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West J, Austin E, Fessel JP, Loyd J, Hamid R. Rescuing the BMPR2 signaling axis in pulmonary arterial hypertension. Drug Discov Today 2014; 19:1241-5. [PMID: 24794464 DOI: 10.1016/j.drudis.2014.04.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/24/2014] [Indexed: 01/10/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a lethal disorder characterized by pulmonary arterial remodeling, increased right ventricular systolic pressure (RVSP), vasoconstriction and inflammation. The heritable form of PAH (HPAH) is usually (>80%) caused by mutations in the bone morphogenic protein receptor 2 (BMPR2) gene. Existing treatments for PAH typically focus on the end-stage sequelae of the disease, but do not address underlying mechanisms of vascular obstruction and blood flow and thus, in the long run, have limited effect because they treat the symptoms rather than the cause. Over the past decade, improved understanding of the molecular mechanisms behind the disease has enabled us to consider several novel therapeutic pathways. These include approaches directed toward BMPR2 gene expression, alternative splicing, downstream BMP signaling, metabolic pathways and the role of estrogens and estrogenic compounds in BMP signaling. It is likely that, ultimately, only one or two of these pathways will generate meaningful treatment options, however the potential benefits to PAH patients are still likely to be significant.
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Affiliation(s)
- James West
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Eric Austin
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Joshua P Fessel
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - James Loyd
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rizwan Hamid
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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102
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Tuder RM, Robinson JC, Graham BB. Fat and cardiotoxicity in hereditary pulmonary hypertension. Am J Respir Crit Care Med 2014; 189:247-9. [PMID: 24484329 DOI: 10.1164/rccm.201312-2240ed] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Rubin M Tuder
- 1 Division of Pulmonary Sciences and Critical Care Medicine University of Colorado School of Medicine Aurora, Colorado
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103
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Tuder RM, Archer SL, Dorfmüller P, Erzurum SC, Guignabert C, Michelakis E, Rabinovitch M, Schermuly R, Stenmark KR, Morrell NW. Relevant issues in the pathology and pathobiology of pulmonary hypertension. J Am Coll Cardiol 2014; 62:D4-12. [PMID: 24355640 DOI: 10.1016/j.jacc.2013.10.025] [Citation(s) in RCA: 423] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 10/22/2013] [Indexed: 11/18/2022]
Abstract
Knowledge of the pathobiology of pulmonary hypertension (PH) continues to accelerate. However, fundamental gaps remain in our understanding of the underlying pathological changes in pulmonary arteries and veins in the different forms of this syndrome. Although PH primarily affects the arteries, venous disease is increasingly recognized as an important entity. Moreover, prognosis in PH is determined largely by the status of the right ventricle, rather than the levels of pulmonary artery pressures. It is increasingly clear that although vasospasm plays a role, PH is an obstructive lung panvasculopathy. Disordered metabolism and mitochondrial structure, inflammation, and dysregulation of growth factors lead to a proliferative, apoptosis-resistant state. These abnormalities may be acquired, genetically mediated as a result of mutations in bone morphogenetic protein receptor-2 or activin-like kinase-1, or epigenetically inherited (as a result of epigenetic silencing of genes such as superoxide dismutase-2). There is a pressing need to better understand how the pathobiology leads to severe disease in some patients versus mild PH in others. Recent recognition of a potential role of acquired abnormalities of mitochondrial metabolism in the right ventricular myocytes and pulmonary vascular cells suggests new therapeutic approaches, diagnostic modalities, and biomarkers. Finally, dissection of the role of pulmonary inflammation in the initiation and promotion of PH has revealed a complex yet fascinating interplay with pulmonary vascular remodeling, promising to lead to novel therapeutics and diagnostics. Emerging concepts are also relevant to the pathobiology of PH, including a role for bone marrow and circulating progenitor cells and microribonucleic acids. Continued interest in the interface of the genetic basis of PH and cellular and molecular pathogenetic links should further expand our understanding of the disease.
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Affiliation(s)
- Rubin M Tuder
- Program in Translational Lung Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado.
| | - Stephen L Archer
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Peter Dorfmüller
- Department of Pathology, Marie Lannelongue Hospital, University Paris-Sud, Le Plessis-Robinson, France
| | - Serpil C Erzurum
- Lerner Research Institute and Respiratory Institute, Cleveland Clinic, Cleveland, Ohio
| | - Christophe Guignabert
- INSERM UMR 999, LabEx LERMIT, Marie Lannelongue Hospital and University Paris-Sud, School of Medicine, Kremlin-Bicêtre, France
| | | | - Marlene Rabinovitch
- Cardiovascular Institute and Department of Pediatrics and The Vera Moulton Wall Center for Pulmonary Vascular Disease, Stanford University School of Medicine, Stanford, California
| | - Ralph Schermuly
- Excellence Cluster Cardio-Pulmonary System, German Lung Center, Universities of Giessen and Marburg Lung Center, Justus-Liebig-University, Giessen, Germany
| | - Kurt R Stenmark
- Cardiovascular Pulmonary Laboratory, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
| | - Nicholas W Morrell
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom.
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104
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Vonk-Noordegraaf A, Haddad F, Chin KM, Forfia PR, Kawut SM, Lumens J, Naeije R, Newman J, Oudiz RJ, Provencher S, Torbicki A, Voelkel NF, Hassoun PM. Right heart adaptation to pulmonary arterial hypertension: physiology and pathobiology. J Am Coll Cardiol 2014; 62:D22-33. [PMID: 24355638 DOI: 10.1016/j.jacc.2013.10.027] [Citation(s) in RCA: 721] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 10/22/2013] [Indexed: 12/22/2022]
Abstract
Survival in patients with pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Although pulmonary load is an important determinant of RV systolic function in PAH, there remains a significant variability in RV adaptation to pulmonary hypertension. In this report, the authors discuss the emerging concepts of right heart pathobiology in PAH. More specifically, the discussion focuses on the following questions. 1) How is right heart failure syndrome best defined? 2) What are the underlying molecular mechanisms of the failing right ventricle in PAH? 3) How are RV contractility and function and their prognostic implications best assessed? 4) What is the role of targeted RV therapy? Throughout the report, the authors highlight differences between right and left heart failure and outline key areas of future investigation.
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Affiliation(s)
| | - François Haddad
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, California
| | - Kelly M Chin
- Department of Internal Medicine, Pulmonary Division, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Paul R Forfia
- Pulmonary Hypertension and Right Heart Failure Program, Temple University Hospital, Philadelphia, Pennsylvania
| | - Steven M Kawut
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joost Lumens
- CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Robert Naeije
- Department of Pathophysiology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - John Newman
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Ronald J Oudiz
- The David Geffen School of Medicine at UCLA, Liu Center for Pulmonary Hypertension, Division of Cardiology, Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
| | - Steve Provencher
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Chemin Sainte-Foy, Québec, Canada
| | - Adam Torbicki
- Department of Pulmonary Circulation and Thromboembolic Diseases, Centre of Postgraduate Medical Education, ECZ, Otwock, Poland
| | - Norbert F Voelkel
- Division of Pulmonary and Critical Care Medicine and Victoria Johnson Lab for Lung Research, Virginia Commonwealth University, Richmond, Virginia; Johns Hopkins University, Baltimore, Maryland
| | - Paul M Hassoun
- Department of Internal Medicine, Pulmonary Division, University of Texas Southwestern Medical Center, Dallas, Texas
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105
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Zhao Y, Peng J, Lu C, Hsin M, Mura M, Wu L, Chu L, Zamel R, Machuca T, Waddell T, Liu M, Keshavjee S, Granton J, de Perrot M. Metabolomic heterogeneity of pulmonary arterial hypertension. PLoS One 2014; 9:e88727. [PMID: 24533144 PMCID: PMC3923046 DOI: 10.1371/journal.pone.0088727] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/09/2014] [Indexed: 01/09/2023] Open
Abstract
Although multiple gene and protein expression have been extensively profiled in human pulmonary arterial hypertension (PAH), the mechanism for the development and progression of pulmonary hypertension remains elusive. Analysis of the global metabolomic heterogeneity within the pulmonary vascular system leads to a better understanding of disease progression. Using a combination of high-throughput liquid-and-gas-chromatography-based mass spectrometry, we showed unbiased metabolomic profiles of disrupted glycolysis, increased TCA cycle, and fatty acid metabolites with altered oxidation pathways in the human PAH lung. The results suggest that PAH has specific metabolic pathways contributing to increased ATP synthesis for the vascular remodeling process in severe pulmonary hypertension. These identified metabolites may serve as potential biomarkers for the diagnosis of PAH. By profiling metabolomic alterations of the PAH lung, we reveal new pathogenic mechanisms of PAH, opening an avenue of exploration for therapeutics that target metabolic pathway alterations in the progression of PAH.
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Affiliation(s)
- Yidan Zhao
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (MDP); (YZ)
| | - Jenny Peng
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Catherine Lu
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Michael Hsin
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Marco Mura
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Licun Wu
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Lei Chu
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Ricardo Zamel
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Tiago Machuca
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Thomas Waddell
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Mingyao Liu
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Shaf Keshavjee
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - John Granton
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Marc de Perrot
- Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (MDP); (YZ)
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106
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Bujak R, García-Álvarez A, Rupérez FJ, Nuño-Ayala M, García A, Ruiz-Cabello J, Fuster V, Ibáñez B, Barbas C. Metabolomics reveals metabolite changes in acute pulmonary embolism. J Proteome Res 2014; 13:805-16. [PMID: 24367941 DOI: 10.1021/pr400872j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pulmonary embolism (PE) is a common cardiovascular emergency which can lead to pulmonary hypertension (PH) and right ventricular failure as a consequence of pulmonary arterial bed occlusion. The diagnosis of PE is challenging due to nonspecific clinical presentation, which results in relatively high mortality. Moreover, the pathological factors associated with PE are poorly understood. Metabolomics can provide new highlights which can help in the understanding of the processes and even propose biomarkers for its diagnosis. In order to obtain more information about PE and PH, acute PE was induced in large white pigs and plasma was obtained before and after induction of PE. Metabolic fingerprints from plasma were obtained with LC-QTOF-MS (positive and negative ionization) and GC-Q-MS. Data pretreatment and statistical analysis (uni- and multivariate) were performed in order to compare metabolic fingerprints and to select the metabolites that showed higher loading for the classification (28 from LC and 19 from GC). The metabolites found differentially distributed among groups are mainly related to energy imbalance in hypoxic conditions, such as glycolysis-derived metabolites, ketone bodies, and TCA cycle intermediates, as well as a group of lipidic mediators that could be involved in the transduction of the signals to the cells such as sphingolipids and lysophospholipids, among others. Results presented in this report reveal that combination of LC-MS- and GC-MS-based metabolomics could be a powerful tool for diagnosis and understanding pathophysiological processes due to acute PE.
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Affiliation(s)
- Renata Bujak
- Centre for Metabolomics and Bioanalysis (CEMBIO), Facultad de Farmacia, Universidad CEU San Pablo , Campus Monteprincipe, Boadilla del Monte 28668, Madrid, Spain
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107
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Fessel JP, Flynn CR, Robinson LJ, Penner NL, Gladson S, Kang CJ, Wasserman DH, Hemnes AR, West JD. Hyperoxia synergizes with mutant bone morphogenic protein receptor 2 to cause metabolic stress, oxidant injury, and pulmonary hypertension. Am J Respir Cell Mol Biol 2013; 49:778-87. [PMID: 23742019 DOI: 10.1165/rcmb.2012-0463oc] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) has been associated with a number of different but interrelated pathogenic mechanisms. Metabolic and oxidative stresses have been shown to play important pathogenic roles in a variety of model systems. However, many of these relationships remain at the level of association. We sought to establish a direct role for metabolic stress and oxidant injury in the pathogenesis of PAH. Mice that universally express a disease-causing mutation in bone morphogenic protein receptor 2 (Bmpr2) were exposed to room air or to brief daily hyperoxia (95% oxygen for 3 h) for 6 weeks, and were compared with wild-type animals undergoing identical exposures. In both murine tissues and cultured endothelial cells, the expression of mutant Bmpr2 was sufficient to cause oxidant injury that was particularly pronounced in mitochondrial membranes. With the enhancement of mitochondrial generation of reactive oxygen species by hyperoxia, oxidant injury was substantially enhanced in mitochondrial membranes, even in tissues distant from the lung. Hyperoxia, despite its vasodilatory actions in the pulmonary circulation, significantly worsened the PAH phenotype (elevated right ventricular systolic pressure, decreased cardiac output, and increased pulmonary vascular occlusion) in Bmpr2 mutant animals. These experiments demonstrate that oxidant injury and metabolic stress contribute directly to disease development, and provide further evidence for PAH as a systemic disease with life-limiting cardiopulmonary manifestations.
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Affiliation(s)
- Joshua P Fessel
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine
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108
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Abstract
Abnormalities in myocardial substrate metabolism play a central role in the manifestations of most forms of cardiac disease such as ischemic heart disease, heart failure, hypertensive heart disease, and the cardiomyopathy due to either obesity or diabetes mellitus. Their importance is exemplified by both the development of numerous imaging tools designed to detect the specific metabolic perturbations or signatures related to these different diseases, and the vigorous efforts in drug discovery/development targeting various aspects of myocardial metabolism. Since the prior review in 2005, we have gained new insights into how perturbations in myocardial metabolism contribute to various forms of cardiac disease. For example, the application of advanced molecular biologic techniques and the development of elegant genetic models have highlighted the pleiotropic actions of cellular metabolism on energy transfer, signal transduction, cardiac growth, gene expression, and viability. In parallel, there have been significant advances in instrumentation, radiopharmaceutical design, and small animal imaging, which now permit a near completion of the translational pathway linking in-vitro measurements of metabolism with the human condition. In this review, most of the key advances in metabolic imaging will be described, their contribution to cardiovascular research highlighted, and potential new clinical applications proposed.
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Affiliation(s)
- Robert J Gropler
- Division of Radiological Sciences, Cardiovascular Imaging Laboratory, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway, St. Louis, MO, 63110, USA,
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109
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Tonelli AR, Alkukhun L, Arelli V, Ramos J, Newman J, McCarthy K, Pichurko B, Minai OA, Dweik RA. Value of impedance cardiography during 6-minute walk test in pulmonary hypertension. Clin Transl Sci 2013; 6:474-80. [PMID: 24330692 PMCID: PMC4286797 DOI: 10.1111/cts.12090] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Methods that predict prognosis and response to therapy in pulmonary hypertension (PH) are lacking. We tested whether the noninvasive estimation of hemodynamic parameters during 6-minute walk test (6MWT) in PH patients provides information that can improve the value of the test. METHODS We estimated hemodynamic parameters during the 6MWT using a portable, signal-morphology-based, impedance cardiograph (PhysioFlow Enduro) with real-time wireless monitoring via a bluetooth USB adapter. RESULTS We recruited 48 subjects in the study (30 with PH and 18 healthy controls). PH patients had significantly lower maximum stroke volume (SV) and CI and slower cardiac output (CO) acceleration and decelerations slopes during the test when compared with healthy controls. In PH patients, CI change was associated with total distance walked (R = 0.62; P < 0.001) and percentage of predicted (R = 0.4, P = 0.03), HR recovery at 1 minute (0.57, P < 0.001), 2 minutes (0.65, P < 0.001), and 3 minutes (0.66, P < 0.001). Interestingly, in PH patients CO change during the test was predominantly related to an increase in SV instead of HR. CONCLUSIONS Estimation of hemodynamic parameters such as cardiac index during 6-minute walk test is feasible and may provide useful information in patients with PH. Clin Trans Sci 2013; Volume #: 1-7.
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Affiliation(s)
- Adriano R Tonelli
- Department of Pulmonary, Allergy and Critical Care Medicine, Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, USA
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110
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Goncharov DA, Kudryashova TV, Ziai H, Ihida-Stansbury K, DeLisser H, Krymskaya VP, Tuder RM, Kawut SM, Goncharova EA. Mammalian target of rapamycin complex 2 (mTORC2) coordinates pulmonary artery smooth muscle cell metabolism, proliferation, and survival in pulmonary arterial hypertension. Circulation 2013; 129:864-74. [PMID: 24270265 DOI: 10.1161/circulationaha.113.004581] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Enhanced proliferation, resistance to apoptosis, and metabolic shift to glycolysis of pulmonary arterial vascular smooth muscle cells (PAVSMCs) are key pathophysiological components of pulmonary vascular remodeling in idiopathic pulmonary arterial hypertension (PAH). The role of the distinct mammalian target of rapamycin (mTOR) complexes mTORC1 (mTOR-Raptor) and mTORC2 (mTOR-Rictor) in PAVSMC proliferation and survival in PAH and their therapeutic relevance are unknown. METHODS AND RESULTS Immunohistochemical and immunoblot analyses revealed that mTORC1 and mTORC2 pathways are markedly upregulated in small remodeled pulmonary arteries and isolated distal PAVSMCs from subjects with idiopathic PAH that have increased ATP levels, proliferation, and survival that depend on glycolytic metabolism. Small interfering RNA- and pharmacology-based analysis showed that although both mTORC1 and mTORC2 contribute to proliferation, only mTORC2 is required for ATP generation and survival of idiopathic PAH PAVSMCs. mTORC2 downregulated the energy sensor AMP-activated protein kinase, which led to activation of mTORC1-S6 and increased proliferation, as well as a deficiency of the proapoptotic protein Bim and idiopathic PAH PAVSMC survival. NADPH oxidase 4 (Nox4) protein levels were increased in idiopathic PAH PAVSMCs, which was necessary for mTORC2 activation, proliferation, and survival. Nox4 levels and mTORC2 signaling were significantly upregulated in small pulmonary arteries from hypoxia-exposed rats at days 2 to 28 of hypoxia. Treatment with the mTOR kinase inhibitor PP242 at days 15 to 28 suppressed mTORC2 but not Nox4, induced smooth muscle-specific apoptosis in small pulmonary arteries, and reversed hypoxia-induced pulmonary vascular remodeling in rats. CONCLUSIONS These data provide a novel mechanistic link of Nox4-dependent activation of mTORC2 via the energy sensor AMP-activated protein kinase to increased proliferation and survival of PAVSMCs in PAH, which suggests a new potential pathway for therapeutic interventions.
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Affiliation(s)
- Dmitry A Goncharov
- Pulmonary, Allergy & Critical Care Division (D.A.G., T.V.K., H.Z., H.D., V.P.K., S.M.K., E.A.G.), Department of Pathology and Laboratory Medicine (K.I.-S.), Pulmonary Vascular Disease Program (K.I.-S., H.D., V.P.K., S.M.K., E.A.G.), Center for Clinical Epidemiology and Biostatistics (S.M.K.), and Abramson Cancer Center (V.P.K.), Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA; Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, CO (R.M.T.); and Division of Pulmonary, Allergy and Critical Care Medicine, Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA (D.A.G., T.V.K.). Dr Goncharova's current affiliation is the Division of Pulmonary, Allergy and Critical Care Medicine, Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA
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111
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Ruiter G, Wong YY, Raijmakers P, Huisman MC, Lammertsma AA, Knaapen P, de Man FS, Westerhof N, van der Laarse WJ, Vonk-Noordegraaf A. Pulmonary 2-deoxy-2-[(18)F]-fluoro-d-glucose uptake is low in treated patients with idiopathic pulmonary arterial hypertension. Pulm Circ 2013; 3:647-53. [PMID: 24618549 DOI: 10.1086/674335] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract Glucose metabolism measurement using 2-deoxy-2-[(18)F]-fluoro-d-glucose ((18)FDG) positron emission tomography (PET) could provide in vivo information about pulmonary vascular remodeling. The purpose of this study was to assess whether pulmonary (18)FDG uptake in idiopathic pulmonary arterial hypertension (IPAH) patients changes and, if so, to determine whether the change is related to disease severity and survival. Sixteen IPAH patients who were treated with IPAH-specific therapy and 7 patients who had a myocardial infarction (MI) without pulmonary hypertension were included. IPAH disease severity was determined using the 6-minute walk test and right heart catheterization 2 days before (18)FDG PET. Regions of interest were defined for left and right lungs, and standardized uptake values (SUVs), normalized to body weight, injected dose, and plasma glucose level, were derived. Mean SUVs for IPAH left and right lungs were [Formula: see text] and [Formula: see text] ([Formula: see text]), respectively. In MI patients, SUVs were [Formula: see text] and [Formula: see text] ([Formula: see text]) in left and right lungs, respectively. Total lung SUVs were similar in IPAH and MI patients ([Formula: see text] vs. [Formula: see text]; [Formula: see text]). There was no correlation between SUV and IPAH disease severity parameters. In addition, lung SUV did not predict survival in IPAH patients (hazard ratio, 1.155; 95% confidence interval, 0.16-8.26; [Formula: see text]). In conclusion, pulmonary (18)FDG uptake in treated IPAH patients is low and is not associated with disease severity and survival, thereby limiting its clinical use in patient care.
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Affiliation(s)
- Gerrina Ruiter
- 1 Department of Pulmonology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
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112
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Cottrill KA, Chan SY. Metabolic dysfunction in pulmonary hypertension: the expanding relevance of the Warburg effect. Eur J Clin Invest 2013; 43:855-65. [PMID: 23617881 PMCID: PMC3736346 DOI: 10.1111/eci.12104] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 04/04/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Pulmonary hypertension (PH) is an enigmatic vascular syndrome characterized by increased pulmonary arterial pressure and adverse remodelling of the pulmonary arterioles and often of the right ventricle. Drawing parallels with tumourigenesis, recent endeavours have explored the relationship between metabolic dysregulation and PH pathogenesis. DESIGN We will discuss the general mechanisms by which cellular stressors such as hypoxia and inflammation alter cellular metabolism. Based on those principles, we will explore the development of a corresponding metabolic pathophenotype in PH, with a focus on WHO Groups I and III, and the implications that these alterations may have for future treatment of this disease. RESULTS Investigation of metabolic dysregulation in both the pulmonary vasculature and right ventricle during PH pathogenesis has provided a more unifying understanding of how disparate disease triggers coordinate end-stage disease manifestations. Namely, as defined originally in various cancers, the Warburg effect describes a chronic shift in energy production from mitochondrial oxidative phosphorylation to glycolysis. In many cases, this Warburg phenotype may serve as a central causative mechanism for PH progression, largely driving cellular hyperproliferation and resistance to apoptosis. Consequently, new therapeutic strategies have been increasingly pursued that target the Warburg phenotype. Finally, new technologies are increasingly becoming available to probe more completely the complexities of metabolic cellular reprogramming and may reveal distinct metabolic pathways beyond the Warburg effect that drive PH. CONCLUSION Studies of metabolic dysregulation in PH are just emerging but may offer powerful therapeutic means to prevent or even reverse disease progression at the molecular level.
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Affiliation(s)
- Katherine A Cottrill
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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113
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Zhao L, Ashek A, Wang L, Fang W, Dabral S, Dubois O, Cupitt J, Pullamsetti SS, Cotroneo E, Jones H, Tomasi G, Nguyen QD, Aboagye EO, El-Bahrawy MA, Barnes G, Howard LS, Gibbs JSR, Gsell W, He JG, Wilkins MR. Heterogeneity in lung (18)FDG uptake in pulmonary arterial hypertension: potential of dynamic (18)FDG positron emission tomography with kinetic analysis as a bridging biomarker for pulmonary vascular remodeling targeted treatments. Circulation 2013; 128:1214-24. [PMID: 23900048 DOI: 10.1161/circulationaha.113.004136] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is a disease of progressive vascular remodeling, characterized by dysregulated growth of pulmonary vascular cells and inflammation. A prevailing view is that abnormal cellular metabolism, notably aerobic glycolysis that increases glucose demand, underlies the pathogenesis of PAH. Increased lung glucose uptake has been reported in animal models. Few data exist from patients with PAH. METHODS AND RESULTS Dynamic positron emission tomography imaging with fluorine-18-labeled 2-fluoro-2-deoxyglucose ((18)FDG) ligand with kinetic analysis demonstrated increased mean lung parenchymal uptake in 20 patients with PAH, 18 with idiopathic PAH (IPAH) (FDG score: 3.27±1.22), and 2 patients with connective tissue disease (5.07 and 7.11) compared with controls (2.02±0.71; P<0.05). Further compartment analysis confirmed increased lung glucose metabolism in IPAH. Lung (18)FDG uptake and metabolism varied within the IPAH population and within the lungs of individual patients, consistent with the recognized heterogeneity of vascular pathology in this disease. The monocrotaline rat PAH model also showed increased lung (18)FDG uptake, which was reduced along with improvements in vascular pathology after treatment with dicholoroacetate and 2 tyrosine kinase inhibitors, imatinib and sunitinib. Hyperproliferative pulmonary vascular fibroblasts isolated from IPAH patients exhibited upregulated glycolytic gene expression, along with increased cellular (18)FDG uptake; both were reduced by dicholoroacetate and imatinib. CONCLUSIONS Some patients with IPAH exhibit increased lung (18)FDG uptake. (18)FDG positron emission tomography imaging is a tool to investigate the molecular pathology of PAH and its response to treatment.
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Affiliation(s)
- Lan Zhao
- Centre for Pharmacology and Therapeutics, Experimental Medicine, Imperial College London, Hammersmith Hospital, London, UK (L.Z., A.A., L.W., O.D., J.C., E.C., H.J., G.B., M.R.W.); Department of Nuclear Medicine, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (W.F.); Max-Planck Institute for Heart and Lung Research and University of Giessen and Marburg Lung Center, German Center for Lung Research, Bad Nauheim, Germany (S.D., S.S.P.); Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK (G.T., Q.N., E.O.A.); Department of Histopathology, Imperial College London, UK (M.A.E.-B.); National Heart and Lung Institute, Imperial College London, and National Pulmonary Hypertension Service, Department of Cardiology, Hammersmith Hospital, London, UK (L.S.H., J.S.R.G.); Biological Imaging Centre, Medical Research Council Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, UK (W.G.); and Center for Diagnosis and Management of Pulmonary Vascular Diseases, Department of Cardiology, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (J.H.)
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114
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Aliotta JM, Pereira M, Amaral A, Sorokina A, Igbinoba Z, Hasslinger A, El-Bizri R, Rounds SI, Quesenberry PJ, Klinger JR. Induction of pulmonary hypertensive changes by extracellular vesicles from monocrotaline-treated mice. Cardiovasc Res 2013; 100:354-62. [PMID: 23867631 DOI: 10.1093/cvr/cvt184] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Circulating endothelium-derived extracellular vesicles (EV) levels are altered in pulmonary arterial hypertension (PAH) but whether they are biomarkers of cellular injury or participants in disease pathogenesis is unknown. Previously, we found that lung-derived EVs (LEVs) induce bone marrow-derived progenitor cells to express lung-specific mRNA and protein. In this study, we sought to determine whether LEV or plasma-derived EV (PEV) alter pulmonary vascular endothelial or marrow progenitor cell phenotype to induce pulmonary vascular remodelling. METHODS AND RESULTS LEV, PEV isolated from monocrotaline (MCT-EV)- or vehicle-treated mice (vehicle-EV) were injected into healthy mice. Right ventricular (RV) hypertrophy and pulmonary vascular remodelling were assessed by RV-to-body weight (RV/BW) and blood vessel wall thickness-to-diameter (WT/D) ratios. RV/BW, WT/D ratios were elevated in MCT- vs. vehicle-injected mice (1.99 ± 0.09 vs. 1.04 ± 0.09 mg/g; 0.159 ± 0.002 vs. 0.062 ± 0.009%). RV/BW, WT/D ratios were higher in mice injected with MCT-EV vs. mice injected with vehicle-EV (1.63 ± 0.09 vs. 1.08 ± 0.09 mg/g; 0.113 ± 0.02 vs. 0.056 ± 0.01%). Lineage-depleted bone marrow cells incubated with MCT-EV and marrow cells isolated from mice infused with MCT-EV had greater expression of endothelial progenitor cell mRNAs and mRNAs abnormally expressed in PAH than cells incubated with vehicle-EV or isolated from vehicle-EV infused mice. MCT-EV induced an apoptosis-resistant phenotype in murine pulmonary endothelial cells and lineage-depleted bone marrow cells incubated with MCT-EV induced pulmonary hypertension when injected into healthy mice. CONCLUSIONS EV from MCT-injured mice contribute to the development of MCT-induced pulmonary hypertension. This effect may be mediated directly by EV on the pulmonary vasculature or by differentiation of bone marrow cells to endothelial progenitor cells that induce pulmonary vascular remodelling.
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Affiliation(s)
- Jason M Aliotta
- Division of Hematology/Oncology, Department of Medicine, Rhode Island Hospital, Providence, RI 02908, USA
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115
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Abstract
Pulmonary hypertension (PH) is the remarkable hemodynamic consequence of widespread structural and functional changes within the pulmonary circulation. Elevated pulmonary vascular resistance leads to increased mean pulmonary arterial pressure and, ultimately, right ventricular dysfunction. PH carries a poor prognosis and warrants timely and accurate diagnosis for appropriate intervention. The 2008 Dana Point classification system provides the categorical framework currently guiding therapy and surveillance. Radiologic imaging is an essential tool in the detection and diagnostic evaluation of patients with PH. Echocardiography, ventilation-perfusion scintigraphy, multidetector computed tomography, and cardiac magnetic resonance imaging provide insights into vascular morphology, pulmonary parenchymal status, cardiac function, and underlying etiology of the disorder. Emerging techniques of functional pulmonary and cardiac imaging hold great promise for the assessment and monitoring of these patients in the future.
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Affiliation(s)
- Aletta Ann Frazier
- Department of Diagnostic Radiology, University of Maryland Medical System, Baltimore, MD 21201, USA.
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116
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Sun X, Sharma S, Fratz S, Kumar S, Rafikov R, Aggarwal S, Rafikova O, Lu Q, Burns T, Dasarathy S, Wright J, Schreiber C, Radman M, Fineman JR, Black SM. Disruption of endothelial cell mitochondrial bioenergetics in lambs with increased pulmonary blood flow. Antioxid Redox Signal 2013; 18:1739-52. [PMID: 23244702 PMCID: PMC3619212 DOI: 10.1089/ars.2012.4806] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AIMS The mitochondrial dysfunction in our lamb model of congenital heart disease with increased pulmonary blood flow (PBF) (Shunt) is associated with disrupted carnitine metabolism. Our recent studies have also shown that asymmetric dimethylarginine (ADMA) levels are increased in Shunt lambs and ADMA increases the nitration of mitochondrial proteins in lamb pulmonary arterial endothelial cells (PAEC) in a nitric oxide synthase (NOS)-dependent manner. Thus, we determined whether there was a mechanistic link between endothelial nitric oxide synthase (eNOS), ADMA, and the disruption of carnitine homeostasis in PAEC. RESULTS Exposure of PAEC to ADMA induced the redistribution of eNOS to the mitochondria, resulting in an increase in carnitine acetyl transferase (CrAT) nitration and decreased CrAT activity. The resulting increase in acyl-carnitine levels resulted in mitochondrial dysfunction and the disruption of mitochondrial bioenergetics. Since the addition of L-arginine prevented these pathologic changes, we examined the effect of L-arginine supplementation on carnitine homeostasis, mitochondrial function, and nitric oxide (NO) signaling in Shunt lambs. We found that the treatment of Shunt lambs with L-arginine prevented the ADMA-mediated mitochondrial redistribution of eNOS, the nitration-mediated inhibition of CrAT, and maintained carnitine homeostasis. In turn, adenosine-5'-triphosphate levels and eNOS/heat shock protein 90 interactions were preserved, and this decreased NOS uncoupling and enhanced NO generation. INNOVATION Our data link alterations in cellular L-arginine metabolism with the disruption of mitochondrial bioenergetics and implicate altered carnitine homeostasis as a key player in this process. CONCLUSION L-arginine supplementation may be a useful therapy to prevent the mitochondrial dysfunction involved in the pulmonary vascular alterations secondary to increased PBF.
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Affiliation(s)
- Xutong Sun
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta, GA 30912, USA.
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117
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Methods for measuring right ventricular function and hemodynamic coupling with the pulmonary vasculature. Ann Biomed Eng 2013; 41:1384-98. [PMID: 23423705 DOI: 10.1007/s10439-013-0752-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 01/21/2013] [Indexed: 12/11/2022]
Abstract
The right ventricle (RV) is a pulsatile pump, the efficiency of which depends on proper hemodynamic coupling with the compliant pulmonary circulation. The RV and pulmonary circulation exhibit structural and functional differences with the more extensively investigated left ventricle (LV) and systemic circulation. In light of these differences, metrics of LV function and efficiency of coupling to the systemic circulation cannot be used without modification to characterize RV function and efficiency of coupling to the pulmonary circulation. In this article, we review RV physiology and mechanics, established and novel methods for measuring RV function and hemodynamic coupling, and findings from application of these methods to RV function and coupling changes with pulmonary hypertension. We especially focus on non-invasive measurements, as these may represent the future for clinical monitoring of disease progression and the effect of drug therapies.
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118
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Abstract
Genetically modified mouse models have unparalleled power to determine the mechanisms behind different processes involved in the molecular and physiologic etiology of various classes of human pulmonary hypertension (PH). Processes known to be involved in PH for which there are extensive mouse models available include the following: (1) Regulation of vascular tone through secreted vasoactive factors; (2) regulation of vascular tone through potassium and calcium channels; (3) regulation of vascular remodeling through alteration in metabolic processes, either through alteration in substrate usage or through circulating factors; (4) spontaneous vascular remodeling either before or after development of elevated pulmonary pressures; and (5) models in which changes in tone and remodeling are primarily driven by inflammation. PH development in mice is of necessity faster and with different physiologic ramifications than found in human disease, and so mice make poor models of natural history of PH. However, transgenic mouse models are a perfect tool for studying the processes involved in pulmonary vascular function and disease, and can effectively be used to test interventions designed against particular molecular pathways and processes involved in disease.
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Affiliation(s)
- Mita Das
- Department of Internal Medicine, University of Arkansas Medical Sciences, Little Rock, Arkansas, USA
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119
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Goncharova EA. mTOR and vascular remodeling in lung diseases: current challenges and therapeutic prospects. FASEB J 2013; 27:1796-807. [PMID: 23355268 DOI: 10.1096/fj.12-222224] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mammalian target of rapamycin (mTOR) is a major regulator of cellular metabolism, proliferation, and survival that is implicated in various proliferative and metabolic diseases, including obesity, type 2 diabetes, hamartoma syndromes, and cancer. Emerging evidence suggests a potential critical role of mTOR signaling in pulmonary vascular remodeling. Remodeling of small pulmonary arteries due to increased proliferation, resistance to apoptosis, and altered metabolism of cells forming the pulmonary vascular wall is a key currently irreversible pathological feature of pulmonary hypertension, a progressive pulmonary vascular disorder with high morbidity and mortality. In addition to rare familial and idiopathic forms, pulmonary hypertension is also a life-threatening complication of several lung diseases associated with hypoxia. This review aims to summarize our current knowledge and recent advances in understanding the role of the mTOR pathway in pulmonary vascular remodeling, with a specific focus on the hypoxia component, a confirmed shared trigger of pulmonary hypertension in lung diseases. We also discuss the emerging role of mTOR as a promising therapeutic target and mTOR inhibitors as potential pharmacological approaches to treat pulmonary vascular remodeling in pulmonary hypertension.
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Affiliation(s)
- Elena A Goncharova
- University of Pennsylvania Perelman School of Medicine, Translational Research Laboratories, Rm. 1214, 125 South 31st St., Philadelphia, PA 19104, USA.
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120
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Tuder RM, Lara AR, Thannickal VJ. Lactate, a novel trigger of transforming growth factor-β activation in idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 2012; 186:701-3. [PMID: 23071184 DOI: 10.1164/rccm.201208-1491ed] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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121
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White K, Loscalzo J, Chan SY. Holding our breath: The emerging and anticipated roles of microRNA in pulmonary hypertension. Pulm Circ 2012; 2:278-90. [PMID: 23130098 PMCID: PMC3487298 DOI: 10.4103/2045-8932.101395] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Over the past decade, the importance of non-coding RNA such as microRNA has been established in numerous processes that drive human pathogenesis. These crucial molecular regulators modulate networks of target gene transcripts that, in turn, orchestrate cellular phenotypes such as cell survival, differentiation, proliferation, and metabolism among others and thus affect cardiopulmonary vascular disease conditions. Many of these same pathophenotypes figure prominently in the complex pathogenesis of pulmonary hypertension, an enigmatic vascular disorder characterized by a histological panvasculopathy and driven by disparate upstream triggers such as hypoxia, inflammation, and bone morphogenetic protein signaling. Yet, the importance of just a few microRNAs in pulmonary hypertension has been recognized, and we are only beginning to understand the integrative functions of these molecules in this disease. By combining systems biology with traditional experimental approaches, more direct insight into the pleiotropy of microRNA should not only further reveal the spectrum of molecular pathways that cause pulmonary hypertension, but also offer novel and much needed diagnostic and therapeutic strategies.
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Affiliation(s)
- Kevin White
- Brigham and Women's Hospital, and Harvard Medical School, Boston, Massachusetts, USA
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122
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Gomez-Arroyo J, Mizuno S, Szczepanek K, Van Tassell B, Natarajan R, dos Remedios CG, Drake JI, Farkas L, Kraskauskas D, Wijesinghe DS, Chalfant CE, Bigbee J, Abbate A, Lesnefsky EJ, Bogaard HJ, Voelkel NF. Metabolic gene remodeling and mitochondrial dysfunction in failing right ventricular hypertrophy secondary to pulmonary arterial hypertension. Circ Heart Fail 2012; 6:136-44. [PMID: 23152488 DOI: 10.1161/circheartfailure.111.966127] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Right ventricular (RV) dysfunction (RVD) is the most frequent cause of death in patients with pulmonary arterial hypertension. Although abnormal energy substrate use has been implicated in the development of chronic left heart failure, data describing such metabolic remodeling in RVD remain incomplete. Thus, we sought to characterize metabolic gene expression changes and mitochondrial dysfunction in functional and dysfunctional RV hypertrophy. METHODS AND RESULTS Two different rat models of RV hypertrophy were studied. The model of RVD (SU5416/hypoxia) exhibited a significantly decreased gene expression of peroxisome proliferator-activated receptor-γ coactivator-1α, peroxisome proliferator-activated receptor-α and estrogen-related receptor-α. The expression of multiple peroxisome proliferator-activated receptor-γ coactivator-1α target genes required for fatty acid oxidation was similarly decreased. Decreased peroxisome proliferator-activated receptor-γ coactivator-1α expression was also associated with a net loss of mitochondrial protein and oxidative capacity. Reduced mitochondrial number was associated with a downregulation of transcription factor A, mitochondrial, and other genes required for mitochondrial biogenesis. Electron microscopy demonstrated that, in RVD tissue, mitochondria had abnormal shape and size. Lastly, respirometric analysis demonstrated that mitochondria isolated from RVD tissue had a significantly reduced ADP-stimulated (state 3) rate for complex I. Conversely, functional RV hypertrophy in the pulmonary artery banding model showed normal expression of peroxisome proliferator-activated receptor-γ coactivator-1α, whereas the expression of fatty acid oxidation genes was either preserved or unregulated. Moreover, pulmonary artery banding-RV tissue exhibited preserved transcription factor A mitochondrial expression and mitochondrial respiration despite elevated RV pressure-overload. CONCLUSIONS Right ventricular dysfunction, but not functional RV hypertrophy in rats, demonstrates a gene expression profile compatible with a multilevel impairment of fatty acid metabolism and significant mitochondrial dysfunction, partially independent of chronic pressure-overload.
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Affiliation(s)
- Jose Gomez-Arroyo
- Victoria Johnson Center for Lung Obstructive Disease Research, Virginia Commonwealth University, Richmond, VA 23298, USA
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123
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Pulmonary hypertension in parenchymal lung disease. Pulm Med 2012; 2012:684781. [PMID: 23094153 PMCID: PMC3474989 DOI: 10.1155/2012/684781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 09/07/2012] [Indexed: 01/23/2023] Open
Abstract
Idiopathic pulmonary arterial hypertension (IPAH) has been extensively investigated, although it represents a less common form of the pulmonary hypertension (PH) family, as shown by international registries. Interestingly, in types of PH that are encountered in parenchymal lung diseases such as interstitial lung diseases (ILDs), chronic obstructive pulmonary disease (COPD), and many other diffuse parenchymal lung diseases, some of which are very common, the available data is limited. In this paper, we try to browse in the latest available data regarding the occurrence, pathogenesis, and treatment of PH in chronic parenchymal lung diseases.
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124
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Current world literature. Curr Opin Rheumatol 2012; 24:694-702. [PMID: 23018859 DOI: 10.1097/bor.0b013e328359ee5b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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125
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Fessel JP, Hamid R, Wittmann BM, Robinson LJ, Blackwell T, Tada Y, Tanabe N, Tatsumi K, Hemnes AR, West JD. Metabolomic analysis of bone morphogenetic protein receptor type 2 mutations in human pulmonary endothelium reveals widespread metabolic reprogramming. Pulm Circ 2012; 2:201-13. [PMID: 22837861 PMCID: PMC3401874 DOI: 10.4103/2045-8932.97606] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a progressive and fatal disease of the lung vasculature for which the molecular etiologies are unclear. Specific metabolic alterations have been identified in animal models and in PAH patients, though existing data focus mainly on abnormalities of glucose homeostasis. We hypothesized that analysis of the entire metabolome in PAH would reveal multiple other metabolic changes relevant to disease pathogenesis and possible treatment. Layered transcriptomic and metabolomic analyses of human pulmonary microvascular endothelial cells (hPMVEC) expressing two different disease-causing mutations in the bone morphogenetic protein receptor type 2 (BMPR2) confirmed previously described increases in aerobic glycolysis but also uncovered significant upregulation of the pentose phosphate pathway, increases in nucleotide salvage and polyamine biosynthesis pathways, decreases in carnitine and fatty acid oxidation pathways, and major impairment of the tricarboxylic acid (TCA) cycle and failure of anaplerosis. As a proof of principle, we focused on the TCA cycle, predicting that isocitrate dehydrogenase (IDH) activity would be altered in PAH, and then demonstrating increased IDH activity not only in cultured hPMVEC expressing mutant BMPR2 but also in the serum of PAH patients. These results suggest that widespread metabolic changes are an important part of PAH pathogenesis, and that simultaneous identification and targeting of the multiple involved pathways may be a more fruitful therapeutic approach than targeting of any one individual pathway.
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Affiliation(s)
- Joshua P Fessel
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee, USA
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126
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Voelkel NF, Gomez-Arroyo J, Abbate A, Bogaard HJ, Nicolls MR. Pathobiology of pulmonary arterial hypertension and right ventricular failure. Eur Respir J 2012; 40:1555-65. [PMID: 22743666 DOI: 10.1183/09031936.00046612] [Citation(s) in RCA: 210] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pulmonary arterial hypertension (PAH) is no longer an orphan disease. There are three different classes of drugs for the treatment of PAH that are currently being used and an increasing number of patients are being treated with a single drug or combination therapy. During the last 25 yrs, new insights into the pathobiology of PAH have been gained. The classical mechanical concepts of pressure, flow, shear stress, right ventricle wall stress and impedance have been complemented with the new concepts of cell injury and repair and interactions of complex multicellular systems. Integrating these concepts will become critical as we design new medical therapies in order to change the prognosis of patients with these fatal diseases. This review intends to summarise recent pathobiological concepts of PAH and right ventricle failure mainly derived from human studies, which reflect the progress made in the understanding of this complex group of pulmonary vascular diseases.
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Affiliation(s)
- Norbert F Voelkel
- Dept of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA.
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