaction, our data indicate that human endothelium, which is a component of all vital organs, is not amenable to protection by helium at 50 vol% in vivo. This is in contrast to sevoflurane, which protects human endothelium at low subanesthetic concentrations.
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Affiliation(s)
- Eliana Lucchinetti
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
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Gaskin FS, Kamada K, Yusof M, Durante W, Gross G, Korthuis RJ. AICAR preconditioning prevents postischemic leukocyte rolling and adhesion: role of K(ATP) channels and heme oxygenase. Microcirculation 2009; 16:167-76. [PMID: 19152177 DOI: 10.1080/10739680802355897] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE We previously demonstrated that pharmacologic activation of AMP-activated protein kinase (AMPK) with 5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside (AICAR) 24 hours prior to (AICAR preconditioning; AICAR-PC) ischemia/reperfusion (I/R) prevents postischemic leukocyte-endothelial cell adhesive interactions (LEI) by a mechanism initiated by endothelial nitric oxide synthase (eNOS)-dependent NO production during the period of AICAR-PC. The major aim of this study was to examine the role of ATP-sensitive potassium (K(ATP)) channels and heme oxygenase as mediators of the antiadhesive effects of AICAR-PC during I/R 24 hours later. METHODS Intravital fluorescence microscopy was used to quantify LEI in the small intestine of AICAR-preconditioned C57BL/6J mice treated with K(ATP) channel or heme oxygenase inhibitors during I/R 24 hours after AICAR-PC in separate experiments. RESULTS I/R induced marked increases in LEI relative to sham control mice, proadhesive responses that were prevented by AICAR-PC 24 hours prior to I/R. The effects of AICAR-PC to prevent postischemic LEI were abolished by K(ATP) channel or heme oxygenase inhibition during I/R. DISCUSSION/CONCLUSION Our results indicate that the antiadhesive effects of AICAR-PC are mediated by K(ATP) channel- and heme oxygenase-dependent mechanisms during I/R.
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Affiliation(s)
- F Spencer Gaskin
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, One Hospital Drive, Columbia, MO 65212, USA
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Hoole SP, Khan SN, White PA, Heck PM, Kharbanda RK, Densem CG, Clarke SC, Shapiro LM, Schofield PM, O'Sullivan M, Dutka DP. Remote ischaemic pre-conditioning does not attenuate ischaemic left ventricular dysfunction in humans. Eur J Heart Fail 2009; 11:497-505. [DOI: 10.1093/eurjhf/hfp040] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Stephen P. Hoole
- Department of Cardiovascular Medicine; Addenbrooke's Hospital; ACCI, Level 6, Box 110, Hills Road Cambridge CB23 3RE UK
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Sadia N. Khan
- Department of Cardiovascular Medicine; Addenbrooke's Hospital; ACCI, Level 6, Box 110, Hills Road Cambridge CB23 3RE UK
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Paul A. White
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
- Department of Medical Physics and Clinical Engineering; Addenbrooke's Hospital; Hills Road Cambridge CB2 0QQ UK
| | - Patrick M. Heck
- Department of Cardiovascular Medicine; Addenbrooke's Hospital; ACCI, Level 6, Box 110, Hills Road Cambridge CB23 3RE UK
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Rajesh K. Kharbanda
- Department of Cardiovascular Medicine; Addenbrooke's Hospital; ACCI, Level 6, Box 110, Hills Road Cambridge CB23 3RE UK
| | - Cameron G. Densem
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Sarah C. Clarke
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Leonard M. Shapiro
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Peter M. Schofield
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - Michael O'Sullivan
- Department of Cardiology; Papworth Hospital; Papworth Everard Cambridge CB3 8RE UK
| | - David P. Dutka
- Department of Cardiovascular Medicine; Addenbrooke's Hospital; ACCI, Level 6, Box 110, Hills Road Cambridge CB23 3RE UK
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Hoole SP, Heck PM, Sharples L, Khan SN, Duehmke R, Densem CG, Clarke SC, Shapiro LM, Schofield PM, O'Sullivan M, Dutka DP. Cardiac Remote Ischemic Preconditioning in Coronary Stenting (CRISP Stent) Study: a prospective, randomized control trial. Circulation 2009; 119:820-7. [PMID: 19188504 DOI: 10.1161/circulationaha.108.809723] [Citation(s) in RCA: 338] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Myocyte necrosis as a result of elective percutaneous coronary intervention (PCI) occurs in approximately one third of cases and is associated with subsequent cardiovascular events. This study assessed the ability of remote ischemic preconditioning (IPC) to attenuate cardiac troponin I (cTnI) release after elective PCI. METHODS AND RESULTS Two hundred forty-two consecutive patients undergoing elective PCI with undetectable preprocedural cTnI were recruited. Subjects were randomized to receive remote IPC (induced by three 5-minute inflations of a blood pressure cuff to 200 mm Hg around the upper arm, followed by 5-minute intervals of reperfusion) or control (an uninflated cuff around the arm) before arrival in the catheter laboratory. The primary outcome was cTnI at 24 hours after PCI. Secondary outcomes included renal dysfunction and major adverse cardiac and cerebral event rate at 6 months. The median cTnI at 24 hours after PCI was lower in the remote IPC compared with the control group (0.06 versus 0.16 ng/mL; P=0.040). After remote IPC, cTnI was <0.04 ng/mL in 44 patients (42%) compared with 24 in the control group (24%; P=0.01). Subjects who received remote IPC experienced less chest discomfort (P=0.0006) and ECG ST-segment deviation (P=0.005) than control subjects. At 6 months, the major adverse cardiac and cerebral event rate was lower in the remote IPC group (4 versus 13 events; P=0.018). CONCLUSIONS Remote IPC reduces ischemic chest discomfort during PCI, attenuates procedure-related cTnI release, and appears to reduce subsequent cardiovascular events.
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Affiliation(s)
- Stephen P Hoole
- Department of Cardiology, Papworth Hospital, Papworth Everard, UK
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Hoole SP, Heck PM, White PA, Khan SN, O'Sullivan M, Clarke SC, Dutka DP. Remote ischemic preconditioning stimulus does not reduce microvascular resistance or improve myocardial blood flow in patients undergoing elective percutaneous coronary intervention. Angiology 2008; 60:403-11. [PMID: 19106155 DOI: 10.1177/0003319708328921] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Remote ischemic preconditioning (RIPC) may limit myocardial infarction by improving microvascular function and maintaining myocardial blood flow. We hypothesized that a RIPC stimulus would reduce coronary microvascular resistance and improve coronary blood flow during elective percutaneous coronary intervention (PCI). METHOD We prospectively recruited 54 patients with multi-vessel disease (MVD = 32) or single vessel disease awaiting elective PCI. Patients with MVD had non-target vessel (NTV) index of micro-circulatory resistance (IMR) determined, before and after target vessel (TV) PCI (cardiac RIPC). The effect of arm RIPC on serial microvascular resistance (R(p)) was assessed in patients with single vessel disease. RESULTS TV balloon occlusion did not alter the NTV IMR: 16.5 (12.4) baseline vs. 17.6 (11.6) post cardiac RIPC, P = 0.65 or hyperaemic transit time. Arm RIPC did not alter R( p) in patients with single vessel disease: Rp, mmHg.cm(-1).s( -1): 3.5 (1.9) baseline vs. 4.1 (3.0) post arm RIPC, P = 0.19 and coronary flow velocity remained constant. CONCLUSION RIPC stimuli during elective PCI do not affect coronary microvascular resistance or coronary flow in humans.
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Affiliation(s)
- Stephen P Hoole
- Department of Cardiovascular Medicine, Addenbrooke's Hospital, Hills Rd, Cambridge CB2 0QQ, United Kingdom
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Loukogeorgakis SP, Williams R, Panagiotidou AT, Kolvekar SK, Donald A, Cole TJ, Yellon DM, Deanfield JE, MacAllister RJ. Transient limb ischemia induces remote preconditioning and remote postconditioning in humans by a K(ATP)-channel dependent mechanism. Circulation 2007; 116:1386-95. [PMID: 17724264 DOI: 10.1161/circulationaha.106.653782] [Citation(s) in RCA: 210] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Transient limb ischemia administered before a prolonged ischemic insult has systemic protective effects against ischemia-reperfusion (IR) injury (remote ischemic preconditioning [RIPC]). It has been demonstrated that protection from IR can be achieved by brief periods of ischemia applied at a remote site during an injurious ischemic event (remote postconditioning [RPostC]). Using an in vivo model of endothelial IR injury, we sought to determine whether RPostC occurred in humans and whether it shared mechanistic similarities with RIPC. METHODS AND RESULTS Endothelial function was assessed by flow-mediated dilation before and after IR (20 minutes of arm ischemia followed by reperfusion). RIPC was induced by conditioning cycles of 5 minutes of ischemia and reperfusion on the contralateral arm or leg before IR. For RPostC induction, conditioning cycles were administered during the ischemic phase of IR. Oral glibenclamide was used to determine the dependence of RIPC and RPostC on K(ATP) channels. IR caused a significant reduction in flow-mediated dilation in healthy volunteers (baseline, 9.3+/-1.2% versus post-IR, 3.3+/-0.7%; P<0.0001) and patients with atherosclerosis (baseline, 5.5+/-0.6% versus post-IR, 2.3+/-0.5%; P<0.01). This reduction was prevented by RIPC (post-IR+RIPC: healthy volunteers, 7.2+/-0.5% [P<0.0001 versus post-IR]; patients, 4.5+/-0.3% [P<0.01 versus post-IR]) and RPostC (post-IR+RPostC: 8.0+/-0.5%; P<0.0001 versus post-IR). The protective effects of RIPC and RPostC were blocked by glibenclamide. CONCLUSIONS This study demonstrates for the first time in humans that RPostC can be induced by transient limb ischemia and is as effective as RIPC in preventing endothelial IR injury. RIPC and RPostC share mechanistic similarities, with protection being dependent on K(ATP) channel activation. These results suggest that remote conditioning stimuli could be protective in patients with acute ischemia about to undergo therapeutic reperfusion.
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Affiliation(s)
- Stavros P Loukogeorgakis
- Vascular Physiology Unit, Institute of Child Health, University College London, 34 Great Ormond St, London, WC1N 3JE, UK.
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Mayahi L, Heales S, Owen D, Casas JP, Harris J, MacAllister RJ, Hingorani AD. (6R)-5,6,7,8-tetrahydro-L-biopterin and its stereoisomer prevent ischemia reperfusion injury in human forearm. Arterioscler Thromb Vasc Biol 2007; 27:1334-9. [PMID: 17413035 DOI: 10.1161/atvbaha.107.142257] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE 6R-5,6,7,8-tetrahydro-L-biopterin (6R-BH4) is a cofactor for endothelial nitric oxide synthase but also has antioxidant properties. Its stereo-isomer 6S-5,6,7,8-tetrahydro-L-biopterin (6S-BH4) and structurally similar pterin 6R,S-5,6,7,8-tetrahydro-D-neopterin (NH4) are also antioxidants but have no cofactor function. When endothelial nitric oxide synthase is 6R-BH4-deplete, it synthesizes superoxide rather than nitric oxide. Reduced nitric oxide bioavailability by interaction with reactive oxygen species is implicated in endothelial dysfunction (ED). 6R-BH4 corrects ED in animal models of ischemia reperfusion injury (IRI) and in patients with cardiovascular risks. It is uncertain whether the effect of exogenous 6R-BH4 on ED is through its cofactor or antioxidant action. METHODS AND RESULTS In healthy volunteers, forearm blood flow was measured by venous occlusion plethysmography during intra-arterial infusion of the endothelium-dependent vasodilator acetylcholine, or the endothelium-independent vasodilator glyceryl trinitrate, before and after IRI. IRI reduced plasma total antioxidant status (P=0.03) and impaired vasodilatation to acetylcholine (P=0.01), but not to glyceryl trinitrate (P=0.3). Intra-arterial infusion of 6R-BH4, 6S-BH4 and NH4 at approximately equimolar concentrations prevented IRI. CONCLUSION IRI causes ED associated with increased oxidative stress that is prevented by 6R-BH4, 6S-BH4, and NH4, an effect mediated perhaps by an antioxidant rather than cofactor function. Regardless of mechanism, 6R-BH4, 6S-BH4, or NH4 may reduce tissue injury during clinical IRI syndromes.
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Affiliation(s)
- Lila Mayahi
- Centre for Clinical Pharmacology, BHF laboratories, Department of Medicine, UCL, 5 University Street, London, UK, WC1E 6JJ.
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Abstract
Disturbances in vascular function contribute to the development of several diseases of increasing prevalence and thereby contribute significantly to human mortality and morbidity. Atherosclerosis, diabetes, heart failure, and ischemia with attendant reperfusion injury share many of the same risk factors, among the most important being oxidative stress and alterations in the blood concentrations of compounds that influence oxidative stress, such as oxidized low-density lipoprotein. In this review, we focus on endothelial cells: cells in the frontline against these disturbances. Because ATP supplies in endothelial cells are relatively independent of mitochondrial oxidative pathways, the mitochondria of endothelial cells have been somewhat neglected. However, they are emerging as agents with diverse roles in modulating the dynamics of intracellular calcium and the generation of reactive oxygen species and nitric oxide. The mitochondria may also constitute critical "targets" of oxidative stress, because survival of endothelial cells can be compromised by opening of the mitochondrial permeability transition pore or by mitochondrial pathways of apoptosis. In addition, evidence suggests that endothelial mitochondria may play a "reconnaissance" role. For example, although the exact mechanism remains obscure, endothelial mitochondria may sense levels of oxygen in the blood and relay this information to cardiac myocytes as well as modulating the vasodilatory response mediated by endothelial nitric oxide.
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Affiliation(s)
- Sean M Davidson
- The Hatter Cardiovascular Institute, Department of Medicine, Royal Free and University College Medical School, London, United Kingdom.
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Ishii H, Ichimiya S, Kanashiro M, Amano T, Ogawa Y, Mitsuhashi H, Sakai S, Uetani T, Murakami R, Naruse K, Murohara T, Matsubara T. Effect of intravenous nicorandil and preexisting angina pectoris on short- and long-term outcomes in patients with a first ST-segment elevation acute myocardial infarction. Am J Cardiol 2007; 99:1203-7. [PMID: 17478142 DOI: 10.1016/j.amjcard.2006.12.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 12/13/2006] [Accepted: 12/13/2006] [Indexed: 10/23/2022]
Abstract
Published reports have indicated that prodromal angina before acute myocardial infarction (AMI) is associated with better outcomes and that nicorandil has cardioprotective effects on ischemic hearts. We compared cardioprotective effects of intravenous nicorandil with preconditioning effects by prodromal angina in patients with AMI who underwent percutaneous coronary intervention (PCI). In total, 368 patients with first ST-elevation AMI who underwent PCI were randomly assigned to receive nicorandil 12 mg or a placebo intravenously just before PCI. Subjects were assigned to 1 of 4 groups: 52 patients with prodromal angina were given placebo, 129 patients without prodromal angina were given nicorandil, 56 patients with prodromal angina were given nicorandil, and 131 patients without prodromal angina were given placebo. Coronary microvascular impairment after PCI was prevented at similar frequencies in groups with prodromal angina and groups on nicorandil. Five-year rates for freedom from major cardiac events were similar across groups with prodromal angina given placebo, without prodromal angina given nicorandil, and with prodromal angina given nicorandil (92.3%, 93.8%, and 92.9%, respectively) but were significantly lower in the group without prodromal angina given placebo (80.2%, p = 0.0019, 0.044, and 0.042, respectively). In conclusion, intravenous administration of nicorandil before PCI exerts pharmacologic cardioprotective effects similar to ischemic preconditioning in patients with AMI.
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Affiliation(s)
- Hideki Ishii
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
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Gori T, Di Stolfo G, Sicuro S, Dragoni S, Lisi M, Forconi S, Parker JD. Nitroglycerin protects the endothelium from ischaemia and reperfusion: human mechanistic insight. Br J Clin Pharmacol 2007; 64:145-50. [PMID: 17324239 PMCID: PMC2000627 DOI: 10.1111/j.1365-2125.2007.02864.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS Nitroglycerin (GTN) modulates tissue damage induced by ischaemia and reperfusion (IR) in a mechanism that is similar to ischaemic preconditioning. We set out to study, using a human model of endothelial IR injury, whether GTN-induced endothelial preconditioning is mediated by reactive oxygen species (ROS) formation and/or opening of mitochondrial permeability transition pores (mPTP). METHODS In two double-blind, randomized, parallel studies, a total of 66 volunteers underwent measurement of radial artery endothelium-dependent, flow-mediated dilation (FMD) before and after local IR. Subjects were treated, 24 h before IR, with different drugs in order to test the mechanism of GTN-induced endothelial protection. RESULTS Transdermal GTN (0.6 mg h(-1) for 2 h, administered 24 h before IR) significantly reduced the impairment of FMD caused by IR (placebo group: FMD after IR, 1.3 +/- 0.8%; GTN group: FMD after IR, 5.3 +/- 0.9%, P < 0.01 compared with placebo). This protective effect was lost when vitamin C (2 g i.v. at the time of GTN administration) or ciclosporin (an inhibitor of mPTP, 100 mg 2 h prior to GTN administration) were coadministered (FMD after IR: vit C + GTN group, 2.1 +/- 1.0%; ciclosporin + GTN group, 1.7 +/- 0.8%; both P < 0.05 compared with GTN alone). CONCLUSIONS We demonstrate that GTN protects the endothelium against IR-induced endothelial dysfunction, in an effect similar to delayed ischaemic preconditioning. Using a human model, we provide evidence supporting the concept that this protective effect is mediated by ROS release and mPTP opening upon GTN administration.
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Affiliation(s)
- Tommaso Gori
- Department of Internal, Cardiovascular and Geriatric Medicine, University of Siena, Siena, Italy
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Goswami SK, Maulik N, Das DK. Ischemia-reperfusion and cardioprotection: a delicate balance between reactive oxygen species generation and redox homeostasis. Ann Med 2007; 39:275-89. [PMID: 17558599 DOI: 10.1080/07853890701374677] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Ischemia-reperfusion injury of the myocardium has long been a subject of intense research. Cardiac preconditioning, an associated phenomenon, has also been critically investigated over the past two decades. Although the biochemistry of ischemia-reperfusion and its association with oxidative metabolism has long been established, recent studies have further revealed a more intricate role of a number of reactive oxygen-nitrogen species in those processes. Emerging evidence suggests that an elaborate network of enzymes (and other biomolecules) dedicated to the generation, utilization, and diminution of reactive oxygen-nitrogen species maintains the redox homeostasis in the myocardium, and any perturbation of its status has distinctive effects. It thus appears that while excessive generation of reactive species leads to cellular injury, their regulated generation may cause transient and reversible modifications of cellular proteins leading the transmission of intracellular signals with specific effects. Taken together, generation of reactive oxygen-nitrogen species in the myocardium plays a nodal role in mediating both ischemic injury and cardioprotection.
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Affiliation(s)
- Shyamal K Goswami
- Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, CT 06030-1110, USA
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Kandilci HB, Gümüşel B, Demiryürek AT, Lippton H. Preconditioning modulates pulmonary endothelial dysfunction following ischemia-reperfusion injury in the rat lung: role of potassium channels. Life Sci 2006; 79:2172-8. [PMID: 16919300 DOI: 10.1016/j.lfs.2006.07.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Revised: 07/11/2006] [Accepted: 07/12/2006] [Indexed: 11/24/2022]
Abstract
Ischemic preconditioning (IP) may protect the lung from ischemia-reperfusion (I/R) injury following cardiopulmonary by-pass and lung or heart transplantation. The present study was undertaken to investigate the role of ATP-dependent potassium channels (K(ATP)) in IP in the isolated buffer-perfused rat lung (IBPR) under conditions of elevated pulmonary vasoconstrictor tone (PVT). Since pulmonary arterial perfusion flow and left atrial pressure were constant, changes in pulmonary arterial pressure (PAP) directly reflect changes in pulmonary vascular resistance (PVR). When compared to control value, the pulmonary vasodilator responses to histamine and acetylcholine (ACh) following 2 h of hypothermic ischemia were significantly attenuated, whereas the pulmonary vasodilator response to sodium nitroprusside (SNP) was not altered. IP in the form of two cycles of 5 min of ischemia and reperfusion applied prior to the two-hour interval of ischemia, prevented the decrease in the pulmonary vasodilator responses to histamine and ACh. Pretreatment with glybenclamide (GLB) or HMR-1098, but not 5-hydroxydecanoic acid (5-HD), prior to IP abolished the protective effect of IP. In contrast, GLB or 5-HD did not significantly alter the pulmonary vasodilator response to histamine without IP pretreatment. The present data demonstrate that IP prevents impairment of endothelium-dependent vasodilator responses in the rat pulmonary vascular bed. The present data further suggest that IP may alter the mediation of the pulmonary vasodilator response to histamine and thereby trigger a mechanism dependent on activation of sarcolemmal, and not mitochondrial, K(ATP) channels to preserve endothelial-dependent vasodilator responses and protect against I/R injury in the lung.
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Affiliation(s)
- H Burak Kandilci
- Department of Pharmacology, Hacettepe University, Faculty of Pharmacy, 06100, Sihhiye, Ankara, Turkey
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Date T, Taniguchi I, Inada K, Matsuo S, Miyanaga S, Yamane T, Abe Y, Sugimoto KI, Mochizuki S. Nicorandil Inhibits Serum Starvation-Induced Apoptosis in Vascular Endothelial Cells. J Cardiovasc Pharmacol 2005; 46:721-6. [PMID: 16306793 DOI: 10.1097/01.fjc.0000184466.37951.76] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Impact Of Nicorandil in Angina (IONA) randomized trial showed a significant reduction in coronary events, in patients with stable angina treated with a KATP channel opener, nicorandil. However, the impact of nicorandil on endothelial apoptosis remains to be examined. We tested the hypothesis that nicorandil has anti-apoptotic effects in endothelial cells (ECs). Apoptosis was induced by serum starvation in the culture media in human umbilical vein endothelial cells. We examined the effects of nicorandil on endothelial cell apoptosis. Cell viability after serum starvation was significantly higher in the nicorandil-treated group compared with the control group (81 +/- 8% vs. 63 +/- 3%, P < 0.01). Apoptosis, as detected by caspase 3 activation and Hoechst 33258 assay, induced by serum starvation was also effectively abrogated by the treatment of nicorandil (100 muM). The protective effects of nicorandil on endothelial survival were significantly inhibited by a specific mitochondrial KATP channel blocker, 5-Hydroxydecanoic acid. A mitochondrial permeability transition pore activator significantly abolished the anti-apoptotic effect of nicorandil in endothelial cells, indicating that the mechanism of protective effect of nicorandil is involved in the mitochondrial apoptotic pathway although it affects neither Bcl-2 nor Bax protein expression levels. In conclusion, nicorandil inhibits serum starvation-induced endothelial cell apoptosis possibly through mitochondrial KATP channels.
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Affiliation(s)
- Taro Date
- Division of Cardiology, Department of Internal Medicine, Jikei University School of Medicine, Nishi-shinbashi, Tokyo, Japan.
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Gross GJ. Remote preconditioning and delayed cardioprotection in skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2005; 289:R1562-3. [PMID: 16278340 DOI: 10.1152/ajpregu.00627.2005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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