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Wang YX, Reyes-García J, Di Mise A, Zheng YM. Role of ryanodine receptor 2 and FK506-binding protein 12.6 dissociation in pulmonary hypertension. J Gen Physiol 2023; 155:213798. [PMID: 36625865 PMCID: PMC9836826 DOI: 10.1085/jgp.202213100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/29/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Pulmonary hypertension (PH) is a devastating disease characterized by a progressive increase in pulmonary arterial pressure leading to right ventricular failure and death. A major cellular response in this disease is the contraction of smooth muscle cells (SMCs) of the pulmonary vasculature. Cell contraction is determined by the increase in intracellular Ca2+ concentration ([Ca2+]i), which is generated and regulated by various ion channels. Several studies by us and others have shown that ryanodine receptor 2 (RyR2), a Ca2+-releasing channel in the sarcoplasmic reticulum (SR), is an essential ion channel for the control of [Ca2+]i in pulmonary artery SMCs (PASMCs), thereby mediating the sustained vasoconstriction seen in PH. FK506-binding protein 12.6 (FKBP12.6) strongly associates with RyR2 to stabilize its functional activity. FKBP12.6 can be dissociated from RyR2 by a hypoxic stimulus to increase channel function and Ca2+ release, leading to pulmonary vasoconstriction and PH. More specifically, dissociation of the RyR2-FKBP12.6 complex is a consequence of increased mitochondrial ROS generation mediated by the Rieske iron-sulfur protein (RISP) at the mitochondrial complex III after hypoxia. Overall, RyR2/FKBP12.6 dissociation and the corresponding signaling pathway may be an important factor in the development of PH. Novel drugs and biologics targeting RyR2, FKBP12.6, and related molecules may become unique effective therapeutics for PH.
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Affiliation(s)
- Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Correspondence to Yong-Xiao Wang:
| | - Jorge Reyes-García
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México,Ciudad de México, México
| | - Annarita Di Mise
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Yun-Min Zheng:
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2
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Burtscher J, Mallet RT, Pialoux V, Millet GP, Burtscher M. Adaptive Responses to Hypoxia and/or Hyperoxia in Humans. Antioxid Redox Signal 2022; 37:887-912. [PMID: 35102747 DOI: 10.1089/ars.2021.0280] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Significance: Oxygen is indispensable for aerobic life, but its utilization exposes cells and tissues to oxidative stress; thus, tight regulation of cellular, tissue, and systemic oxygen concentrations is crucial. Here, we review the current understanding of how the human organism (mal-)adapts to low (hypoxia) and high (hyperoxia) oxygen levels and how these adaptations may be harnessed as therapeutic or performance enhancing strategies at the systemic level. Recent Advances: Hyperbaric oxygen therapy is already a cornerstone of modern medicine, and the application of mild hypoxia, that is, hypoxia conditioning (HC), to strengthen the resilience of organs or the whole body to severe hypoxic insults is an important preparation for high-altitude sojourns or to protect the cardiovascular system from hypoxic/ischemic damage. Many other applications of adaptations to hypo- and/or hyperoxia are only just emerging. HC-sometimes in combination with hyperoxic interventions-is gaining traction for the treatment of chronic diseases, including numerous neurological disorders, and for performance enhancement. Critical Issues: The dose- and intensity-dependent effects of varying oxygen concentrations render hypoxia- and/or hyperoxia-based interventions potentially highly beneficial, yet hazardous, although the risks versus benefits are as yet ill-defined. Future Directions: The field of low and high oxygen conditioning is expanding rapidly, and novel applications are increasingly recognized, for example, the modulation of aging processes, mood disorders, or metabolic diseases. To advance hypoxia/hyperoxia conditioning to clinical applications, more research on the effects of the intensity, duration, and frequency of altered oxygen concentrations, as well as on individual vulnerabilities to such interventions, is paramount. Antioxid. Redox Signal. 37, 887-912.
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Affiliation(s)
- Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.,Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Vincent Pialoux
- Inter-University Laboratory of Human Movement Biology EA7424, University Claude Bernard Lyon 1, University of Lyon, Lyon, France
| | - Grégoire P Millet
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.,Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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3
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Laban H, Siegmund S, Zappe M, Trogisch FA, Heineke J, Torre CDL, Fisslthaler B, Arnold C, Lauryn J, Büttner M, Mogler C, Kato K, Adams RH, Kuk H, Fischer A, Hecker M, Kuebler WM, Korff T. NFAT5/TonEBP Limits Pulmonary Vascular Resistance in the Hypoxic Lung by Controlling Mitochondrial Reactive Oxygen Species Generation in Arterial Smooth Muscle Cells. Cells 2021; 10:cells10123293. [PMID: 34943801 PMCID: PMC8699676 DOI: 10.3390/cells10123293] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/18/2021] [Accepted: 11/20/2021] [Indexed: 11/16/2022] Open
Abstract
Chronic hypoxia increases the resistance of pulmonary arteries by stimulating their contraction and augmenting their coverage by smooth muscle cells (SMCs). While these responses require adjustment of the vascular SMC transcriptome, regulatory elements are not well defined in this context. Here, we explored the functional role of the transcription factor nuclear factor of activated T-cells 5 (NFAT5/TonEBP) in the hypoxic lung. Regulatory functions of NFAT5 were investigated in cultured artery SMCs and lungs from control (Nfat5fl/fl) and SMC-specific Nfat5-deficient (Nfat5(SMC)−/−) mice. Exposure to hypoxia promoted the expression of genes associated with metabolism and mitochondrial oxidative phosphorylation (OXPHOS) in Nfat5(SMC)−/− versus Nfat5fl/fl lungs. In vitro, hypoxia-exposed Nfat5-deficient pulmonary artery SMCs elevated the level of OXPHOS-related transcripts, mitochondrial respiration, and production of reactive oxygen species (ROS). Right ventricular functions were impaired while pulmonary right ventricular systolic pressure (RVSP) was amplified in hypoxia-exposed Nfat5(SMC)−/− versus Nfat5fl/fl mice. Scavenging of mitochondrial ROS normalized the raise in RVSP. Our findings suggest a critical role for NFAT5 as a suppressor of OXPHOS-associated gene expression, mitochondrial respiration, and ROS production in pulmonary artery SMCs that is vital to limit ROS-dependent arterial resistance in a hypoxic environment.
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Affiliation(s)
- Hebatullah Laban
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany; (H.L.); (S.S.); (M.Z.); (C.A.); (M.H.)
- Deutsches Zentrum für Herz-Kreislauf-Forschung e.V. (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Sophia Siegmund
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany; (H.L.); (S.S.); (M.Z.); (C.A.); (M.H.)
| | - Maren Zappe
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany; (H.L.); (S.S.); (M.Z.); (C.A.); (M.H.)
| | - Felix A. Trogisch
- Department of Cardiovascular Physiology, Mannheim Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany; (F.A.T.); (J.H.)
- European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 69120 Heidelberg, Germany;
| | - Jörg Heineke
- Department of Cardiovascular Physiology, Mannheim Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany; (F.A.T.); (J.H.)
- European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 69120 Heidelberg, Germany;
| | - Carolina De La Torre
- NGS Core Facility, Medical Faculty Mannheim, Heidelberg University, 69120 Heidelberg, Germany;
| | - Beate Fisslthaler
- Institute for Vascular Signalling, Goethe University, Frankfurt am Main, 60323 Frankfurt, Germany;
- German Center of Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt am Main, 60323 Frankfurt, Germany
| | - Caroline Arnold
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany; (H.L.); (S.S.); (M.Z.); (C.A.); (M.H.)
| | - Jonathan Lauryn
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, 10099 Berlin, Germany; (J.L.); (W.M.K.)
| | - Michael Büttner
- Metabolomics Core Technology Platform, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany;
| | - Carolin Mogler
- Institute of Pathology, School of Medicine, Technical University Munich, 80333 Munich, Germany;
| | - Katsuhiro Kato
- Department of Tissue Morphogenesis, Faculty of Medicine, Max Planck Institute for Molecular Biomedicine, University of Münster, 48149 Münster, Germany; (K.K.); (R.H.A.)
| | - Ralf H. Adams
- Department of Tissue Morphogenesis, Faculty of Medicine, Max Planck Institute for Molecular Biomedicine, University of Münster, 48149 Münster, Germany; (K.K.); (R.H.A.)
| | - Hanna Kuk
- The Ottawa Department of Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
| | - Andreas Fischer
- European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 69120 Heidelberg, Germany;
- Division Vascular Signaling and Cancer, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Department of Internal Medicine I, Heidelberg University, 69120 Heidelberg, Germany
| | - Markus Hecker
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany; (H.L.); (S.S.); (M.Z.); (C.A.); (M.H.)
- Deutsches Zentrum für Herz-Kreislauf-Forschung e.V. (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Wolfgang M. Kuebler
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, 10099 Berlin, Germany; (J.L.); (W.M.K.)
| | - Thomas Korff
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany; (H.L.); (S.S.); (M.Z.); (C.A.); (M.H.)
- European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 69120 Heidelberg, Germany;
- Correspondence: ; Tel.: +49-6221-544131; Fax: +49-6221-544038
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Karnati S, Seimetz M, Kleefeldt F, Sonawane A, Madhusudhan T, Bachhuka A, Kosanovic D, Weissmann N, Krüger K, Ergün S. Chronic Obstructive Pulmonary Disease and the Cardiovascular System: Vascular Repair and Regeneration as a Therapeutic Target. Front Cardiovasc Med 2021; 8:649512. [PMID: 33912600 PMCID: PMC8072123 DOI: 10.3389/fcvm.2021.649512] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/08/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD.
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Affiliation(s)
- Srikanth Karnati
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Michael Seimetz
- Excellence Cluster Cardio-Pulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Florian Kleefeldt
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Avinash Sonawane
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Thati Madhusudhan
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
| | - Akash Bachhuka
- UniSA Science, Technology, Engineering and Mathematics, University of South Australia, Mawson Lakes Campus, Adelaide, SA, Australia
| | - Djuro Kosanovic
- Excellence Cluster Cardio-Pulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Norbert Weissmann
- Excellence Cluster Cardio-Pulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Karsten Krüger
- Department of Exercise Physiology and Sports Therapy, University of Giessen, Giessen, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University Würzburg, Würzburg, Germany
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5
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Knock GA. NADPH oxidase in the vasculature: Expression, regulation and signalling pathways; role in normal cardiovascular physiology and its dysregulation in hypertension. Free Radic Biol Med 2019; 145:385-427. [PMID: 31585207 DOI: 10.1016/j.freeradbiomed.2019.09.029] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/29/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023]
Abstract
The last 20-25 years have seen an explosion of interest in the role of NADPH oxidase (NOX) in cardiovascular function and disease. In vascular smooth muscle and endothelium, NOX generates reactive oxygen species (ROS) that act as second messengers, contributing to the control of normal vascular function. NOX activity is altered in response to a variety of stimuli, including G-protein coupled receptor agonists, growth-factors, perfusion pressure, flow and hypoxia. NOX-derived ROS are involved in smooth muscle constriction, endothelium-dependent relaxation and smooth muscle growth, proliferation and migration, thus contributing to the fine-tuning of blood flow, arterial wall thickness and vascular resistance. Through reversible oxidative modification of target proteins, ROS regulate the activity of protein tyrosine phosphatases, kinases, G proteins, ion channels, cytoskeletal proteins and transcription factors. There is now considerable, but somewhat contradictory evidence that NOX contributes to the pathogenesis of hypertension through oxidative stress. Specific NOX isoforms have been implicated in endothelial dysfunction, hyper-contractility and vascular remodelling in various animal models of hypertension, pulmonary hypertension and pulmonary arterial hypertension, but also have potential protective effects, particularly NOX4. This review explores the multiplicity of NOX function in the healthy vasculature and the evidence for and against targeting NOX for antihypertensive therapy.
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Affiliation(s)
- Greg A Knock
- Dpt. of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Life Sciences & Medicine, King's College London, UK.
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6
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Abstract
The pulmonary circulation carries deoxygenated blood from the systemic veins through the pulmonary arteries to be oxygenated in the capillaries that line the walls of the pulmonary alveoli. The pulmonary circulation carries the cardiac output with a relatively low driving pressure, and so differs considerably in structure and function from the systemic circulation to maintain a low-resistance vascular system. The pulmonary circulation is often considered to be a quasi-static system in both experimental and computational studies of pulmonary perfusion and its matching to ventilation (air flow) for exchange. However, the system is highly dynamic, with cardiac output and regional perfusion changing with posture, exercise, and over time. Here we review this dynamic system, with a focus on understanding the physiology of pulmonary vascular dynamics across spatial and temporal scales, and the changes to these dynamics that are reflective of disease. © 2019 American Physiological Society. Compr Physiol 9:1081-1100, 2019.
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Affiliation(s)
- Alys Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Merryn Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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7
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Smith KA, Schumacker PT. Sensors and signals: the role of reactive oxygen species in hypoxic pulmonary vasoconstriction. J Physiol 2018; 597:1033-1043. [PMID: 30091476 DOI: 10.1113/jp275852] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/20/2018] [Indexed: 12/12/2022] Open
Abstract
When lung cells experience hypoxia, the functional response, termed hypoxic pulmonary vasoconstriction, activates a multitude of pathways with the goal of optimizing gas exchange. While previously controversial, overwhelming evidence now suggests that increased reactive oxygen species - produced at complex III of the mitochondrial electron transport chain and released into the intermembrane space - is the cellular oxygen signal responsible for triggering hypoxic pulmonary vasoconstriction. The increased reactive oxygen species (ROS) activate many downstream targets that ultimately lead to increased intracellular ionized calcium concentration and contraction of pulmonary arterial smooth muscle cells. While the specific targets of ROS signals are not completely understood, it is clear that this signalling pathway is critical for development and for normal lung function in newborns and adults.
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Affiliation(s)
- Kimberly A Smith
- Department of Pediatrics, Division of Neonatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Paul T Schumacker
- Department of Pediatrics, Division of Neonatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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Guo X, Fan Y, Cui J, Hao B, Zhu L, Sun X, He J, Yang J, Dong J, Wang Y, Liu X, Chen J. NOX4 expression and distal arteriolar remodeling correlate with pulmonary hypertension in COPD. BMC Pulm Med 2018; 18:111. [PMID: 29986678 PMCID: PMC6038356 DOI: 10.1186/s12890-018-0680-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/25/2018] [Indexed: 12/26/2022] Open
Abstract
Background Pulmonary hypertension (PH) in chronic obstructive pulmonary disease (COPD) is suggested as the consequence of emphysematous destruction of vascular bed and hypoxia of pulmonary microenvironment, mechanisms underpinning its pathogenesis however remain elusive. The dysregulated expression of nicotinamide adenine dinucleotide phosphate (NADPH)-oxidases and superoxide generation by pulmonary vasculatures have significant implications in the hypoxia-induced PH. Methods In this study, the involvement of NADPH oxidase subunit 4 (NOX4) in pulmonary arteriolar remodeling of PH in COPD was investigated by ascertaining the morphological alteration of pulmonary arteries and pulmonary blood flow using cardiac magnetic resonance imaging (cMRI), and the expression and correlation of NOX4 with pulmonary vascular remodeling and pulmonary functions in COPD lungs. Results Results demonstrated that an augmented expression of NOX4 was correlated with the increased volume of pulmonary vascular wall in COPD lung. While the volume of distal pulmonary arteries was inversely correlated with pulmonary functions, despite it was positively associated with the main pulmonary artery distensibility, right ventricular myocardial mass end-systolic and right ventricular myocardial mass end-diastolic in COPD. In addition, an increased malondialdehyde and a decreased superoxide dismutase were observed in sera of COPD patients. Mechanistically, the abundance of NOX4 and production of reactive oxygen species (ROS) in pulmonary artery smooth muscle cells could be dynamically induced by transforming growth factor-beta (TGF-β), which in turn led pulmonary arteriolar remodeling in COPD lungs. Conclusion These results suggest that the NOX4-derived ROS production may play a key role in the development of PH in COPD by promoting distal pulmonary vascular remodeling.
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Affiliation(s)
- Xiaotong Guo
- Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, 804 Shengli South Street, Xingqing District, Yinchuan, Ningxia, 750004, People's Republic of China
| | - Yuchun Fan
- Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, 804 Shengli South Street, Xingqing District, Yinchuan, Ningxia, 750004, People's Republic of China
| | - Jieda Cui
- Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, 804 Shengli South Street, Xingqing District, Yinchuan, Ningxia, 750004, People's Republic of China.,Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Binwei Hao
- Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, 804 Shengli South Street, Xingqing District, Yinchuan, Ningxia, 750004, People's Republic of China
| | - Li Zhu
- Department of Radiology, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Xiao Sun
- Department of Radiology, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Jinxi He
- Department of Thoracic Surgery, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Jiali Yang
- Institute of Human Stem Cell Research, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Jianda Dong
- Department of Pathology, Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Yanyang Wang
- Department of Radiotherapy, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Xiaoming Liu
- Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, 804 Shengli South Street, Xingqing District, Yinchuan, Ningxia, 750004, People's Republic of China. .,Institute of Human Stem Cell Research, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China.
| | - Juan Chen
- Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, 804 Shengli South Street, Xingqing District, Yinchuan, Ningxia, 750004, People's Republic of China.
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9
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Siques P, Brito J, Pena E. Reactive Oxygen Species and Pulmonary Vasculature During Hypobaric Hypoxia. Front Physiol 2018; 9:865. [PMID: 30050455 PMCID: PMC6052911 DOI: 10.3389/fphys.2018.00865] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 06/18/2018] [Indexed: 12/12/2022] Open
Abstract
An increasing number of people are living or working at high altitudes (hypobaric hypoxia) and therefore suffering several physiological, biochemical, and molecular changes. Pulmonary vasculature is one of the main and first responses to hypoxia. These responses imply hypoxic pulmonary vasoconstriction (HPV), remodeling, and eventually pulmonary hypertension (PH). These events occur according to the type and extension of the exposure. There is also increasing evidence that these changes in the pulmonary vascular bed could be mainly attributed to a homeostatic imbalance as a result of increased levels of reactive oxygen species (ROS). The increase in ROS production during hypobaric hypoxia has been attributed to an enhanced activity and expression of nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase), though there is some dispute about which subunit is involved. This enzymatic complex may be directly induced by hypoxia-inducible factor-1α (HIF-1α). ROS has been found to be related to several pathways, cells, enzymes, and molecules in hypoxic pulmonary vasculature responses, from HPV to inflammation, and structural changes, such as remodeling and, ultimately, PH. Therefore, we performed a comprehensive review of the current evidence on the role of ROS in the development of pulmonary vasculature changes under hypoxic conditions, with a focus on hypobaric hypoxia. This review provides information supporting the role of oxidative stress (mainly ROS) in the pulmonary vasculature’s responses under hypobaric hypoxia and depicting possible future therapeutics or research targets. NADPH oxidase-produced oxidative stress is highlighted as a major source of ROS. Moreover, new molecules, such as asymmetric dimethylarginine, and critical inflammatory cells as fibroblasts, could be also involved. Several controversies remain regarding the role of ROS and the mechanisms involved in hypoxic responses that need to be elucidated.
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Affiliation(s)
- Patricia Siques
- Institute of Health Studies, Arturo Prat University, Iquique, Chile
| | - Julio Brito
- Institute of Health Studies, Arturo Prat University, Iquique, Chile
| | - Eduardo Pena
- Institute of Health Studies, Arturo Prat University, Iquique, Chile
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10
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Pak O, Scheibe S, Esfandiary A, Gierhardt M, Sydykov A, Logan A, Fysikopoulos A, Veit F, Hecker M, Kroschel F, Quanz K, Erb A, Schäfer K, Fassbinder M, Alebrahimdehkordi N, Ghofrani HA, Schermuly RT, Brandes RP, Seeger W, Murphy MP, Weissmann N, Sommer N. Impact of the mitochondria-targeted antioxidant MitoQ on hypoxia-induced pulmonary hypertension. Eur Respir J 2018; 51:1701024. [PMID: 29419444 DOI: 10.1183/13993003.01024-2017] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increased mitochondrial reactive oxygen species (ROS), particularly superoxide have been suggested to mediate hypoxic pulmonary vasoconstriction (HPV), chronic hypoxia-induced pulmonary hypertension (PH) and right ventricular (RV) remodelling.We determined ROS in acute, chronic hypoxia and investigated the effect of the mitochondria-targeted antioxidant MitoQ under these conditions.The effect of MitoQ or its inactive carrier substance, decyltriphenylphosphonium (TPP+), on acute HPV (1% O2 for 10 minutes) was investigated in isolated blood-free perfused mouse lungs. Mice exposed for 4 weeks to chronic hypoxia (10% O2) or after banding of the main pulmonary artery (PAB) were treated with MitoQ or TPP+ (50 mg/kg/day).Total cellular superoxide and mitochondrial ROS levels were increased in pulmonary artery smooth muscle cells (PASMC), but decreased in pulmonary fibroblasts in acute hypoxia. MitoQ significantly inhibited HPV and acute hypoxia-induced rise in superoxide concentration. ROS was decreased in PASMC, while it increased in the RV after chronic hypoxia. Correspondingly, MitoQ did not affect the development of chronic hypoxia-induced PH, but attenuated RV remodelling after chronic hypoxia as well as after PAB.Increased mitochondrial ROS of PASMC mediate acute HPV, but not chronic hypoxia-induced PH. MitoQ may be beneficial under conditions of exaggerated acute HPV.
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Affiliation(s)
- Oleg Pak
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Susan Scheibe
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Azadeh Esfandiary
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Mareike Gierhardt
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Akylbek Sydykov
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Angela Logan
- MRC Mitochondrial Biology Unit, CB2 0XY Cambridge, United Kingdom
| | - Athanasios Fysikopoulos
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Florian Veit
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Matthias Hecker
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Florian Kroschel
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Karin Quanz
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Alexandra Erb
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Katharina Schäfer
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Mirja Fassbinder
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Nasim Alebrahimdehkordi
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Hossein A Ghofrani
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Ralph T Schermuly
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Ralf P Brandes
- Institut für Kardiovaskuläre Physiologie, Goethe-Universität, German Center for Cardiovascular Research (DZHK), Partner site RheinMain, 60590 Frankfurt am Main, Germany
| | - Werner Seeger
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, CB2 0XY Cambridge, United Kingdom
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
| | - Natascha Sommer
- Excellence Cluster Cardiopulmonary System, University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Justus-Liebig-University, 35392 Giessen, Germany
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11
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Strielkov I, Pak O, Sommer N, Weissmann N. Recent advances in oxygen sensing and signal transduction in hypoxic pulmonary vasoconstriction. J Appl Physiol (1985) 2017; 123:1647-1656. [PMID: 28751366 DOI: 10.1152/japplphysiol.00103.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a physiological reaction, which adapts lung perfusion to regional ventilation and optimizes gas exchange. Impaired HPV may cause systemic hypoxemia, while generalized HPV contributes to the development of pulmonary hypertension. The triggering mechanisms underlying HPV are still not fully elucidated. Several hypotheses are currently under debate, including a possible decrease as well as an increase in reactive oxygen species as a triggering event. Recent findings suggest an increase in the production of reactive oxygen species in pulmonary artery smooth muscle cells by complex III of the mitochondrial electron transport chain and occurrence of oxygen sensing at complex IV. Other essential components are voltage-dependent potassium and possibly L-type, transient receptor potential channel 6, and transient receptor potential vanilloid 4 channels. The release of arachidonic acid metabolites appears also to be involved in HPV regulation. Further investigation of the HPV mechanisms will facilitate the development of novel therapeutic strategies for the treatment of HPV-related disorders.
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Affiliation(s)
- Ievgen Strielkov
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Oleg Pak
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Natasha Sommer
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
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12
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Nagaraj C, Tabeling C, Nagy BM, Jain PP, Marsh LM, Papp R, Pienn M, Witzenrath M, Ghanim B, Klepetko W, Weir EK, Heschl S, Kwapiszewska G, Olschewski A, Olschewski H. Hypoxic vascular response and ventilation/perfusion matching in end-stage COPD may depend on p22phox. Eur Respir J 2017; 50:50/1/1601651. [PMID: 28729471 DOI: 10.1183/13993003.01651-2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 04/10/2017] [Indexed: 11/05/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease in which the amount of emphysema and airway disease may be very different between individuals, even in end-stage disease. Emphysema formation may be linked to the involvement of the small pulmonary vessels. The NAPDH oxidase (Nox) family is emerging as a key disease-related factor in vascular diseases, but currently its role in hypoxia-induced pulmonary remodelling in COPD remains unclear.Here we investigate the role of p22phox, a regulatory subunit of Nox, in COPD lungs, hypoxic pulmonary vasoconstriction (HPV), hypoxia-induced pulmonary vascular remodelling and pulmonary hypertension.In COPD, compared to control lungs, p22phox expression was significantly reduced. The expression was correlated positively with mean pulmonary arterial pressure and oxygenation index and negatively with the diffusing capacity of the lung for carbon monoxide (p<0.02). This suggests a role of p22phox in ventilation/perfusion ratio matching, vascular remodelling and loss of perfused lung area. In p22phox-/- mice, HPV was significantly impaired. In the chronic hypoxic setting, lack of p22phox was associated with improved right ventricular function and decreased pulmonary vascular remodelling.p22phox-dependent Nox plays an important role in the COPD phenotype, by its action on phase II HPV and chronic vascular remodelling.
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Affiliation(s)
- Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Christoph Tabeling
- Dept of Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Bence M Nagy
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Pritesh P Jain
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Leigh M Marsh
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Rita Papp
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Michael Pienn
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Martin Witzenrath
- Dept of Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Bahil Ghanim
- Dept of Thoracic Surgery, Division of Surgery, Medical University Vienna, Vienna, Austria
| | - Walter Klepetko
- Dept of Thoracic Surgery, Division of Surgery, Medical University Vienna, Vienna, Austria
| | - E Kenneth Weir
- Dept of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Stefan Heschl
- Dept of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria
| | - Grazyna Kwapiszewska
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria .,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Horst Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Division of Pulmonology, Dept of Internal Medicine, Medical University of Graz, Graz, Austria
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13
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Smith KA, Waypa GB, Schumacker PT. Redox signaling during hypoxia in mammalian cells. Redox Biol 2017; 13:228-234. [PMID: 28595160 PMCID: PMC5460738 DOI: 10.1016/j.redox.2017.05.020] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/08/2017] [Accepted: 05/26/2017] [Indexed: 12/18/2022] Open
Abstract
Hypoxia triggers a wide range of protective responses in mammalian cells, which are mediated through transcriptional and post-translational mechanisms. Redox signaling in cells by reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) occurs through the reversible oxidation of cysteine thiol groups, resulting in structural modifications that can change protein function profoundly. Mitochondria are an important source of ROS generation, and studies reveal that superoxide generation by the electron transport chain increases during hypoxia. Other sources of ROS, such as the NAD(P)H oxidases, may also generate oxidant signals in hypoxia. This review considers the growing body of work indicating that increased ROS signals during hypoxia are responsible for regulating the activation of protective mechanisms in diverse cell types.
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Affiliation(s)
- Kimberly A Smith
- Department of Pediatrics, Division of Neonatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Gregory B Waypa
- Department of Pediatrics, Division of Neonatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Paul T Schumacker
- Department of Pediatrics, Division of Neonatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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14
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Song T, Zheng YM, Wang YX. Cross Talk Between Mitochondrial Reactive Oxygen Species and Sarcoplasmic Reticulum Calcium in Pulmonary Arterial Smooth Muscle Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 967:289-298. [DOI: 10.1007/978-3-319-63245-2_17] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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15
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Veith C, Kraut S, Wilhelm J, Sommer N, Quanz K, Seeger W, Brandes RP, Weissmann N, Schröder K. NADPH oxidase 4 is not involved in hypoxia-induced pulmonary hypertension. Pulm Circ 2016; 6:397-400. [PMID: 27683617 DOI: 10.1086/687756] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- C Veith
- Universities of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary System (ECCPS), Giessen, Germany
| | - S Kraut
- UGMLC, member of the DZL, ECCPS, Giessen, Germany
| | - J Wilhelm
- UGMLC, member of the DZL, ECCPS, Giessen, Germany
| | - N Sommer
- UGMLC, member of the DZL, ECCPS, Giessen, Germany
| | - K Quanz
- UGMLC, member of the DZL, ECCPS, Giessen, Germany
| | - W Seeger
- UGMLC, member of the DZL, ECCPS, Giessen, Germany
| | - R P Brandes
- Institute for Cardiovascular Physiology, Goethe University Frankfurt, ECCPS, Frankfurt, Germany
| | - N Weissmann
- UGMLC, member of the DZL, ECCPS, Giessen, Germany
| | - K Schröder
- Institute for Cardiovascular Physiology, Goethe University Frankfurt, ECCPS, Frankfurt, Germany
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16
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Hansen T, Galougahi KK, Celermajer D, Rasko N, Tang O, Bubb KJ, Figtree G. Oxidative and nitrosative signalling in pulmonary arterial hypertension — Implications for development of novel therapies. Pharmacol Ther 2016; 165:50-62. [DOI: 10.1016/j.pharmthera.2016.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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17
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Guo D, Gu J, Jiang H, Ahmed A, Zhang Z, Gu Y. Inhibition of pyruvate kinase M2 by reactive oxygen species contributes to the development of pulmonary arterial hypertension. J Mol Cell Cardiol 2016; 91:179-87. [PMID: 26774701 DOI: 10.1016/j.yjmcc.2016.01.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/28/2015] [Accepted: 01/11/2016] [Indexed: 11/17/2022]
Abstract
AIMS Pulmonary arterial hypertension [1] is a proliferative disorder associated with enhanced proliferation and suppressed apoptosis of pulmonary artery smooth muscle cells (PASMCs). Reactive oxygen species (ROS) is implicated in the development of PAH and regulates the vascular tone and functions. However, which cellular signaling mechanisms are triggered by ROS in PAH is still unknown. Hence, here we wished to characterize the signaling mechanisms triggered by ROS. METHODS AND RESULTS By Western blots, we showed that increased intracellular ROS caused inhibition of the glycolytic pyruvate kinase M2 (PKM2) activity through promoting the phosphorylation of PKM2. Monocrotaline (MCT)-induced rats developed severe PAH and right ventricular hypertrophy, with a significant increase in the P-PKM2 and decrease in pyruvate kinase activity which could be attenuated with the treatments of PKM2 activators, FBP and l-serine. The antioxidant NAC, apocynin and MnTBAP had the similar protective effects in the development of PAH. In vitro assays confirmed that inhibition of PKM2 activity could modulate the flux of glycolytic intermediates in support of cell proliferation through the increased pentose phosphate pathway (PPP). Increased ROS and decreased PKM2 activity also promoted the Cav1.2 expression and intracellular calcium. CONCLUSION Our data provide new evidence that PKM2 makes a critical regulatory contribution to the PAHs for the first time. Decreased pyruvate kinase M2 activity confers additional advantages to rat PASMCs by allowing them to sustain anti-oxidant responses and thereby support cell survival in PAH. It may become a novel treatment strategy in PAH by using of PKM2 activators.
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Affiliation(s)
- Dongqing Guo
- Molecular Pharmacology Laboratory, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Junzhong Gu
- Molecular Pharmacology Laboratory, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Hui Jiang
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproduction, Department of Urology, Peking University Third Hospital, Beijing 100191, China
| | - Asif Ahmed
- Aston Medical School, Aston University, Birmingham B4 7ET, UK
| | - Zhiren Zhang
- Department of Cardiology, The 3(rd) Affiliated Hospital of Harbin Medical University, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China
| | - Yuchun Gu
- Molecular Pharmacology Laboratory, Institute of Molecular Medicine, Peking University, Beijing 100871, China.
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18
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Sommer N, Strielkov I, Pak O, Weissmann N. Oxygen sensing and signal transduction in hypoxic pulmonary vasoconstriction. Eur Respir J 2015; 47:288-303. [PMID: 26493804 DOI: 10.1183/13993003.00945-2015] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/24/2015] [Indexed: 01/17/2023]
Abstract
Hypoxic pulmonary vasoconstriction (HPV), also known as the von Euler-Liljestrand mechanism, is an essential response of the pulmonary vasculature to acute and sustained alveolar hypoxia. During local alveolar hypoxia, HPV matches perfusion to ventilation to maintain optimal arterial oxygenation. In contrast, during global alveolar hypoxia, HPV leads to pulmonary hypertension. The oxygen sensing and signal transduction machinery is located in the pulmonary arterial smooth muscle cells (PASMCs) of the pre-capillary vessels, albeit the physiological response may be modulated in vivo by the endothelium. While factors such as nitric oxide modulate HPV, reactive oxygen species (ROS) have been suggested to act as essential mediators in HPV. ROS may originate from mitochondria and/or NADPH oxidases but the exact oxygen sensing mechanisms, as well as the question of whether increased or decreased ROS cause HPV, are under debate. ROS may induce intracellular calcium increase and subsequent contraction of PASMCs via direct or indirect interactions with protein kinases, phospholipases, sarcoplasmic calcium channels, transient receptor potential channels, voltage-dependent potassium channels and L-type calcium channels, whose relevance may vary under different experimental conditions. Successful identification of factors regulating HPV may allow development of novel therapeutic approaches for conditions of disturbed HPV.
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Affiliation(s)
- Natascha Sommer
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Ievgen Strielkov
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Oleg Pak
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
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19
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NADPH oxidases—do they play a role in TRPC regulation under hypoxia? Pflugers Arch 2015; 468:23-41. [DOI: 10.1007/s00424-015-1731-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/23/2015] [Accepted: 08/25/2015] [Indexed: 12/25/2022]
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20
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Adesina SE, Kang BY, Bijli KM, Ma J, Cheng J, Murphy TC, Michael Hart C, Sutliff RL. Targeting mitochondrial reactive oxygen species to modulate hypoxia-induced pulmonary hypertension. Free Radic Biol Med 2015; 87:36-47. [PMID: 26073127 PMCID: PMC4615392 DOI: 10.1016/j.freeradbiomed.2015.05.042] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 05/08/2015] [Accepted: 05/28/2015] [Indexed: 12/11/2022]
Abstract
Pulmonary hypertension (PH) is characterized by increased pulmonary vascular remodeling, resistance, and pressures. Reactive oxygen species (ROS) contribute to PH-associated vascular dysfunction. NADPH oxidases (Nox) and mitochondria are major sources of superoxide (O(2)(•-)) and hydrogen peroxide (H(2)O(2)) in pulmonary vascular cells. Hypoxia, a common stimulus of PH, increases Nox expression and mitochondrial ROS (mtROS) production. The interactions between these two sources of ROS generation continue to be defined. We hypothesized that mitochondria-derived O(2)(•-) (mtO(2)(•-)) and H(2)O(2) (mtH(2)O(2)) increase Nox expression to promote PH pathogenesis and that mitochondria-targeted antioxidants can reduce mtROS, Nox expression, and hypoxia-induced PH. Exposure of human pulmonary artery endothelial cells to hypoxia for 72 h increased mtO(2)(•-) and mtH(2)O(2). To assess the contribution of mtO(2)(•-) and mtH(2)O(2) to hypoxia-induced PH, mice that overexpress superoxide dismutase 2 (Tg(hSOD2)) or mitochondria-targeted catalase (MCAT) were exposed to normoxia (21% O(2)) or hypoxia (10% O(2)) for three weeks. Compared with hypoxic control mice, MCAT mice developed smaller hypoxia-induced increases in RVSP, α-SMA staining, extracellular H(2)O(2) (Amplex Red), Nox2 and Nox4 (qRT-PCR and Western blot), or cyclinD1 and PCNA (Western blot). In contrast, Tg(hSOD2) mice experienced exacerbated responses to hypoxia. These studies demonstrate that hypoxia increases mtO(2)(•-) and mtH(2)O(2). Targeting mtH(2)O(2) attenuates PH pathogenesis, whereas targeting mtO(2)(•-) exacerbates PH. These differences in PH pathogenesis were mirrored by RVSP, vessel muscularization, levels of Nox2 and Nox4, proliferation, and H(2)O(2) release. These studies suggest that targeted reductions in mtH(2)O(2) generation may be particularly effective in preventing hypoxia-induced PH.
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Affiliation(s)
- Sherry E Adesina
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - Bum-Yong Kang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - Kaiser M Bijli
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - Jing Ma
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - Juan Cheng
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - Tamara C Murphy
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - C Michael Hart
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA
| | - Roy L Sutliff
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, GA 30033, USA.
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21
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Veit F, Pak O, Brandes RP, Weissmann N. Hypoxia-dependent reactive oxygen species signaling in the pulmonary circulation: focus on ion channels. Antioxid Redox Signal 2015; 22:537-52. [PMID: 25545236 PMCID: PMC4322788 DOI: 10.1089/ars.2014.6234] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SIGNIFICANCE An acute lack of oxygen in the lung causes hypoxic pulmonary vasoconstriction, which optimizes gas exchange. In contrast, chronic hypoxia triggers a pathological vascular remodeling causing pulmonary hypertension, and ischemia can cause vascular damage culminating in lung edema. RECENT ADVANCES Regulation of ion channel expression and gating by cellular redox state is a widely accepted mechanism; however, it remains a matter of debate whether an increase or a decrease in reactive oxygen species (ROS) occurs under hypoxic conditions. Ion channel redox regulation has been described in detail for some ion channels, such as Kv channels or TRPC6. However, in general, information on ion channel redox regulation remains scant. CRITICAL ISSUES AND FUTURE DIRECTIONS In addition to the debate of increased versus decreased ROS production during hypoxia, we aim here at describing and deciphering why different oxidants, under different conditions, can cause both activation and inhibition of channel activity. While the upstream pathways affecting channel gating are often well described, we need a better understanding of redox protein modifications to be able to determine the complexity of ion channel redox regulation. Against this background, we summarize the current knowledge on hypoxia-induced ROS-mediated ion channel signaling in the pulmonary circulation.
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Affiliation(s)
- Florian Veit
- 1 Excellence Cluster Cardiopulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), German Center for Lung Research (DZL) , Giessen, Germany
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22
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Pugliese SC, Poth JM, Fini MA, Olschewski A, El Kasmi KC, Stenmark KR. The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes. Am J Physiol Lung Cell Mol Physiol 2014; 308:L229-52. [PMID: 25416383 DOI: 10.1152/ajplung.00238.2014] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop "out-of-proportion" severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines ("second hit") antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.
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Affiliation(s)
- Steven C Pugliese
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado;
| | - Jens M Poth
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Mehdi A Fini
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; and
| | - Karim C El Kasmi
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of Colorado Denver, School of Medicine, Anschutz Medical Campus, Aurora, Colorado
| | - Kurt R Stenmark
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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23
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Pettersen EO, Ebbesen P, Gieling RG, Williams KJ, Dubois L, Lambin P, Ward C, Meehan J, Kunkler IH, Langdon SP, Ree AH, Flatmark K, Lyng H, Calzada MJ, Peso LD, Landazuri MO, Görlach A, Flamm H, Kieninger J, Urban G, Weltin A, Singleton DC, Haider S, Buffa FM, Harris AL, Scozzafava A, Supuran CT, Moser I, Jobst G, Busk M, Toustrup K, Overgaard J, Alsner J, Pouyssegur J, Chiche J, Mazure N, Marchiq I, Parks S, Ahmed A, Ashcroft M, Pastorekova S, Cao Y, Rouschop KM, Wouters BG, Koritzinsky M, Mujcic H, Cojocari D. Targeting tumour hypoxia to prevent cancer metastasis. From biology, biosensing and technology to drug development: the METOXIA consortium. J Enzyme Inhib Med Chem 2014; 30:689-721. [PMID: 25347767 DOI: 10.3109/14756366.2014.966704] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/15/2014] [Indexed: 01/06/2023] Open
Abstract
The hypoxic areas of solid cancers represent a negative prognostic factor irrespective of which treatment modality is chosen for the patient. Still, after almost 80 years of focus on the problems created by hypoxia in solid tumours, we still largely lack methods to deal efficiently with these treatment-resistant cells. The consequences of this lack may be serious for many patients: Not only is there a negative correlation between the hypoxic fraction in tumours and the outcome of radiotherapy as well as many types of chemotherapy, a correlation has been shown between the hypoxic fraction in tumours and cancer metastasis. Thus, on a fundamental basis the great variety of problems related to hypoxia in cancer treatment has to do with the broad range of functions oxygen (and lack of oxygen) have in cells and tissues. Therefore, activation-deactivation of oxygen-regulated cascades related to metabolism or external signalling are important areas for the identification of mechanisms as potential targets for hypoxia-specific treatment. Also the chemistry related to reactive oxygen radicals (ROS) and the biological handling of ROS are part of the problem complex. The problem is further complicated by the great variety in oxygen concentrations found in tissues. For tumour hypoxia to be used as a marker for individualisation of treatment there is a need for non-invasive methods to measure oxygen routinely in patient tumours. A large-scale collaborative EU-financed project 2009-2014 denoted METOXIA has studied all the mentioned aspects of hypoxia with the aim of selecting potential targets for new hypoxia-specific therapy and develop the first stage of tests for this therapy. A new non-invasive PET-imaging method based on the 2-nitroimidazole [(18)F]-HX4 was found to be promising in a clinical trial on NSCLC patients. New preclinical models for testing of the metastatic potential of cells were developed, both in vitro (2D as well as 3D models) and in mice (orthotopic grafting). Low density quantitative real-time polymerase chain reaction (qPCR)-based assays were developed measuring multiple hypoxia-responsive markers in parallel to identify tumour hypoxia-related patterns of gene expression. As possible targets for new therapy two main regulatory cascades were prioritised: The hypoxia-inducible-factor (HIF)-regulated cascades operating at moderate to weak hypoxia (<1% O(2)), and the unfolded protein response (UPR) activated by endoplasmatic reticulum (ER) stress and operating at more severe hypoxia (<0.2%). The prioritised targets were the HIF-regulated proteins carbonic anhydrase IX (CAIX), the lactate transporter MCT4 and the PERK/eIF2α/ATF4-arm of the UPR. The METOXIA project has developed patented compounds targeting CAIX with a preclinical documented effect. Since hypoxia-specific treatments alone are not curative they will have to be combined with traditional anti-cancer therapy to eradicate the aerobic cancer cell population as well.
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Nitric oxide and superoxide anion balance in rats exposed to chronic and long term intermittent hypoxia. BIOMED RESEARCH INTERNATIONAL 2014; 2014:610474. [PMID: 24719876 PMCID: PMC3955675 DOI: 10.1155/2014/610474] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/15/2014] [Indexed: 11/18/2022]
Abstract
Work at high altitude in shifts exposes humans to a new form of chronic intermittent hypoxia, with still unknown health consequences. We have established a rat model resembling this situation, which develops a milder form of right ventricular hypertrophy and pulmonary artery remodelling compared to continuous chronic exposure. We aimed to compare the alterations in pulmonary artery nitric oxide (NO) availability induced by these forms of hypoxia and the mechanisms implicated. Rats were exposed for 46 days to normoxia or hypobaric hypoxia, either continuous (CH) or intermittent (2 day shifts, CIH2x2), and assessed: NO and superoxide anion availability (fluorescent indicators and confocal microscopy); expression of phosphorylated endothelial NO synthase (eNOS), NADPH-oxidase (p22phox), and 3-nitrotyrosine (western blotting); and NADPH-oxidase location (immunohistochemistry). Compared to normoxia, (1) NO availability was reduced and superoxide anion was increased in both hypoxic groups, with a larger effect in CH, (2) eNOS expression was only reduced in CH, (3) NADPH-oxidase was similarly increased in both hypoxic groups, and (4) 3-nitrotyrosine was increased to a larger extent in CH. In conclusion, intermittent hypoxia reduces NO availability through superoxide anion destruction, without reducing its synthesis, while continuous hypoxia affects both, producing larger nitrosative damage which could be related to the more severe cardiovascular alterations.
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Veit F, Pak O, Egemnazarov B, Roth M, Kosanovic D, Seimetz M, Sommer N, Ghofrani HA, Seeger W, Grimminger F, Brandes RP, Schermuly RT, Weissmann N. Function of NADPH oxidase 1 in pulmonary arterial smooth muscle cells after monocrotaline-induced pulmonary vascular remodeling. Antioxid Redox Signal 2013; 19:2213-31. [PMID: 23706097 DOI: 10.1089/ars.2012.4904] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
AIMS Chronic hypoxia induces pulmonary hypertension (PH) that is concomitant with pulmonary vascular remodeling. Reactive oxygen species (ROS) are thought to play a major role in this. Recent findings suggest that ROS production by NADPH oxidase 4 (Nox4) is important in this remodeling. We investigated whether ROS production by Nox is also important in an inflammatory model of monocrotaline (MCT)-induced PH. We examined ROS production, their possible sources, and their impact on the function of pulmonary arterial smooth muscle cells (PASMC) isolated from MCT-treated and healthy rats. RESULTS MCT-PASMC showed increased intracellular superoxide production, migration, and proliferation compared with healthy controls due to increased Nox1 expression. A comparison of PASMC from MCT- and nontreated rats revealed an up-regulation of Sod2, Nrf2, cyclin D1, and matrix metalloproteinase-9 (MMP-9) as well as an increased phosphorylation of cofilin and extracellular signal-regulated kinases (Erk). Expression of Sod2, Nrf2, and cyclin D1 and phosphorylation of cofilin and Erk were Nox1 dependent. INNOVATION The role of ROS in PH is not fully understood. Mitochondria and Nox have been suggested as sources of altered ROS generation in PH, yet it remains unclear whether increased or decreased ROS contributes to the development of PH. Our studies provide evidence that for different triggers of PH, different Nox isoforms regulate proliferation and migration of PASMC. CONCLUSION In contrast to hypoxia-induced PH, Nox1 but not Nox4 is responsible for pathophysiological proliferation and migration of PASMC in an inflammatory model of MCT-induced PH via increased superoxide production. Thus, different Nox isoforms may be targeted in different forms of PH.
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Affiliation(s)
- Florian Veit
- 1 Excellencecluster Cardio-Pulmonary System (ECCPS), German Lung Center (DZL), Universities of Giessen and Marburg Lung Center (UGMLC), Justus-Liebig-University Giessen , Giessen, Germany
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Clanton TL, Hogan MC, Gladden LB. Regulation of cellular gas exchange, oxygen sensing, and metabolic control. Compr Physiol 2013; 3:1135-90. [PMID: 23897683 DOI: 10.1002/cphy.c120030] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cells must continuously monitor and couple their metabolic requirements for ATP utilization with their ability to take up O2 for mitochondrial respiration. When O2 uptake and delivery move out of homeostasis, cells have elaborate and diverse sensing and response systems to compensate. In this review, we explore the biophysics of O2 and gas diffusion in the cell, how intracellular O2 is regulated, how intracellular O2 levels are sensed and how sensing systems impact mitochondrial respiration and shifts in metabolic pathways. Particular attention is paid to how O2 affects the redox state of the cell, as well as the NO, H2S, and CO concentrations. We also explore how these agents can affect various aspects of gas exchange and activate acute signaling pathways that promote survival. Two kinds of challenges to gas exchange are also discussed in detail: when insufficient O2 is available for respiration (hypoxia) and when metabolic requirements test the limits of gas exchange (exercising skeletal muscle). This review also focuses on responses to acute hypoxia in the context of the original "unifying theory of hypoxia tolerance" as expressed by Hochachka and colleagues. It includes discourse on the regulation of mitochondrial electron transport, metabolic suppression, shifts in metabolic pathways, and recruitment of cell survival pathways preventing collapse of membrane potential and nuclear apoptosis. Regarding exercise, the issues discussed relate to the O2 sensitivity of metabolic rate, O2 kinetics in exercise, and influences of available O2 on glycolysis and lactate production.
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Affiliation(s)
- T L Clanton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA.
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Connolly MJ, Prieto-Lloret J, Becker S, Ward JPT, Aaronson PI. Hypoxic pulmonary vasoconstriction in the absence of pretone: essential role for intracellular Ca2+ release. J Physiol 2013; 591:4473-98. [PMID: 23774281 DOI: 10.1113/jphysiol.2013.253682] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) maintains blood oxygenation during acute hypoxia but contributes to pulmonary hypertension during chronic hypoxia. The mechanisms of HPV remain controversial, in part because HPV is usually studied in the presence of agonist-induced preconstriction ('pretone'). This potentiates HPV but may obscure and distort its underlying mechanisms. We therefore carried out an extensive assessment of proposed mechanisms contributing to HPV in isolated intrapulmonary arteries (IPAs) in the absence of pretone by using a conventional small vessel myograph. Hypoxia elicited a biphasic constriction consisting of a small transient (phase 1) superimposed upon a sustained (phase 2) component. Neither phase was affected by the L-type Ca2+ channel antagonists diltiazem (10 and 30 μm) or nifedipine (3 μm). Application of the store-operated Ca2+ entry (SOCE) blockers BTP2 (10 μm) or SKF96365 (50 μm) attenuated phase 2 but not phase 1, whereas a lengthy (30 min) incubation in Ca2+-free physiological saline solution similarly reduced phase 2 but abolished phase 1. No further effect of inhibition of HPV was observed if the sarco/endoplasmic reticulum Ca2+-ATPase inhibitor cyclopiazonic acid (30 μm) was also applied during the 30 min incubation in Ca2+-free physiological saline solution. Pretreatment with 10 μm ryanodine and 15 mm caffeine abolished both phases, whereas treatment with 100 μm ryanodine attenuated both phases. The two-pore channel blocker NED-19 (1 μm) and the nicotinic acid adenine dinucleotide phosphate (NAADP) antagonist BZ194 (200 μm) had no effect on either phase of HPV. The lysosomal Ca2+-depleting agent concanamycin (1 μm) enhanced HPV if applied during hypoxia, but had no effect on HPV during a subsequent hypoxic challenge. The cyclic ADP ribose antagonist 8-bromo-cyclic ADP ribose (30 μm) had no effect on either phase of HPV. Neither the Ca2+-sensing receptor (CaSR) blocker NPS2390 (0.1 and 10 μm) nor FK506 (10 μm), a drug which displaces FKBP12.6 from ryanodine receptor 2 (RyR2), had any effect on HPV. HPV was virtually abolished by the rho kinase blocker Y-27632 (1 μm) and attenuated by the protein kinase C inhibitor Gö6983 (3 μm). Hypoxia for 45 min caused a significant increase in the ratio of oxidised to reduced glutathione (GSSG/GSH). HPV was unaffected by the NADPH oxidase inhibitor VAS2870 (10 μm), whereas phase 2 was inhibited but phase 1 was unaffected by the antioxidants ebselen (100 μm) and TEMPOL (3 mm). We conclude that both phases of HPV in this model are mainly dependent on [Ca2+]i release from the sarcoplasmic reticulum. Neither phase of HPV requires voltage-gated Ca2+ entry, but SOCE contributes to phase 2. We can detect no requirement for cyclic ADP ribose, NAADP-dependent lysosomal Ca2+ release, activation of the CaSR, or displacement of FKBP12.6 from RyR2 for either phase of HPV. Sustained HPV is associated with an oxidising shift in the GSSG/GSH redox potential and is inhibited by the antioxidants ebselen and TEMPOL, consistent with the concept that it requires an oxidising shift in the cell redox state or the generation of reactive oxygen species.
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Affiliation(s)
- Michelle J Connolly
- P. I. Aaronson: Room 1.19, Henriette Raphael House, Guy's Campus, King's College London, London SE1 9HN, UK.
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Kahles T, Brandes RP. Which NADPH oxidase isoform is relevant for ischemic stroke? The case for nox 2. Antioxid Redox Signal 2013; 18:1400-17. [PMID: 22746273 PMCID: PMC3603497 DOI: 10.1089/ars.2012.4721] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
UNLABELLED Significance and Recent Advances: Ischemic stroke is the leading cause of disability and third in mortality in industrialized nations. Immediate restoration of cerebral blood flow is crucial to salvage brain tissue, but only few patients are eligible for recanalization therapy. Thus, the need for alternative neuroprotective strategies is huge, and antioxidant interventions have long been studied in this context. Reactive oxygen species (ROS) physiologically serve as signaling molecules, but excessive amounts of ROS, as generated during ischemia/reperfusion (I/R), contribute to tissue injury. CRITICAL ISSUES Nevertheless and despite a strong rational of ROS being a pharmacological target, all antioxidant interventions failed to improve functional outcome in human clinical trials. Antioxidants may interfere with physiological functions of ROS or do not reach the crucial target structures of ROS-induced injury effectively. FUTURE DIRECTIONS Thus, a potentially more promising approach is the inhibition of the source of disease-promoting ROS. Within recent years, NADPH oxidases (Nox) of the Nox family have been identified as mediators of neuronal pathology. As, however, several Nox homologs are expressed in neuronal tissue, and as many of the pharmacological inhibitors employed are rather unspecific, the concept of Nox as mediators of brain damage is far from being settled. In this review, we will discuss the contribution of Nox homologs to I/R injury at large as well as to neuronal damage in particular. We will illustrate that the current data provide evidence for Nox2 as the most important NADPH oxidase mediating cerebral injury.
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Affiliation(s)
- Timo Kahles
- Institut für Kardiovaskuläre Physiologie, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main, Germany
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Waypa GB, Marks JD, Guzy RD, Mungai PT, Schriewer JM, Dokic D, Ball MK, Schumacker PT. Superoxide generated at mitochondrial complex III triggers acute responses to hypoxia in the pulmonary circulation. Am J Respir Crit Care Med 2013; 187:424-32. [PMID: 23328522 DOI: 10.1164/rccm.201207-1294oc] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
RATIONALE The role of reactive oxygen species (ROS) signaling in the O(2) sensing mechanism underlying acute hypoxic pulmonary vasoconstriction (HPV) has been controversial. Although mitochondria are important sources of ROS, studies using chemical inhibitors have yielded conflicting results, whereas cellular models using genetic suppression have precluded in vivo confirmation. Hence, genetic animal models are required to test mechanistic hypotheses. OBJECTIVES We tested whether mitochondrial Complex III is required for the ROS signaling and vasoconstriction responses to acute hypoxia in pulmonary arteries (PA). METHODS A mouse permitting Cre-mediated conditional deletion of the Rieske iron-sulfur protein (RISP) of Complex III was generated. Adenoviral Cre recombinase was used to delete RISP from isolated PA vessels or smooth muscle cells (PASMC). MEASUREMENTS AND MAIN RESULTS In PASMC, RISP depletion abolished hypoxia-induced increases in ROS signaling in the mitochondrial intermembrane space and cytosol, and it abrogated hypoxia-induced increases in [Ca(2+)](i). In isolated PA vessels, RISP depletion abolished hypoxia-induced ROS signaling in the cytosol. Breeding the RISP mice with transgenic mice expressing tamoxifen-activated Cre in smooth muscle permitted the depletion of RISP in PASMC in vivo. Precision-cut lung slices from those mice revealed that RISP depletion abolished hypoxia-induced increases in [Ca(2+)](i) of the PA. In vivo RISP depletion in smooth muscle attenuated the acute hypoxia-induced increase in right ventricular systolic pressure in anesthetized mice. CONCLUSIONS Acute hypoxia induces superoxide release from Complex III of smooth muscle cells. These oxidant signals diffuse into the cytosol and trigger increases in [Ca(2+)](i) that cause acute hypoxic pulmonary vasoconstriction.
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Affiliation(s)
- Gregory B Waypa
- Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Lung oxidative damage by hypoxia. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:856918. [PMID: 22966417 PMCID: PMC3433143 DOI: 10.1155/2012/856918] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 07/11/2012] [Indexed: 12/12/2022]
Abstract
One of the most important functions of lungs is to maintain an adequate oxygenation in the organism. This organ can be affected by hypoxia facing both physiological and pathological situations. Exposure to this condition favors the increase of reactive oxygen species from mitochondria, as from NADPH oxidase, xanthine oxidase/reductase, and nitric oxide synthase enzymes, as well as establishing an inflammatory process. In lungs, hypoxia also modifies the levels of antioxidant substances causing pulmonary oxidative damage. Imbalance of redox state in lungs induced by hypoxia has been suggested as a participant in the changes observed in lung function in the hypoxic context, such as hypoxic vasoconstriction and pulmonary edema, in addition to vascular remodeling and chronic pulmonary hypertension. In this work, experimental evidence that shows the implied mechanisms in pulmonary redox state by hypoxia is reviewed. Herein, studies of cultures of different lung cells and complete isolated lung and tests conducted in vivo in the different forms of hypoxia, conducted in both animal models and humans, are described.
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Mittal M, Gu XQ, Pak O, Pamenter ME, Haag D, Fuchs DB, Schermuly RT, Ghofrani HA, Brandes RP, Seeger W, Grimminger F, Haddad GG, Weissmann N. Hypoxia induces Kv channel current inhibition by increased NADPH oxidase-derived reactive oxygen species. Free Radic Biol Med 2012; 52:1033-42. [PMID: 22222468 DOI: 10.1016/j.freeradbiomed.2011.12.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 11/23/2011] [Accepted: 12/03/2011] [Indexed: 10/24/2022]
Abstract
There is current discussion whether reactive oxygen species are up- or downregulated in the pulmonary circulation during hypoxia, from which sources (i.e., mitochondria or NADPH oxidases) they are derived, and what the downstream targets of ROS are. We recently showed that the NADPH oxidase homolog NOX4 is upregulated in hypoxia-induced pulmonary hypertension in mice and contributes to the vascular remodeling in pulmonary hypertension. We here tested the hypothesis that NOX4 regulates K(v) channels via an increased ROS formation after prolonged hypoxia. We showed that (1) NOX4 is upregulated in hypoxia-induced pulmonary hypertension in rats and isolated rat pulmonary arterial smooth muscle cells (PASMC) after 3days of hypoxia, and (2) that NOX4 is a major contributor to increased reactive oxygen species (ROS) after hypoxia. Our data indicate colocalization of K(v)1.5 and NOX4 in isolated PASMC. The NADPH oxidase inhibitor and ROS scavenger apocynin as well as NOX4 siRNA reversed the hypoxia-induced decrease in K(v) current density whereas the protein levels of the channels remain unaffected by siNOX4 treatment. Determination of cysteine oxidation revealed increased NOX4-mediated K(v)1.5 channel oxidation. We conclude that sustained hypoxia decreases K(v) channel currents by a direct effect of a NOX4-derived increase in ROS.
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Affiliation(s)
- Manish Mittal
- Excellence Cluster Cardio-Pulmonary System, University of Giessen Lung Center, Justus-Liebig-University, Medical Clinic II/V, Aulweg 130, Giessen 35392, Germany
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Lung cell hypoxia: role of mitochondrial reactive oxygen species signaling in triggering responses. Ann Am Thorac Soc 2012; 8:477-84. [PMID: 22052923 DOI: 10.1513/pats.201103-032mw] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lung cells experience hypoxia during development, during travel to high altitude, and in acute and chronic lung diseases. The functional responses evoked by hypoxia are diverse and generally act to protect the cells from hypoxic injury, although some lung cell responses are counterproductive because they degrade normal function of the organ. The cellular O(2) sensor responsible for many of these responses involves the mitochondrial electron transport chain. Under hypoxic conditions, increased release of reactive oxygen species from the inner mitochondrial membrane to the intermembrane space leads to the activation of transcription factors, including hypoxia-inducible factor, activation of hypoxic pulmonary vasoconstriction, activation of AMP-dependent protein kinase, and internalization of the membrane Na,K-ATPase from the basolateral membrane of alveolar epithelial cells. Although the specific targets of reactive oxygen species signals are not fully understood, this signaling pathway is critical for development and for normal lung responses in the newborn and the mature lung.
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Paddenberg R, Tiefenbach M, Faulhammer P, Goldenberg A, Gries B, Pfeil U, Lips KS, Piruat JI, López-Barneo J, Schermuly RT, Weissmann N, Kummer W. Mitochondrial complex II is essential for hypoxia-induced pulmonary vasoconstriction of intra- but not of pre-acinar arteries. Cardiovasc Res 2012; 93:702-10. [DOI: 10.1093/cvr/cvr359] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Abstract
It has been known for more than 60 years, and suspected for over 100, that alveolar hypoxia causes pulmonary vasoconstriction by means of mechanisms local to the lung. For the last 20 years, it has been clear that the essential sensor, transduction, and effector mechanisms responsible for hypoxic pulmonary vasoconstriction (HPV) reside in the pulmonary arterial smooth muscle cell. The main focus of this review is the cellular and molecular work performed to clarify these intrinsic mechanisms and to determine how they are facilitated and inhibited by the extrinsic influences of other cells. Because the interaction of intrinsic and extrinsic mechanisms is likely to shape expression of HPV in vivo, we relate results obtained in cells to HPV in more intact preparations, such as intact and isolated lungs and isolated pulmonary vessels. Finally, we evaluate evidence regarding the contribution of HPV to the physiological and pathophysiological processes involved in the transition from fetal to neonatal life, pulmonary gas exchange, high-altitude pulmonary edema, and pulmonary hypertension. Although understanding of HPV has advanced significantly, major areas of ignorance and uncertainty await resolution.
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Affiliation(s)
- J. T. Sylvester
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
| | - Larissa A. Shimoda
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
| | - Philip I. Aaronson
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
| | - Jeremy P. T. Ward
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College, London, United Kingdom
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Frazziano G, Moreno L, Moral-Sanz J, Menendez C, Escolano L, Gonzalez C, Villamor E, Alvarez-Sala JL, Cogolludo AL, Perez-Vizcaino F. Neutral sphingomyelinase, NADPH oxidase and reactive oxygen species. Role in acute hypoxic pulmonary vasoconstriction. J Cell Physiol 2011; 226:2633-40. [PMID: 21792922 DOI: 10.1002/jcp.22611] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The molecular mechanisms underlying hypoxic pulmonary vasoconstriction (HPV) are not yet properly understood. Mitochondrial electron transport chain (ETC) and NADPH oxidase have been proposed as possible oxygen sensors, with derived reactive oxygen species (ROS) playing key roles in coupling the sensor(s) to the contractile machinery. We have recently reported that activation of neutral sphingomyelinase (nSMase) and protein kinase C ζ (PKCζ) participate in the signalling cascade of HPV. Herein, we studied the significance of nSMase in controlling ROS production rate in rat pulmonary artery (PA) smooth muscle cells and thereby HPV in rat PA. ROS production (analyzed by dichlorofluorescein and dihydroethidium fluorescence) was increased by hypoxia in endothelium-denuded PA segments and their inhibition prevented hypoxia-induced voltage-gated potassium channel (K(V) ) inhibition and pulmonary vasoconstriction. Consistently, H(2) O(2) , or its analogue t-BHP, decreased K(V) currents and induced a contractile response, mimicking the effects of hypoxia. Inhibitors of mitochondrial ETC (rotenone) and NADPH oxidase (apocynin) prevented hypoxia-induced ROS production, K(V) channel inhibition and vasoconstriction. Hypoxia induced p47(phox) phosphorylation and its interaction with caveolin-1. Inhibition of nSMase (GW4869) or PKCζ prevented p47(phox) phosphorylation and ROS production. The increase in ceramide induced by hypoxia (analyzed by immunocytochemistry) was inhibited by rotenone. Exogenous ceramide increased ROS production in a PKCζ sensitive manner. We propose an integrated signalling pathway for HPV which includes nSMase-PKCζ-NADPH oxidase as a necessary step required for ROS production and vasoconstriction.
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Affiliation(s)
- Giovanna Frazziano
- Department of Pharmacology, School of Medicine, University Complutense of Madrid, Madrid, Spain
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Nisbet RE, Sutliff RL, Hart CM. The role of peroxisome proliferator-activated receptors in pulmonary vascular disease. PPAR Res 2011; 2007:18797. [PMID: 17710111 PMCID: PMC1940049 DOI: 10.1155/2007/18797] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2007] [Accepted: 04/30/2007] [Indexed: 02/07/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone
receptor superfamily that regulate diverse physiological processes ranging from lipogenesis to inflammation. Recent evidence has
established potential roles of PPARs in both systemic and pulmonary vascular disease and function. Existing treatment strategies
for pulmonary hypertension, the most common manifestation of pulmonary vascular disease, are limited by an incomplete
understanding of the underlying disease pathogenesis and lack of efficacy indicating an urgent need for new approaches to treat
this disorder. Derangements in pulmonary endothelial-derived mediators and endothelial dysfunction have been shown to play a
pivotal role in pulmonary hypertension pathogenesis. Therefore, the following review will focus on selected mediators implicated
in pulmonary vascular dysfunction and evidence that PPARs, in particular PPARγ, participate in their regulation and may provide
a potential novel therapeutic target for the treatment of pulmonary hypertension.
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Affiliation(s)
- Rachel E. Nisbet
- Department of Medicine, Emory University, Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
- *Rachel E. Nisbet:
| | - Roy L. Sutliff
- Department of Medicine, Emory University, Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
| | - C. Michael Hart
- Department of Medicine, Emory University, Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA
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Korde AS, Yadav VR, Zheng YM, Wang YX. Primary role of mitochondrial Rieske iron-sulfur protein in hypoxic ROS production in pulmonary artery myocytes. Free Radic Biol Med 2011; 50:945-52. [PMID: 21238580 PMCID: PMC3051030 DOI: 10.1016/j.freeradbiomed.2011.01.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 01/04/2011] [Accepted: 01/06/2011] [Indexed: 12/20/2022]
Abstract
This study was designed to determine whether: (1) hypoxia could directly affect ROS production in isolated mitochondria and mitochondrial complex III from pulmonary artery smooth muscle cells (PASMCs) and (2) Rieske iron-sulfur protein in complex III might mediate hypoxic ROS production, leading to hypoxic pulmonary vasoconstriction (HPV). Our data, for the first time, demonstrate that hypoxia significantly enhances ROS production, measured by the standard ROS indicator dichlorodihydrofluorescein/diacetate, in isolated mitochondria from PASMCs. Studies using the newly developed, specific ROS biosensor pHyPer have found that hypoxia increases mitochondrial ROS generation in isolated PASMCs as well. Hypoxic ROS production has also been observed in isolated complex III. Rieske iron-sulfur protein silencing using siRNA abolishes the hypoxic ROS formation in isolated PASM complex III, mitochondria, and cells, whereas Rieske iron-sulfur protein overexpression produces the opposite effect. Rieske iron-sulfur protein silencing inhibits the hypoxic increase in [Ca(2+)](i) in PASMCs and hypoxic vasoconstriction in isolated PAs. These findings together provide novel evidence that mitochondria are the direct hypoxic targets in PASMCs, in which Rieske iron-sulfur protein in complex III may serve as an essential, primary molecule that mediates the hypoxic ROS generation, leading to an increase in intracellular Ca(2+) in PASMCs and HPV.
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Affiliation(s)
| | | | | | - Yong-Xiao Wang
- Corresponding author: Dr. Yong-Xiao Wang Albany Medical College Center for Cardiovascular Sciences (MC-8) 47 New Scotland Avenue Albany, NY 12208 Phone: (518)-262-9506 Fax: (518)-262-8101
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Fuchs B, Rupp M, Ghofrani HA, Schermuly RT, Seeger W, Grimminger F, Gudermann T, Dietrich A, Weissmann N. Diacylglycerol regulates acute hypoxic pulmonary vasoconstriction via TRPC6. Respir Res 2011; 12:20. [PMID: 21294865 PMCID: PMC3042943 DOI: 10.1186/1465-9921-12-20] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 02/04/2011] [Indexed: 11/25/2022] Open
Abstract
Background Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism of the lung that matches blood perfusion to alveolar ventilation to optimize gas exchange. Recently we have demonstrated that acute but not sustained HPV is critically dependent on the classical transient receptor potential 6 (TRPC6) channel. However, the mechanism of TRPC6 activation during acute HPV remains elusive. We hypothesize that a diacylglycerol (DAG)-dependent activation of TRPC6 regulates acute HPV. Methods We investigated the effect of the DAG analog 1-oleoyl-2-acetyl-sn-glycerol (OAG) on normoxic vascular tone in isolated perfused and ventilated mouse lungs from TRPC6-deficient and wild-type mice. Moreover, the effects of OAG, the DAG kinase inhibitor R59949 and the phospholipase C inhibitor U73122 on the strength of HPV were investigated compared to those on non-hypoxia-induced vasoconstriction elicited by the thromboxane mimeticum U46619. Results OAG increased normoxic vascular tone in lungs from wild-type mice, but not in lungs from TRPC6-deficient mice. Under conditions of repetitive hypoxic ventilation, OAG as well as R59949 dose-dependently attenuated the strength of acute HPV whereas U46619-induced vasoconstrictions were not reduced. Like OAG, R59949 mimicked HPV, since it induced a dose-dependent vasoconstriction during normoxic ventilation. In contrast, U73122, a blocker of DAG synthesis, inhibited acute HPV whereas U73343, the inactive form of U73122, had no effect on HPV. Conclusion These findings support the conclusion that the TRPC6-dependency of acute HPV is induced via DAG.
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Affiliation(s)
- Beate Fuchs
- Excellence Cluster Cardio-Pulmonary System, University of Giessen Lung Center, Department of Internal Medicine II, Justus-Liebig-University Giessen, Giessen, Germany
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Gonzalez C, Agapito MT, Rocher A, Gomez-Niño A, Rigual R, Castañeda J, Conde SV, Obeso A. A revisit to O2 sensing and transduction in the carotid body chemoreceptors in the context of reactive oxygen species biology. Respir Physiol Neurobiol 2010; 174:317-30. [PMID: 20833275 DOI: 10.1016/j.resp.2010.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2010] [Revised: 08/31/2010] [Accepted: 09/01/2010] [Indexed: 11/25/2022]
Abstract
Oxygen-sensing and transduction in purposeful responses in cells and organisms is of great physiological and medical interest. All animals, including humans, encounter in their lifespan many situations in which oxygen availability might be insufficient, whether acutely or chronically, physiologically or pathologically. Therefore to trace at the molecular level the sequence of events or steps connecting the oxygen deficit with the cell responses is of interest in itself as an achievement of science. In addition, it is also of great medical interest as such knowledge might facilitate the therapeutical approach to patients and to design strategies to minimize hypoxic damage. In our article we define the concepts of sensors and transducers, the steps of the hypoxic transduction cascade in the carotid body chemoreceptor cells and also discuss current models of oxygen- sensing (bioenergetic, biosynthetic and conformational) with their supportive and unsupportive data from updated literature. We envision oxygen-sensing in carotid body chemoreceptor cells as a process initiated at the level of plasma membrane and performed by a hemoprotein, which might be NOX4 or a hemoprotein not yet chemically identified. Upon oxygen-desaturation, the sensor would experience conformational changes allosterically transmitted to oxygen regulated K+ channels, the initial effectors in the transduction cascade. A decrease in their opening probability would produce cell depolarization, activation of voltage dependent calcium channels and release of neurotransmitters. Neurotransmitters would activate the nerve endings of the carotid body sensory nerve to convey the information of the hypoxic situation to the central nervous system that would command ventilation to fight hypoxia.
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Affiliation(s)
- C Gonzalez
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular y CIBER de Enfermedades Respiratorias, Universidad de Valladolid, Consejo Superior de Investigaciones Científicas e Instituto Carlos III, Facultad de Medicina, 47005 Valladolid, Spain.
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Gillespie MN, Pastukh VM, Ruchko MV. Controlled DNA "damage" and repair in hypoxic signaling. Respir Physiol Neurobiol 2010; 174:244-51. [PMID: 20831905 DOI: 10.1016/j.resp.2010.08.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 08/31/2010] [Indexed: 12/29/2022]
Abstract
Hypoxia, a fundamental stimulus in biology and medicine, uses reactive oxygen species (ROS) as second messengers. A surprising target of hypoxia-generated ROS is specific bases within hypoxic response elements (HREs) of the VEGF and other hypoxia-inducible genes. Oxidative modifications coincide with the onset of mRNA accumulation and are localized to transcriptionally active mono-nucleosomes. The oxidative base modifications are removed by the base excision DNA repair pathway for which one of its components, the bifunctional transcriptional co-activator and DNA endonuclease Ref-1/Ape1, is critical for transcription complex assembly. Mimicking the effect of hypoxia by introducing an abasic site in an oligonucleotide model of the VEGF HRE, altered transcription factor binding, enhanced sequence flexibility, and engendered more robust reporter gene expression. These observations suggest that controlled DNA "damage" and repair, mediated by ROS used as second messengers and critically involving the base excision pathway of DNA repair, respectively, are important for hypoxia-induced transcriptional activation.
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Affiliation(s)
- Mark N Gillespie
- Department of Pharmacology and Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688-0002, United States.
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41
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Connolly MJ, Aaronson PI. Cell redox state and hypoxic pulmonary vasoconstriction: recent evidence and possible mechanisms. Respir Physiol Neurobiol 2010; 174:165-74. [PMID: 20801239 DOI: 10.1016/j.resp.2010.08.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 10/24/2022]
Abstract
During alveolar hypoxia, hypoxic pulmonary vasoconstriction (HPV) maintains blood oxygenation near optimum via incompletely defined mechanisms. It is proposed that a hypoxia-induced rise in the intracellular concentration of reactive oxygen species (ROS) or an oxidising shift in the cytoplasmic redox state provides the signal which initiates the constriction of pulmonary arteries (PA), although this is controversial. Here, we review recent investigations demonstrating that hypoxia causes a rise in [ROS] in PA smooth muscle, and that ROS and antioxidants have effects on PA which would be predicted if cell oxidation causes contraction. We argue that intracellular Ca2+ release and Ca2+-sensitisation are the key effector mechanisms causing HPV, and discuss evidence that both processes are promoted by ROS or oxidative protein modifications. We conclude that while it is plausible that an increase in cytoplasmic [ROS] activates HPV effector mechanisms, proving this link will require the determination of whether hypoxia causes oxidative modifications of proteins involved in Ca2+ homeostasis and sensitisation.
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Affiliation(s)
- Michelle J Connolly
- Division of Asthma, Allergy and Lung Biology, King's College London, United Kingdom
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The role of redox changes in oxygen sensing. Respir Physiol Neurobiol 2010; 174:182-91. [PMID: 20801237 DOI: 10.1016/j.resp.2010.08.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 08/17/2010] [Accepted: 08/20/2010] [Indexed: 11/20/2022]
Abstract
The specialized oxygen-sensing tissues include the carotid body and arterial smooth muscle cells in the pulmonary artery (PA) and ductus arteriosus (DA). We discuss the evidence that changes in oxygen tension are sensed through changes in redox status. "Redox" changes imply the giving or accepting of electrons. This might occur through the direct tunneling of electrons from mitochondria or redox couples to an effector protein (e.g. ion channel). Alternatively, the electron might be transferred through reactive oxygen species from mitochondria or an NADPH oxidase isoform. The PA's response to hypoxia and DA's response to normoxia result from reduction or oxidation, respectively. These opposing redox stimuli lead to K+ channel inhibition, membrane depolarization and an increase in cytosolic calcium and/or calcium sensitization that causes contraction. In the neuroendocrine cells (the type 1 cell of the carotid body, neuroepithelial body and adrenomedullary cells), the response is secretion. We examine the roles played by superoxide anion, hydrogen peroxide and the anti-oxidant enzymes in the signaling of oxygen tensions.
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Fuchs B, Sommer N, Dietrich A, Schermuly RT, Ghofrani HA, Grimminger F, Seeger W, Gudermann T, Weissmann N. Redox signaling and reactive oxygen species in hypoxic pulmonary vasoconstriction. Respir Physiol Neurobiol 2010; 174:282-91. [PMID: 20801235 DOI: 10.1016/j.resp.2010.08.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/20/2010] [Accepted: 08/20/2010] [Indexed: 11/16/2022]
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is an essential physiological mechanism of the lung that matches blood perfusion with alveolar ventilation to optimize gas exchange. Perturbations of HPV, as may occur in pneumonia or adult respiratory distress syndrome, can cause life-threatening hypoxemia. Despite intensive research for decades, the molecular mechanisms of HPV have not been fully elucidated. Reactive oxygen species (ROS) and changes in the cellular redox state are proposed to link O2 sensing and pulmonary arterial smooth muscle cell contraction underlying HPV. In this regard, mitochondria and NAD(P)H oxidases are discussed as sources of ROS. However, there is controversy whether ROS levels decrease or increase during hypoxia. With this background we summarize the current knowledge on the role of ROS and redox state in HPV.
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Affiliation(s)
- Beate Fuchs
- Excellence Cluster Cardio-Pulmonary System, University of Giessen Lung Center, Department of Internal Medicine II, Justus-Liebig-University Giessen, Aulweg 130, 35392 Giessen, Germany
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Interactions between calcium and reactive oxygen species in pulmonary arterial smooth muscle responses to hypoxia. Respir Physiol Neurobiol 2010; 174:221-9. [PMID: 20801238 DOI: 10.1016/j.resp.2010.08.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 02/07/2023]
Abstract
In contrast to the systemic vasculature, where hypoxia causes vasodilation, pulmonary arteries constrict in response to hypoxia. The mechanisms underlying this unique response have been the subject of investigation for over 50 years, and still remain a topic of great debate. Over the last 20 years, there has emerged a general consensus that both increases in intracellular calcium concentration and changes in reactive oxygen species (ROS) generation play key roles in the pulmonary vascular response to hypoxia. Controversy exists, however, regarding whether ROS increase or decrease during hypoxia, the source of ROS, and the mechanisms by which changes in ROS might impact intracellular calcium, and vice versa. This review will discuss the mechanisms regulating [Ca2+]i and ROS in PASMCs, and the interaction between ROS and Ca2+ signaling during exposure to acute hypoxia.
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Wang YX, Zheng YM. Role of ROS signaling in differential hypoxic Ca2+ and contractile responses in pulmonary and systemic vascular smooth muscle cells. Respir Physiol Neurobiol 2010; 174:192-200. [PMID: 20713188 DOI: 10.1016/j.resp.2010.08.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 08/06/2010] [Accepted: 08/09/2010] [Indexed: 01/25/2023]
Abstract
Hypoxia causes a large increase in [Ca2+]i and attendant contraction in pulmonary artery smooth muscle cells (PASMCs), but not in systemic artery SMCs. The different responses meet the respective functional needs in these two distinct vascular myocytes; however, the underlying molecular mechanisms are not well known. We and other investigators have provided extensive evidence to reveal that voltage-dependent K+ (KV) channels, canonical transient receptor potential (TRPC) channels, ryanodine receptor Ca2+ release channels (RyRs), cyclic adenosine diphosphate-ribose, FK506 binding protein 12.6, protein kinase C, NADPH oxidase and reactive oxygen species (ROS) are the essential effectors and signaling intermediates in the hypoxic increase in [Ca2+]i in PASMCs and HPV, but they may not primarily underlie the diverse cellular responses in pulmonary and systemic vascular myocytes. Hypoxia significantly increases mitochondrial ROS generation in PASMCs, which can induce intracellular Ca2+ release by opening RyRs, and may also cause extracellular Ca2+ influx by inhibiting KV channels and activating TRPC channels, leading to a large increase in [Ca2+]i in PASMCs and HPV. In contrast, hypoxia has no or a minor effect on mitochondrial ROS generation in systemic SMCs, thereby causing no change or a negligible increase in [Ca2+]i and contraction. Further preliminary work indicates that Rieske iron-sulfur protein in the mitochondrial complex III may perhaps serve as a key initial molecular determinant for the hypoxic increase in [Ca2+]i in PASMCs and HPV, suggesting its potential important role in different cellular changes to respond to hypoxic stimulation in pulmonary and systemic artery myocytes. All these findings have greatly improved our understanding of the molecular processes for the differential hypoxic Ca2+ and contractile responses in vascular SMCs from distinct pulmonary and systemic circulation systems.
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Affiliation(s)
- Yong-Xiao Wang
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, USA.
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Waypa GB, Schumacker PT. Hypoxia-induced changes in pulmonary and systemic vascular resistance: where is the O2 sensor? Respir Physiol Neurobiol 2010; 174:201-11. [PMID: 20713189 DOI: 10.1016/j.resp.2010.08.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 08/05/2010] [Accepted: 08/06/2010] [Indexed: 01/06/2023]
Abstract
Pulmonary arteries (PA) constrict in response to alveolar hypoxia, whereas systemic arteries (SA) undergo dilation. These physiological responses reflect the need to improve gas exchange in the lung, and to enhance the delivery of blood to hypoxic systemic tissues. An important unresolved question relates to the underlying mechanism by which the vascular cells detect a decrease in oxygen tension and translate that into a signal that triggers the functional response. A growing body of work implicates the mitochondria, which appear to function as O2 sensors by initiating a redox-signaling pathway that leads to the activation of downstream effectors that regulate vascular tone. However, the direction of this redox signal has been the subject of controversy. Part of the problem has been the lack of appropriate tools to assess redox signaling in live cells. Recent advancements in the development of redox sensors have led to studies that help to clarify the nature of the hypoxia-induced redox signaling by reactive oxygen species (ROS). Moreover, these studies provide valuable insight regarding the basis for discrepancies in earlier studies of the hypoxia-induced mechanism of redox signaling. Based on recent work, it appears that the O2 sensing mechanism in both the PA and SA are identical, that mitochondria function as the site of O2 sensing, and that increased ROS release from these organelles leads to the activation of cell-specific, downstream vascular responses.
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Affiliation(s)
- Gregory B Waypa
- Department of Pediatrics, Division of Neonatology, Northwestern University, Morton Building 4-685, 310 East Superior St, Chicago, IL 60611, USA.
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Chandel NS. Mitochondrial complex III: an essential component of universal oxygen sensing machinery? Respir Physiol Neurobiol 2010; 174:175-81. [PMID: 20708106 DOI: 10.1016/j.resp.2010.08.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 08/03/2010] [Accepted: 08/04/2010] [Indexed: 02/07/2023]
Abstract
Oxygen is necessary for the survival of mammalian cells. In order to maintain adequate cellular oxygenation, mammals have evolved multiple acute and long-term adaptive responses to hypoxia. These include hypoxic increases in erythropoiesis, pulmonary vasoconstriction and carotid body neurosecretion. Collectively, these responses help maintain oxygen homeostasis as oxygen levels remain scarce. There are multiple effectors proposed to underlie these diverse responses to hypoxia including PHD2, AMPK, NADPH oxidases, and mitochondrial complex III. Here I propose a model wherein complex III is integral to oxygen sensing in regulating diverse response to hypoxia.
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Affiliation(s)
- Navdeep S Chandel
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University Medical School, Chicago, IL 60611, USA.
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Lu X, Murphy TC, Nanes MS, Hart CM. PPAR{gamma} regulates hypoxia-induced Nox4 expression in human pulmonary artery smooth muscle cells through NF-{kappa}B. Am J Physiol Lung Cell Mol Physiol 2010; 299:L559-66. [PMID: 20622120 DOI: 10.1152/ajplung.00090.2010] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
NADPH oxidases are a major source of superoxide production in the vasculature. The constitutively active Nox4 subunit, which is selectively upregulated in the lungs of human subjects and experimental animals with pulmonary hypertension, is highly expressed in vascular wall cells. We demonstrated that rosiglitazone, a synthetic agonist of the peroxisome proliferator-activated receptor-γ (PPARγ), attenuated hypoxia-induced pulmonary hypertension, vascular remodeling, Nox4 induction, and reactive oxygen species generation in the mouse lung. The current study examined the molecular mechanisms involved in PPARγ-regulated, hypoxia-induced Nox4 expression in human pulmonary artery smooth muscle cells (HPASMC). Exposing HPASMC to 1% oxygen for 72 h increased Nox4 gene expression and H(2)O(2) production, both of which were reduced by treatment with rosiglitazone during the last 24 h of hypoxia exposure or by treatment with small interfering RNA (siRNA) to Nox4. Hypoxia also increased HPASMC proliferation as well as the activity of a Nox4 promoter luciferase reporter, and these increases were attenuated by rosiglitazone. Chromatin immunoprecipitation assays demonstrated that hypoxia increased binding of the NF-κB subunit, p65, to the Nox4 promoter and that binding was attenuated by rosiglitazone treatment. The role of NF-κB in Nox4 regulation was further supported by demonstrating that overexpression of p65 stimulated Nox4 promoter activity, whereas siRNA to p50 or p65 attenuated hypoxic stimulation of Nox4 promoter activity. These results provide novel evidence for NF-κB-mediated stimulation of Nox4 expression in HPASMC that can be negatively regulated by PPARγ. These data provide new insights into potential mechanisms by which PPARγ activation inhibits Nox4 upregulation and the proliferation of cells in the pulmonary vascular wall to ameliorate pulmonary hypertension and vascular remodeling in response to hypoxia.
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Affiliation(s)
- Xianghuai Lu
- Department of Medicine, Atlanta Veterans Affairs, Emory University Medical Centers, Georgia, USA
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Tual-Chalot S, Guibert C, Muller B, Savineau JP, Andriantsitohaina R, Martinez MC. Circulating microparticles from pulmonary hypertensive rats induce endothelial dysfunction. Am J Respir Crit Care Med 2010; 182:261-8. [PMID: 20339146 DOI: 10.1164/rccm.200909-1347oc] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
RATIONALE Pulmonary arterial hypertension (PAH) is a severe disease characterized by an increase of pulmonary vascular resistance, which is accompanied by functional and structural changes in pulmonary arteries. Microparticles (MPs) have been described as biological vector of endothelial dysfunction in other pathologies. OBJECTIVES The purpose of this work was to characterize circulating MPs during hypoxic PAH and to study their effects on endothelial function. METHODS Male Wistar rats were exposed or not to chronic hypoxia, and normoxic or hypoxic MPs from blood were characterized by flow cytometry. Endothelial cells (ECs) from rat aorta or pulmonary arteries were incubated with MPs, and then expression and phosphorylation of enzymes involved in nitric oxide (NO) and reactive oxygen species productions were analyzed. Hypoxic MPs were injected into rats, and endothelium-dependent relaxation was assessed. MEASUREMENTS AND MAIN RESULTS Circulating levels of MPs from hypoxic rats were twofold higher than those present in normoxic rats. In vitro treatment of ECs with hypoxic MPs reduced NO production in aortas and pulmonary arteries by enhancing phosphorylation of endothelial NO synthase at the inhibitory site. Hypoxic MPs increased oxidative stress only in pulmonary ECs via xanthine oxidase and mitochondrial implication. In vivo injection of hypoxic MPs into rat impaired endothelium-dependent relaxation both in aorta and pulmonary arteries. CONCLUSIONS These data provide evidence that hypoxic circulating MPs induce endothelial dysfunction in rat aorta and pulmonary arteries by decreasing NO production. Moreover, MPs display tissue specificity with respect to increased oxidative stress, which occurs only in pulmonary ECs.
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Affiliation(s)
- Simon Tual-Chalot
- CNRS UMR 6214, Faculté de Médecine, Rue Haute de Reculée, Angers, F-49045 France
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Wang YX, Zheng YM. ROS-dependent signaling mechanisms for hypoxic Ca(2+) responses in pulmonary artery myocytes. Antioxid Redox Signal 2010; 12:611-23. [PMID: 19764882 PMCID: PMC2861542 DOI: 10.1089/ars.2009.2877] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hypoxic exposure causes pulmonary vasoconstriction, which serves as a critical physiologic process that ensures regional alveolar ventilation and pulmonary perfusion in the lungs, but may become an essential pathologic factor leading to pulmonary hypertension. Although the molecular mechanisms underlying hypoxic pulmonary vasoconstriction and associated pulmonary hypertension are uncertain, increasing evidence indicates that hypoxia can result in a significant increase in intracellular reactive oxygen species concentration ([ROS](i)) through the mitochondrial electron-transport chain in pulmonary artery smooth muscle cells (PASMCs). The increased mitochondrial ROS subsequently activate protein kinase C-epsilon (PKCepsilon) and NADPH oxidase (Nox), providing positive mechanisms that further increase [ROS](i). ROS may directly cause extracellular Ca(2+) influx by inhibiting voltage-dependent K(+) (K(V)) channels and opening of store-operated Ca(2+) (SOC) channels, as well as intracellular Ca(2+) release by activating ryanodine receptors (RyRs), leading to an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) and associated contraction. In concert with ROS, PKCepsilon may also affect K(V) channels, SOC channels, and RyRs, contributing to hypoxic Ca(2+) and contractile responses in PASMCs.
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Affiliation(s)
- Yong-Xiao Wang
- Center for Cardiovascular Sciences, Albany Medical College, New York 12208, USA.
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