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Gonzalez-Candia A, Herrera EA. High Altitude Pregnancies and Vascular Dysfunction: Observations From Latin American Studies. Front Physiol 2021; 12:786038. [PMID: 34950057 PMCID: PMC8688922 DOI: 10.3389/fphys.2021.786038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/02/2021] [Indexed: 12/14/2022] Open
Abstract
An estimated human population of 170 million inhabit at high-altitude (HA, above 2,500 m). The potential pathological effects of HA hypobaric hypoxia during gestation have been the focus of several researchers around the world. The studies based on the Himalayan and Central/South American mountains are particularly interesting as these areas account for nearly 70% of the HA world population. At present, studies in human and animal models revealed important alterations in fetal development and growth at HA. Moreover, vascular responses to chronic hypobaria in the pregnant mother and her fetus may induce marked cardiovascular impairments during pregnancy or in the neonatal period. In addition, recent studies have shown potential long-lasting postnatal effects that may increase cardiovascular risk in individuals gestated under chronic hypobaria. Hence, the maternal and fetal adaptive responses to hypoxia, influenced by HA ancestry, are vital for a better developmental and cardiovascular outcome of the offspring. This mini-review exposes and discusses the main determinants of vascular dysfunction due to developmental hypoxia at HA, such as the Andean Mountains, at the maternal and fetal/neonatal levels. Although significant advances have been made from Latin American studies, this area still needs further investigations to reveal the mechanisms involved in vascular dysfunction, to estimate complications of pregnancy and postnatal life adequately, and most importantly, to determine potential treatments to prevent or treat the pathological effects of being developed under chronic hypobaric hypoxia.
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Affiliation(s)
- Alejandro Gonzalez-Candia
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Instituto de Ciencias de la Salud, Universidad de O'Higgins, Rancagua, Chile
| | - Emilio A Herrera
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
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2
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Gaikwad AV, Eapen MS, McAlinden KD, Chia C, Larby J, Myers S, Dey S, Haug G, Markos J, Glanville AR, Sohal SS. Endothelial to mesenchymal transition (EndMT) and vascular remodeling in pulmonary hypertension and idiopathic pulmonary fibrosis. Expert Rev Respir Med 2020; 14:1027-1043. [PMID: 32659128 DOI: 10.1080/17476348.2020.1795832] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible fibrotic disease associated with respiratory failure. The disease remains idiopathic, but repeated alveolar epithelium injury, disruption of alveolar-capillary integrity, abnormal vascular repair, and pulmonary vascular remodeling are considered possible pathogenic mechanisms. Also, the development of comorbidities such as pulmonary hypertension (PH) could further impact disease outcome, quality of life and survival rates in IPF. AREAS COVERED The current review provides a comprehensive literature survey of the mechanisms involved in the development and manifestations of IPF and their links to PH pathology. This review also provides the current understanding of molecular mechanisms that link the two pathologies and will specifically decipher the role of endothelial to mesenchymal transition (EndMT) along with the possible triggers of EndMT. The possibility of targeting EndMT as a therapeutic option in IPF is discussed. EXPERT OPINION With a steady increase in prevalence and mortality, IPF is no longer considered a rare disease. Thus, it is of utmost importance and urgency that the underlying profibrotic pathways and mechanisms are fully understood, to enable the development of novel therapeutic strategies.
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Affiliation(s)
- Archana Vijay Gaikwad
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia
| | - Mathew Suji Eapen
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia
| | - Kielan D McAlinden
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia
| | - Collin Chia
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia.,Department of Respiratory Medicine, Launceston General Hospital , Launceston, Australia
| | - Josie Larby
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia.,Department of Respiratory Medicine, Launceston General Hospital , Launceston, Australia
| | - Stephen Myers
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia
| | - Surajit Dey
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia
| | - Greg Haug
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia.,Department of Respiratory Medicine, Launceston General Hospital , Launceston, Australia
| | - James Markos
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia.,Department of Respiratory Medicine, Launceston General Hospital , Launceston, Australia
| | - Allan R Glanville
- Lung Transplant Unit, Department of Thoracic Medicine, St Vincent's Hospital , Sydney, Australia
| | - Sukhwinder Singh Sohal
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania , Launceston, Australia
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3
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Marshall JD, Bazan I, Zhang Y, Fares WH, Lee PJ. Mitochondrial dysfunction and pulmonary hypertension: cause, effect, or both. Am J Physiol Lung Cell Mol Physiol 2018; 314:L782-L796. [PMID: 29345195 DOI: 10.1152/ajplung.00331.2017] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Pulmonary hypertension describes a heterogeneous disease defined by increased pulmonary artery pressures, and progressive increase in pulmonary vascular resistance due to pathologic remodeling of the pulmonary vasculature involving pulmonary endothelial cells, pericytes, and smooth muscle cells. This process occurs under various conditions, and although these populations vary, the clinical manifestations are the same: progressive dyspnea, increases in right ventricular (RV) afterload and dysfunction, RV-pulmonary artery uncoupling, and right-sided heart failure with systemic circulatory collapse. The overall estimated 5-yr survival rate is 72% in highly functioning patients, and as low as 28% for those presenting with advanced symptoms. Metabolic theories have been suggested as underlying the pathogenesis of pulmonary hypertension with growing evidence of the role of mitochondrial dysfunction involving the major proteins of the electron transport chain, redox-related enzymes, regulators of the proton gradient and calcium homeostasis, regulators of apoptosis, and mitophagy. There remain more studies needed to characterize mitochondrial dysfunction leading to impaired vascular relaxation, increase proliferation, and failure of regulatory mechanisms. The effects on endothelial cells and resulting interactions with their microenvironment remain uncharted territory for future discovery. Additionally, on the basis of observations that the "plexigenic lesions" of pulmonary hypertension resemble the unregulated proliferation of tumor cells, similarities between cancer pathobiology and pulmonary hypertension have been drawn, suggesting interactions between mitochondria and angiogenesis. Recently, mitochondria targeting has become feasible, which may yield new therapeutic strategies. We present a state-of-the-art review of the role of mitochondria in both the pathobiology of pulmonary hypertension and potential therapeutic targets in pulmonary vascular processes.
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Affiliation(s)
- Jeffrey D Marshall
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Isabel Bazan
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Yi Zhang
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Wassim H Fares
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Patty J Lee
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
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4
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Mishra A, Mohammad G, Norboo T, Newman JH, Pasha MAQ. Lungs at high-altitude: genomic insights into hypoxic responses. J Appl Physiol (1985) 2015; 119:1-15. [DOI: 10.1152/japplphysiol.00513.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 04/20/2015] [Indexed: 11/22/2022] Open
Abstract
Hypobaric hypoxia at high altitude (HA) results in reduced blood arterial oxygen saturation, perfusion of organs with hypoxemic blood, and direct hypoxia of lung tissues. The pulmonary complications in the cells of the pulmonary arterioles due to hypobaric hypoxia are the basis of the pathophysiological mechanisms of high-altitude pulmonary edema (HAPE). Some populations that have dwelled at HA for thousands of years have evolutionarily adapted to this environmental stress; unadapted populations may react with excessive physiological responses that impair health. Individual variations in response to hypoxia and the mechanisms of HA adaptation provide insight into physiological responses. Adaptive and maladaptive responses include alterations in pathways such as oxygen sensing, hypoxia signaling, K+- and Ca2+-gated channels, redox balance, and the renin-angiotensin-aldosterone system. Physiological imbalances are linked with genetic susceptibilities, and nonhomeostatic responses in gene regulation that occur by small RNAs, histone modification, and DNA methylation predispose susceptible humans to these HA illnesses. Elucidation of the interaction of these factors will lead to a more comprehensive understanding of HA adaptations and maladaptations and will lead to new therapeutics for HA disorders related to hypoxic lungs.
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Affiliation(s)
- Aastha Mishra
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Department of Biotechnology, University of Pune, Pune, India
| | - Ghulam Mohammad
- Department of Medicine, SNM Hospital, Leh, Ladakh, J&K, India
| | - Tsering Norboo
- Ladakh Institute of Prevention, Leh, Ladakh, J&K, India; and
| | - John H. Newman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - M. A. Qadar Pasha
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
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5
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[Pulmonary hypertension associated with congenital heart disease and Eisenmenger syndrome]. ARCHIVOS DE CARDIOLOGIA DE MEXICO 2015; 85:32-49. [PMID: 25650280 DOI: 10.1016/j.acmx.2014.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 11/24/2022] Open
Abstract
Pulmonary arterial hypertension is a common complication of congenital heart disease (CHD). Congenital cardiopathies are the most frequent congenital malformations. The prevalence in our country remains unknown, based on birthrate, it is calculated that 12,000 to 16,000 infants in our country have some cardiac malformation. In patients with an uncorrected left-to-right shunt, increased pulmonary pressure leads to vascular remodeling and endothelial dysfunction secondary to an imbalance in vasoactive mediators which promotes vasoconstriction, inflammation, thrombosis, cell proliferation, impaired apotosis and fibrosis. The progressive rise in pulmonary vascular resistance and increased pressures in the right heart provocated reversal of the shunt may arise with the development of Eisenmenger' syndrome the most advanced form de Pulmonary arterial hypertension associated with congenital heart disease. The prevalence of Pulmonary arterial hypertension associated with CHD has fallen in developed countries in recent years that is not yet achieved in developing countries therefore diagnosed late as lack of hospital infrastructure and human resources for the care of patients with CHD. With the development of targeted medical treatments for pulmonary arterial hypertension, the concept of a combined medical and interventional/surgical approach for patients with Pulmonary arterial hypertension associated with CHD is a reality. We need to know the pathophysiological factors involved as well as a careful evaluation to determine the best therapeutic strategy.
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Pasha Q. Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Genetics of pulmonary hypertension. Ann Thorac Med 2014; 9:S16-20. [PMID: 25076992 PMCID: PMC4114274 DOI: 10.4103/1817-1737.134009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 04/05/2014] [Indexed: 12/19/2022] Open
Abstract
Pulmonary hypertension (PH) is a phenotype characterized by functional and structural changes in the pulmonary vasculature, leading to increased vascular resistance.[12] The World Health Organization has classified PH into five different types: arterial, venous, hypoxic, thromboembolic or miscellaneous; details are available in the main guidelines. Group I of this classification, designated as pulmonary arterial hypertension (PAH), will remain the main focus here. The pathophysiology involves signaling, endothelial dysfunction, activation of fibroblasts and smooth muscle cells, interaction between cells within the vascular wall, and the circulating cells; as a consequence plexiform lesions are formed, which is common to both idiopathic and heritable PAH but are also seen in other forms of PAH.[234] As the pathology of PAH in the lung is well known, this article focuses on the genetic aspects associated with the disease and is a gist of several available articles in literature.
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Affiliation(s)
- Qadar Pasha
- Department of Genetics, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
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Zavadovsky KV, Krivonogov NG, Lishmanov YB. The usefulness of gated blood pool scintigraphy for right ventricular function evaluation in pulmonary embolism patients. Ann Nucl Med 2014; 28:632-7. [PMID: 24903244 DOI: 10.1007/s12149-014-0861-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 05/02/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE According to the international registry ICOPER, right ventricular (RV) dysfunction is the most significant predictor of mortality in patients with pulmonary embolism (PE). AIM To identify the most informative indicators of gated blood pool single photon emission computer tomography (GBP-SPECT) for evaluation of RV function in patients with PE. METHODS A total of 52 patients were included in the study. The main group (n = 37) comprised patients with PE, and the comparison group (n = 15) patients suffering from coronary heart disease (NYHA class I-II). All patients received GBP-SPECT, and assessment of plasma levels of endothelin-1, stable nitric oxide (NO) metabolites, and 6-keto-PG F1α. RESULTS In patients with PE, RV end-systolic volume, stroke volume, ejection fraction, peak ejection rate, peak filling rate, and mean filling rate were significantly lower in comparison with patients without PE. In patients with PE, the levels of endothelin-1, 6-keto-PG F1α, and stable NO metabolites were increased in comparison with patients without PE. CONCLUSIONS GBP-SPECT facilitates verification of RV dysfunction in patients without massive PE or severe pulmonary hypertension. Dissociation between the volume of PE and degree of RV dysfunction may be caused by an unbalance between humoral vasoactive factors.
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Affiliation(s)
- Konstantin V Zavadovsky
- Nuclear Medicine Department, Federal State Budgetary Institution "Research Institute for Cardiology" of Siberian Branch under the Russian Academy of Medical Science, 111a Kievskaya Str., Tomsk, 634012, Russia,
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Hohenforst-Schmidt W, Zarogoulidis P, Oezkan F, Mahnkopf C, Grabenbauer G, Kreczy A, Bartunek R, Darwiche K, Freitag L, Li Q, Huang H, Vogl T, Lepilvert P, Tsiouda T, Tsakiridis K, Zarogoulidis K, Brachmann J. "Denervation" of autonomous nervous system in idiopathic pulmonary arterial hypertension by low-dose radiation: a case report with an unexpected outcome. Ther Clin Risk Manag 2014; 10:207-15. [PMID: 24707181 PMCID: PMC3972028 DOI: 10.2147/tcrm.s58705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Vasointestinal peptide metabolism plays a key physiological role in multimodular levels of vasodilatory, smooth muscle cell proliferative, parenchymal, and inflammatory lung reactions. In animal studies, vasointestinal peptide relaxes isolated pulmonary arterial segments from several mammalian species in vitro and neutralizes the pulmonary vasoconstrictor effect of endothelin. In some animal models, it reduces pulmonary vascular resistance in vivo and in monocrotaline-induced pulmonary hypertension. A 58-year-old woman presented with dyspnea and mild edema of the lower extremities. A bronchoscopy was performed without any suspicious findings suggesting a central tumor or other infiltrative disease. Endobronchial ultrasound revealed enlarged pulmonary arteries containing thrombi, a few enlarged lymph nodes, and enlarged mediastinal tissue anatomy with suspicion for mediastinal infiltration of a malignant process. We estimated that less than 10% of the peripheral vascular bed of the lung was involved in direct consolidated fibrosis as demonstrated in the left upper lobe apex. Further, direct involvement of fibrosis around the main stems of the pulmonary arteries was assumed to be low from positron emission tomography and magnetic resonance imaging scans. Assuming a positive influence of low-dose radiation, it was not expected that this could have reduced pulmonary vascular resistance by over two thirds of the initial result. However; it was noted that this patient had idiopathic pulmonary arterial hypertension mixed with “acute” (mediastinal) fibrosis which could have contributed to the unexpected success of reduction of pulmonary vascular resistance. To the best of our knowledge, this is the first report of successful treatment of idiopathic pulmonary arterial hypertension, probably as a result of low-dose radiation to the pulmonary arterial main stems. The patient continues to have no specific complaints concerning her idiopathic pulmonary arterial hypertension.
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Affiliation(s)
| | - Paul Zarogoulidis
- Pulmonary Department-oncology Unit, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Filiz Oezkan
- Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Christian Mahnkopf
- II Medizinische Klinik, Klinik für Kardiologie, Angiologie, Pneumologie, Klinikum Coburg, Germany
| | | | - Alfons Kreczy
- Department of Pathology, Cytology and Molecular Diagnostics, University of Wüerzburg, Coburg, Germany
| | - Rudolf Bartunek
- Institute of Diagnostic and Interventional Radiology, Coburg Clinic, University of Wüerzburg, Coburg, Germany
| | - Kaid Darwiche
- Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Lutz Freitag
- Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Qiang Li
- Department of Respiratory Diseases, Changhai Hospital/First Affiliated Hospital of the Second Military Medical University, Shanghai, People's Republic of China
| | - Haidong Huang
- Department of Respiratory Diseases, Changhai Hospital/First Affiliated Hospital of the Second Military Medical University, Shanghai, People's Republic of China
| | - Thomas Vogl
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Frankfurt, Germany
| | - Patrick Lepilvert
- Interventional Drug Delivery Systems and Strategies (ID2S2), Medical Cryogenics, Lakeland Court Jupiter, FL, USA
| | - Theodora Tsiouda
- Internal Medicine Unit, Theagenio Cancer Hospital, Thessaloniki, Greece
| | - Kosmas Tsakiridis
- Cardiothoracic Surgery Department, Saint Luke Private Hospital, Thessaloniki, Greece
| | - Konstantinos Zarogoulidis
- Pulmonary Department-oncology Unit, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Johannes Brachmann
- II Medical Clinic, Coburg Clinic, University of Würzburg, Coburg, Germany
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Martin YN, Pabelick CM. Sex differences in the pulmonary circulation: implications for pulmonary hypertension. Am J Physiol Heart Circ Physiol 2014; 306:H1253-64. [PMID: 24610923 DOI: 10.1152/ajpheart.00857.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Pulmonary arterial hypertension (PAH), a form of pulmonary hypertension, is a complex disease of multifactorial origin. While new developments regarding pathophysiological features and therapeutic options in PAH are being reported, one important fact has emerged over the years: there is a sex difference in the incidence of this disease such that while there is a higher incidence in females, disease outcomes are much worse in males. Accordingly, recent attention has been focused on understanding the features of sex differences in the pulmonary circulation and the contributory mechanisms, particularly sex hormones and their role in the pathological and pathophysiological features of PAH. However, to date, there is no clear consensus whether sex hormones (particularly female sex steroids) are beneficial or detrimental in PAH. In this review, we highlight some of the most recent evidence regarding the influence of sex hormones (estrogen, testosterone, progesterone, dehydroepiandrosterone) and estrogen metabolites on key pathophysiological features of PAH such as proliferation, vascular remodeling, vasodilation/constriction, and inflammation, thus setting the stage for research avenues to identify novel therapeutic target for PAH as well as potentially other forms of pulmonary hypertension.
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Affiliation(s)
- Yvette N Martin
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
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Tajsic T, Morrell NW. Smooth muscle cell hypertrophy, proliferation, migration and apoptosis in pulmonary hypertension. Compr Physiol 2013; 1:295-317. [PMID: 23737174 DOI: 10.1002/cphy.c100026] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pulmonary hypertension is a multifactorial disease characterized by sustained elevation of pulmonary vascular resistance (PVR) and pulmonary arterial pressure (PAP). Central to the pathobiology of this disease is the process of vascular remodelling. This process involves structural and functional changes to the normal architecture of the walls of pulmonary arteries (PAs) that lead to increased muscularization of the muscular PAs, muscularization of the peripheral, previously nonmuscular, arteries of the respiratory acinus, formation of neointima, and formation of plexiform lesions. Underlying or contributing to the development of these lesions is hypertrophy, proliferation, migration, and resistance to apoptosis of medial cells and this article is concerned with the cellular and molecular mechanisms of these processes. In the first part of the article we focus on the concept of smooth muscle cell phenotype and the difficulties surrounding the identification and characterization of the cell/cells involved in the remodelling of the vessel media and we review the general mechanisms of cell hypertrophy, proliferation, migration and apoptosis. Then, in the larger part of the article, we review the factors identified thus far to be involved in PH intiation and/or progression and review and discuss their effects on pulmonary artery smooth muscle cells (PASMCs) the predominant cells in the tunica media of PAs.
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Affiliation(s)
- Tamara Tajsic
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
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11
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Yin J, Wang L, Yin N, Tabuchi A, Kuppe H, Wolff G, Kuebler WM. Vasodilatory effect of the stable vasoactive intestinal peptide analog RO 25-1553 in murine and rat lungs. PLoS One 2013; 8:e75861. [PMID: 24069452 PMCID: PMC3777882 DOI: 10.1371/journal.pone.0075861] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 08/23/2013] [Indexed: 11/18/2022] Open
Abstract
Rationale Stable analogs of vasoactive intestinal peptide (VIP) have been proposed as novel line of therapy in chronic obstructive pulmonary disease (COPD) based on their bronchodilatory and anti-inflammatory effects. We speculated that VIP analogs may provide additional benefits in that they exert vasodilatory properties in the lung, and tested this hypothesis in both ex vivo and in vivo models. Methods In isolated perfused mouse lungs and in an in vivo rat model, pulmonary blood vessels were preconstricted by hypoxia and hemodynamic changes in response to systemic (ex vivo) or inhaled (in vivo) administration of the cyclic VIP analog RO 25-1553 were determined. Results In mouse lungs, RO 25-1553 reduced intrinsic vascular resistance at normoxia, and attenuated the increase in pulmonary artery pressure in response to acute hypoxia. Consistently, inhalation of RO 25-1553 (1 mg·mL−1 for 3 min) caused an extensive and sustained (> 60 min) inhibition of the pulmonary arterial pressure increase in response to hypoxia in vivo that was comparable to the effects of inhaled sildenafil. This effect was not attributable to systemic cardiovascular effects of RO 25-1553, but to a lung specific reduction in pulmonary vascular resistance, while cardiac output and systemic arterial hemodynamics remained unaffected. No adverse effects of RO 25-1553 inhalation on pulmonary gas exchange, ventilation-perfusion matching, or lung fluid content were detected. Conclusion Our findings demonstrate that inhaled delivery of the stable VIP analog RO 25-1553 induces a potent and sustained vasodilatory effect in the pulmonary circulation with no detectable adverse effects. Therapeutic inhalation of RO 25-1553 may provide vascular benefits in addition to its reported anti-inflammatory and bronchodilatory effects in COPD, yet caution is warranted given the overall poor results of vasodilator therapies for pulmonary hypertension secondary to COPD in a series of recent clinical trials.
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Affiliation(s)
- Jun Yin
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
- The Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Institute for Anesthesiology, German Heart Institute, Berlin, Berlin, Germany
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Liming Wang
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
- The Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Institute for Anesthesiology, German Heart Institute, Berlin, Berlin, Germany
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ning Yin
- Institute for Anesthesiology, German Heart Institute, Berlin, Berlin, Germany
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Arata Tabuchi
- The Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Hermann Kuppe
- Institute for Anesthesiology, German Heart Institute, Berlin, Berlin, Germany
| | - Gerhard Wolff
- Department of Translational Medicine, Hoffmann-La Roche Ltd., Nutley, New York, United States of America
| | - Wolfgang M. Kuebler
- The Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Institute for Anesthesiology, German Heart Institute, Berlin, Berlin, Germany
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Departments of Surgery and Physiology, University of Toronto, Ontario, Canada
- * E-mail:
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Luo L, Liu D, Tang C, Du J, Liu AD, Holmberg L, Jin H. Sulfur dioxide upregulates the inhibited endogenous hydrogen sulfide pathway in rats with pulmonary hypertension induced by high pulmonary blood flow. Biochem Biophys Res Commun 2013; 433:519-25. [PMID: 23524260 DOI: 10.1016/j.bbrc.2013.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 03/06/2013] [Indexed: 11/20/2022]
Abstract
Pulmonary hypertension (PH) is an important pathophysiological process in the development of many diseases. However, the mechanism responsible for the development of PH remains unknown. The objective of the study was to explore the possible impact of sulfur dioxide (SO2) on the endogenous hydrogen sulfide (H2S) pathway in rats with PH induced by high pulmonary blood flow. Compared with sham group, the systolic pulmonary artery pressure (SPAP) in the shunt group was significantly increased, along with the increased percentage of muscularized arteries and partially muscularized arteries of small pulmonary arteries. Compared with the shunt group, SPAP in the shunt+SO2 group was significantly decreased, and the percentage of muscularized pulmonary arteries was also decreased. Additionally, rats that developed PH had significantly lower levels of SO2 concentration, aspartate aminotransferase (AAT) activity, protein and mRNA expressions of AAT2 in pulmonary tissues. Administration of an SO2 donor could alleviate the elevated pulmonary arterial pressure and decrease the muscularization of pulmonary arteries. At the same time, it increased the H2S production, protein expression of cystathionine-γ-lyase (CSE), mRNA expression of CSE, mercaptopyruvate transsulphurase (MPST) and cystathionine-β-synthase (CBS) in the pulmonary tissue of the rats. The results suggested that endogenous SO2/AAT2 pathway and the endogenous H2S production were downregulated in rats with PH induced by high pulmonary blood flow. However, SO2 could reduce pulmonary arterial pressure and improve the pulmonary vascular pathological changes in association with upregulating endogenous H2S pathway.
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Affiliation(s)
- Liman Luo
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
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Parekh H, Nguyen H, Hall S, Rehage M, Anholm J, Specht L, Linkhart T. Direct Pro-Inflammatory Effect of C-Reactive Protein on Human Pulmonary Artery Endothelial Cells. EUR J INFLAMM 2012. [DOI: 10.1177/1721727x1201000311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
C-reactive protein (CRP) has a prognostic role in cardiovascular and pulmonary diseases. Recent data suggest its pro-inflammatory effects in atherosclerotic lesion formation. This raises the hypothesis of whether or not CRP has pro-inflammatory effects on pulmonary vasculature by inducing the production of endothelin-1 (ET)-1, a potent vasoconstrictor and proliferative cytokine, and expression of adhesion molecules which could culminate in inflammatory cell recruitment and vascular injury. Human pulmonary artery endothelial cells (HPAECs) were cultured and incubated with 25μg/ml of human recombinant CRP and with interleukin (IL)-1β 10ng/ml, a well-known activator of endothelial cells, which served as a positive control for 24 hours. Expression of vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1 was assessed by flow cytometry. Secretion of ET-1 from HPAECs was also evaluated. In this study we show that incubation of HPAECs with human recombinant CRP for 24 hours induced a significant increase in ICAM-1 expression (from 610 to 6553 mean fluorescence intensity, p < 0.005) and VCAM-1 expression (from 212 to 303 mean fluorescence intensity, p < 0.05), as compared to control. Adhesion molecule induction was similar to that observed in endothelial cells activated with IL-1β. Likewise, CRP potentiated the ET-1 production by HPAECs. The levels of ET-1 were significantly higher at 24 hours (control 19.94±3 vs CRP 46.54±18 pg/ml, p < 0.05). In conclusion, this study makes a novel observation that CRP induces expression of adhesion molecules and secretion of ET-1 in HPAECs. Our study provides the first evidence that CRP exerts direct proinflammatory effects on pulmonary artery endothelial cells.
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Affiliation(s)
- H.J. Parekh
- Medical Service, Pulmonary and Critical Care Section, VA Loma Linda Healthcare System, Loma Linda, California, USA
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - H.B. Nguyen
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Loma Linda University School of Medicine, Loma Linda, California, USA
- Department of Emergency Medicine, Loma Linda University, Loma Linda, California, USA
| | - S.L. Hall
- Department of Medicine, VA Loma Linda Healthcare System and Loma Linda University School of Medicine, Loma Linda, California, USA
| | - M. Rehage
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, California, USA
| | - J. Anholm
- Medical Service, Pulmonary and Critical Care Section, VA Loma Linda Healthcare System, Loma Linda, California, USA
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - L. Specht
- Medical Service, Pulmonary and Critical Care Section, VA Loma Linda Healthcare System, Loma Linda, California, USA
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - T.A. Linkhart
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, California, USA
- Departments of Pediatrics and Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
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Yigitaslan S, Sirmagul B. Relation of bosentan, iloprost, and sildenafil with growth factor levels in monocrotaline-induced pulmonary hypertension. Clin Exp Hypertens 2012; 34:222-9. [PMID: 22468718 DOI: 10.3109/10641963.2011.631652] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
It is believed that growth factors play an important role in vascular remodeling that is evident in pulmonary hypertension (PH) pathogenesis. In the present study, the vascular endothelial growth factor (VEGF) levels in serum and pulmonary artery samples of rats have been analyzed with monocrotaline (MCT)-induced PH after treatments with iloprost, bosentan, and sildenafil. Serum VEGF and pulmonary artery VEGF levels were found to be significantly lower in MCT groups compared with control groups and significantly higher in treatment groups compared with MCT groups. In conclusion, treatment strategies directed at increasing VEGF levels may be reasonable in PH management.
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Affiliation(s)
- Semra Yigitaslan
- Department of Pharmacology, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey.
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15
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Hamidi SA, Lin RZ, Szema AM, Lyubsky S, Jiang YP, Said SI. VIP and endothelin receptor antagonist: an effective combination against experimental pulmonary arterial hypertension. Respir Res 2011; 12:141. [PMID: 22029879 PMCID: PMC3210095 DOI: 10.1186/1465-9921-12-141] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 10/26/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pulmonary Arterial Hypertension (PAH) remains a therapeutic challenge, and the search continues for more effective drugs and drug combinations. We recently reported that deletion of the vasoactive intestinal peptide (VIP) gene caused the spontaneous expression of a PH phenotype that was fully corrected by VIP. The objectives of this investigation were to answer the questions: 1) Can VIP protect against PH in other experimental models? and 2) Does combining VIP with an endothelin (ET) receptor antagonist bosentan enhance its efficacy? METHODS Within 3 weeks of a single injection of monocrotaline (MCT, s.c.) in Sprague Dawley rats, PAH developed, manifested by pulmonary vascular remodeling, lung inflammation, RV hypertrophy, and death within the next 2 weeks. MCT-injected animals were either untreated, treated with bosentan (p.o.) alone, with VIP (i.p.) alone, or with both together. We selected this particular combination upon finding that VIP down-regulates endothelin receptor expression which is further suppressed by bosentan. Therapeutic outcomes were compared as to hemodynamics, pulmonary vascular pathology, and survival. RESULTS Treatment with VIP, every other day for 3 weeks, begun on the same day as MCT, almost totally prevented PAH pathology, and eliminated mortality for 45 days. Begun 3 weeks after MCT, however, VIP only partially reversed PAH pathology, though more effectively than bosentan. Combined therapy with both drugs fully reversed the pathology, while preventing mortality for at least 45 days. CONCLUSIONS 1) VIP completely prevented and significantly reversed MCT-induced PAH; 2) VIP was more effective than bosentan, probably because it targets a wider range of pro-remodeling pathways; and 3) combination therapy with VIP plus bosentan was more effective than either drug alone, probably because both drugs synergistically suppressed ET-ET receptor pathway.
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Affiliation(s)
- Sayyed A Hamidi
- Department of Medicine, State University of New York at Stony Brook, NY, USA
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17
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Gupta RK, Vaideeswar P. Nitric oxide synthase 3 and endothelin 1 immunoreactivity in pulmonary hypertension. INDIAN J PATHOL MICR 2010; 53:447-50. [PMID: 20699500 DOI: 10.4103/0377-4929.68270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
CONTEXT Pulmonary hypertension (PH) is a serious and sometimes life-threatening event that occurs as a complication of various cardiopulmonary disorders, of which rheumatic heart disease (RHD) is an important example in our country. The pathogenesis of PH is a complex, multistep process in which "pulmonary endothelial dysfunction" (PED) is widely regarded as the central pathogenetic event. PED is, in turn, influenced by several local and systemic factors, of which nitric oxide synthase 3 (NOS3) and endothelin 1 (ET1) are 2 prime candidates, and are the subject of our study. AIMS Our aim was to study the immunoreactivity of NOS3 and ET1 in the pulmonary vasculature of PH patients of various etiologies, with emphasis on RHD cases. SETTINGS AND DESIGN A retrospective, autopsy-based study. SUBJECTS AND METHODS A total of 49 autopsy cases (39 patients and 10 controls) were chosen for our study. Of the 39 patients, 20 had PH secondary to RHD, whereas the remaining 19 patients had non-RHD etiologies as the basis of their PH. Lung sections taken from all the 49 cases were subjected to routine H and E, elastic van Gieson, and immunohistochemical staining (with NOS3 and ET1 separately). The intensity of immunostaining in all the cases and controls were then graded as focal/diffuse and weak/strong. RESULTS Controls showed positivity for both NOS3 (bronchiolar epithelium) and ET1 (endothelium of pulmonary arteries). Characteristic changes of PH on H and E were seen in 14 out of 19 non-RHD cases, which matched with the number of ET1 positivity cases. Similarly, for the RHD cases, 14 out of 20 cases showed changes of PH on H and E, but only 2 cases showed mild, focal positivity for ET1. Surprisingly, NOS3 positivity was largely absent in both the non-RHD and RHD cases. CONCLUSIONS Our study showed NOS3 negativity and ET1 positivity in the lung vasculature of patients with PH, a conclusion more or less in line with the predominant view of the other investigators in this field. But at the same time, our study could not conclude an unequivocal role of NOS3 in PH, whereas it could, in the case of ET1.
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Affiliation(s)
- Rajib K Gupta
- Department of Pathology, Seth GS Medical College & KEM Hospital, Mumbai, India
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18
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Wick MJ, Buesing EJ, Wehling CA, Loomis ZL, Cool CD, Zamora MR, Miller YE, Colgan SP, Hersh LB, Voelkel NF, Dempsey EC. Decreased neprilysin and pulmonary vascular remodeling in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2010; 183:330-40. [PMID: 20813891 DOI: 10.1164/rccm.201002-0154oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
RATIONALE Studies with genetically engineered mice showed that decreased expression of the transmembrane peptidase neprilysin (NEP) increases susceptibility to hypoxic pulmonary vascular remodeling and hypertension; in hypoxic wild-type mice, expression is decreased early in distal pulmonary arteries, where prominent vascular remodeling occurs. Therefore, in humans with smoke- and hypoxia-induced vascular remodeling, as in chronic obstructive pulmonary disease (COPD), pulmonary activity/expression of NEP may likewise be decreased. OBJECTIVES To test whether NEP activity and expression are reduced in COPD lungs and pulmonary arterial smooth muscle cells (SMCs) exposed to cigarette smoke extract or hypoxia and begin to investigate mechanisms involved. METHODS Control and advanced COPD lung lysates (n = 13-14) were analyzed for NEP activity and protein and mRNA expression. As a control, dipeptidyl peptidase IV activity was analyzed. Lung sections were assessed for vascular remodeling and oxidant damage. Human pulmonary arterial SMCs were exposed to cigarette smoke extract, hypoxia, or H₂O₂, and incubated with antioxidants or lysosomal/proteasomal inhibitors. MEASUREMENTS AND MAIN RESULTS COPD lungs demonstrated areas of vascular rarification, distal muscularization, and variable intimal and prominent medial/adventitial thickening. NEP activity was reduced by 76%; NEP protein expression was decreased in alveolar walls and distal vessels; mRNA expression was also decreased. In SMCs exposed to cigarette smoke extract, hypoxia, and H₂O₂, NEP activity and expression were also reduced. Reactive oxygen species inactivated NEP activity; NEP protein degradation appeared to be substantially induced. CONCLUSIONS Mechanisms responsible for reduced NEP activity and protein expression include oxidative reactions and protein degradation. Maintaining or increasing lung NEP may protect against pulmonary vascular remodeling in response to chronic smoke and hypoxia.
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Affiliation(s)
- Marilee J Wick
- Cardiovascular Pulmonary Research Laboratory, University of Colorado Denver, Aurora, CO 80045, USA.
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19
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Recurrent Pulmonary Capillary Hemangiomatosis After Bilateral Lung Transplantation. J Thorac Imaging 2010; 25:W89-92. [DOI: 10.1097/rti.0b013e3181adebc7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Rajkumar R, Konishi K, Richards TJ, Ishizawar DC, Wiechert AC, Kaminski N, Ahmad F. Genomewide RNA expression profiling in lung identifies distinct signatures in idiopathic pulmonary arterial hypertension and secondary pulmonary hypertension. Am J Physiol Heart Circ Physiol 2010; 298:H1235-48. [PMID: 20081107 DOI: 10.1152/ajpheart.00254.2009] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Idiopathic pulmonary arterial hypertension (PAH) is a life-threatening condition characterized by pulmonary arteriolar remodeling. This investigation aimed to identify genes involved specifically in the pathogenesis of PAH and not other forms of pulmonary hypertension (PH). Using genomewide microarray analysis, we generated the largest data set to date of RNA expression profiles from lung tissue specimens from 1) 18 PAH subjects and 2) 8 subjects with PH secondary to idiopathic pulmonary fibrosis (IPF) and 3) 13 normal subjects. A molecular signature of 4,734 genes discriminated among these three cohorts. We identified significant novel biological changes that were likely to contribute to the pathogenesis of PAH, including regulation of actin-based motility, protein ubiquitination, and cAMP, transforming growth factor-beta, MAPK, estrogen receptor, nitric oxide, and PDGF signaling. Bone morphogenic protein receptor type II expression was downregulated, even in subjects without a mutation in this gene. Women with PAH had higher expression levels of estrogen receptor 1 than normal women. Real-time quantitative PCR confirmed differential expression of the following genes in PAH relative to both normal controls and PH secondary to IPF: a disintegrin-like and metalloprotease with thrombospondin type 1 motif 9, cell adhesion molecule with homology to L1CAM, cytochrome b(558) and beta-polypeptide, coagulation factor II receptor-like 3, A-myb myeloblastosis viral oncogene homolog 1, nuclear receptor coactivator 2, purinergic receptor P2Y, platelet factor 4, phospholamban, and tropomodulin 3. This study shows that PAH and PH secondary to IPF are characterized by distinct gene expression signatures, implying distinct pathophysiological mechanisms.
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Affiliation(s)
- Revathi Rajkumar
- Cardiovascular Institute, Univ. of Pittsburgh, PA 15213-2582, USA
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21
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Rodriguez-Murillo L, Subaran R, Stewart WCL, Pramanik S, Marathe S, Barst RJ, Chung WK, Greenberg DA. Novel loci interacting epistatically with bone morphogenetic protein receptor 2 cause familial pulmonary arterial hypertension. J Heart Lung Transplant 2009; 29:174-80. [PMID: 19864167 DOI: 10.1016/j.healun.2009.08.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 08/25/2009] [Accepted: 08/25/2009] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Familial pulmonary arterial hypertension (FPAH) is a rare, autosomal-dominant, inherited disease with low penetrance. Mutations in the bone morphogenetic protein receptor 2 (BMPR2) have been identified in at least 70% of FPAH patients. However, the lifetime penetrance of these BMPR2 mutations is 10% to 20%, suggesting that genetic and/or environmental modifiers are required for disease expression. Our goal in this study was to identify genetic loci that may influence FPAH expression in BMPR2 mutation carriers. METHODS We performed a genome-wide linkage scan in 15 FPAH families segregating for BMPR2 mutations. We used a dense single-nucleotide polymorphism (SNP) array and a novel multi-scan linkage procedure that provides increased power and precision for the localization of linked loci. RESULTS We observed linkage evidence in four regions: 3q22 ([median log of the odds (LOD) = 3.43]), 3p12 (median LOD) = 2.35), 2p22 (median LOD = 2.21), and 13q21 (median LOD = 2.09). When used in conjunction with the non-parametric bootstrap, our approach yields high-resolution to identify candidate gene regions containing putative BMPR2-interacting genes. Imputation of the disease model by LOD-score maximization indicates that the 3q22 locus alone predicts most FPAH cases in BMPR2 mutation carriers, providing strong evidence that BMPR2 and the 3q22 locus interact epistatically. CONCLUSIONS Our findings suggest that genotypes at loci in the newly identified regions, especially at 3q22, could improve FPAH risk prediction in FPAH families. We also suggest other targets for therapeutic intervention.
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Affiliation(s)
- Laura Rodriguez-Murillo
- Division of Statistical Genetics, Department of Biostatistics, Columbia University Medical Center, New York, New York, USA
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22
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Austin ED, Phillips JA, Cogan JD, Hamid R, Yu C, Stanton KC, Phillips CA, Wheeler LA, Robbins IM, Newman JH, Loyd JE. Truncating and missense BMPR2 mutations differentially affect the severity of heritable pulmonary arterial hypertension. Respir Res 2009; 10:87. [PMID: 19785764 PMCID: PMC2762975 DOI: 10.1186/1465-9921-10-87] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 09/28/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Autosomal dominant inheritance of germline mutations in the bone morphogenetic protein receptor type 2 (BMPR2) gene are a major risk factor for pulmonary arterial hypertension (PAH). While previous studies demonstrated a difference in severity between BMPR2 mutation carriers and noncarriers, it is likely disease severity is not equal among BMPR2 mutations. We hypothesized that patients with missense BMPR2 mutations have more severe disease than those with truncating mutations. METHODS Testing for BMPR2 mutations was performed in 169 patients with PAH (125 with a family history of PAH and 44 with sporadic disease). Of the 106 patients with a detectable BMPR2 mutation, lymphocytes were available in 96 to functionally assess the nonsense-mediated decay pathway of RNA surveillance. Phenotypic characteristics were compared between BMPR2 mutation carriers and noncarriers, as well as between those carriers with a missense versus truncating mutation. RESULTS While there was a statistically significant difference in age at diagnosis between carriers and noncarriers, subgroup analysis revealed this to be the case only for females. Among carriers, there was no difference in age at diagnosis, death, or survival according to exonic location of the BMPR2 mutation. However, patients with missense mutations had statistically significant younger ages at diagnosis and death, as well as shorter survival from diagnosis to death or lung transplantation than those with truncating mutations. Consistent with this data, the majority of missense mutations were penetrant prior to age 36 years, while the majority of truncating mutations were penetrant after age 36 years. CONCLUSION In this cohort, BMPR2 mutation carriers have more severe PAH disease than noncarriers, but this is only the case for females. Among carriers, patients with missense mutations that escape nonsense-mediated decay have more severe disease than those with truncating mutations. These findings suggest that treatment and prevention strategies directed specifically at BMPR2 pathway defects may need to vary according to the type of mutation.
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Affiliation(s)
- Eric D Austin
- Department of Pediatrics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - John A Phillips
- Department of Pediatrics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Joy D Cogan
- Department of Pediatrics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Rizwan Hamid
- Department of Pediatrics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Chang Yu
- Department of Biostatistics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Krista C Stanton
- Department of Pediatrics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Charles A Phillips
- Department of Pediatrics, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Lisa A Wheeler
- Department of Medicine, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - Ivan M Robbins
- Department of Medicine, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - John H Newman
- Department of Medicine, Vanderbilt University, Medical Center, Nashville, TN, USA
| | - James E Loyd
- Department of Medicine, Vanderbilt University, Medical Center, Nashville, TN, USA
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Cyclooxygenase-2 inhibition and hypoxia-induced pulmonary hypertension: effects on pulmonary vascular remodeling and contractility. Trends Cardiovasc Med 2009; 19:31-7. [PMID: 19577709 DOI: 10.1016/j.tcm.2009.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a significant disease process characterized by elevated pulmonary vascular resistance leading to increased right ventricular afterload and ultimately progressing to right ventricular dysfunction and often death. Irreversible remodeling of the pulmonary vasculature is the hallmark of pulmonary hypertension and frequently leads to progressive functional decline in patients with PAH despite treatment with currently available therapies. Metabolites of the arachidonic acid cascade play an important homeostatic role in the pulmonary vasculature, and dysregulation of pathways downstream of arachidonic acid plays a central role in the pathobiology of PAH. Cyclooxygenase-2 (COX-2) is up-regulated in pulmonary artery smooth muscle cells (PASMC) and inflammatory cells during hypoxia and plays a protective role in the lung's response to hypoxia. We recently demonstrated that absence of COX-2 was detrimental in a mouse model of hypoxia-induced pulmonary hypertension. Exposure of COX-2 null mice to hypoxia resulted in severe pulmonary hypertension characterized by enhanced pulmonary vascular remodeling and significant up-regulation of the endothelin-1 receptor ET(A)R in the lung after hypoxia. Absence of COX-2 in vitro led to enhanced contractility of PASMC after exposure to hypoxia, which could be attenuated by iloprost, a prostaglandin I(2) analog. These findings suggest that selective inhibition of COX-2 may have detrimental pulmonary vascular consequences in patients with preexisting pulmonary hypertension or underlying hypoxemic lung diseases. Here, we discuss our recent data demonstrating the adverse consequences of COX-2 inhibition on pulmonary vascular remodeling and PASMC contractility.
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Austin ED, Loyd JE, Phillips JA. Genetics of pulmonary arterial hypertension. Semin Respir Crit Care Med 2009; 30:386-98. [PMID: 19634078 DOI: 10.1055/s-0029-1233308] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Tremendous progress has been made in understanding the genetics of hereditable pulmonary arterial hypertension (HPAH) since its description in the 1950s. Germline mutations in the gene coding bone morphogenetic receptor type 2 ( BMPR2) are detectable in the majority of cases of HPAH, and in a small proportion of cases of idiopathic pulmonary arterial hypertension (IPAH). HPAH is an autosomal dominant disease characterized by reduced penetrance, variable expressivity, female predominance, and genetic anticipation. These characteristics suggest that endogenous and exogenous factors modify disease expression and areas of emphasis for future investigation. The variable clinical expression makes genetic counseling complex because the majority of carriers of a BMPR2 mutation will not be diagnosed with the disease. This issue will become increasingly important, as clinical testing for BMPR2 mutations is now available for the evaluation of patients and family members with HPAH and IPAH.
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Affiliation(s)
- Eric D Austin
- Department of Pediatrics, Division of Pulmonary, Allergy, and Immunology Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2578, USA
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25
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Nisbet RE, Bland JM, Kleinhenz DJ, Mitchell PO, Walp ER, Sutliff RL, Hart CM. Rosiglitazone attenuates chronic hypoxia-induced pulmonary hypertension in a mouse model. Am J Respir Cell Mol Biol 2009; 42:482-90. [PMID: 19520921 DOI: 10.1165/rcmb.2008-0132oc] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Chronic hypoxia contributes to pulmonary hypertension through complex mechanisms that include enhanced NADPH oxidase expression and reactive oxygen species (ROS) generation in the lung. Stimulation of peroxisome proliferator-activated receptor gamma (PPARgamma) reduces the expression and activity of NADPH oxidase. Therefore, we hypothesized that activating PPARgamma with rosiglitazone would attenuate chronic hypoxia-induced pulmonary hypertension, in part, through suppressing NADPH oxidase-derived ROS that stimulate proliferative signaling pathways. Male C57Bl/6 mice were exposed to chronic hypoxia (CH, Fi(O2) 10%) or room air for 3 or 5 weeks. During the last 10 days of exposure, each animal was treated daily by gavage with either the PPARgamma ligand, rosiglitazone (10 mg/kg/d) or with an equal volume of vehicle. CH increased: (1) right ventricular systolic pressure (RVSP), (2) right ventricle weight, (3) thickness of the walls of small pulmonary vessels, (4) superoxide production and Nox4 expression in the lung, and (5) platelet-derived growth factor receptor beta (PDGFRbeta) expression and activity and reduced phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression. Treatment with rosiglitazone prevented the development of pulmonary hypertension at 3 weeks; reversed established pulmonary hypertension at 5 weeks; and attenuated CH-stimulated Nox4 expression and superoxide production, PDGFRbeta activation, and reductions in PTEN expression. Rosiglitazone also attenuated hypoxia-induced increases in Nox4 expression in pulmonary endothelial cells in vitro despite hypoxia-induced reductions in PPARgamma expression. Collectively, these findings indicate that PPARgamma ligands attenuated hypoxia-induced pulmonary vascular remodeling and hypertension by suppressing oxidative and proliferative signals providing novel insights for mechanisms underlying therapeutic effects of PPARgamma activation in pulmonary hypertension.
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Affiliation(s)
- Rachel E Nisbet
- Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia 30033, USA
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26
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Dempsey EC, Wick MJ, Karoor V, Barr EJ, Tallman DW, Wehling CA, Walchak SJ, Laudi S, Le M, Oka M, Majka S, Cool CD, Fagan KA, Klemm DJ, Hersh LB, Gerard NP, Gerard C, Miller YE. Neprilysin null mice develop exaggerated pulmonary vascular remodeling in response to chronic hypoxia. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:782-96. [PMID: 19234135 DOI: 10.2353/ajpath.2009.080345] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neprilysin is a transmembrane metalloendopeptidase that degrades neuropeptides that are important for both growth and contraction. In addition to promoting carcinogenesis, decreased levels of neprilysin increases inflammation and neuroendocrine cell hyperplasia, which may predispose to vascular remodeling. Early pharmacological studies showed a decrease in chronic hypoxic pulmonary hypertension with neprilysin inhibition. We used a genetic approach to test the alternate hypothesis that neprilysin depletion increases chronic hypoxic pulmonary hypertension. Loss of neprilysin had no effect on baseline airway or alveolar wall architecture, vessel density, cardiac function, hematocrit, or other relevant peptidases. Only lung neuroendocrine cell hyperplasia and a subtle neuropeptide imbalance were found. After chronic hypoxia, neprilysin-null mice exhibited exaggerated pulmonary hypertension and striking increases in muscularization of distal vessels. Subtle thickening of proximal media/adventitia not typically seen in mice was also detected. In contrast, adaptive right ventricular hypertrophy was less than anticipated. Hypoxic wild-type pulmonary vessels displayed close temporal and spatial relationships between decreased neprilysin and increased cell growth. Smooth muscle cells from neprilysin-null pulmonary arteries had increased proliferation compared with controls, which was decreased by neprilysin replacement. These data suggest that neprilysin may be protective against chronic hypoxic pulmonary hypertension in the lung, at least in part by attenuating the growth of smooth muscle cells. Lung-targeted strategies to increase neprilysin levels could have therapeutic benefits in the treatment of this disorder.
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Affiliation(s)
- Edward C Dempsey
- Cardiovascular Pulmonary Research Laboratory; B-133, University of Colorado Denver, 12700 E. 19 Ave, Aurora, CO 80046, USA.
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27
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Rolland PH, de Lagausie P, Stathopoulos E, Leprètre O, Viudes G, Gorincour G, Hery G, de Magnée C, Paut O, Guys JM. Phasic hemodynamics and reverse blood flows in the aortic isthmus and pulmonary arteries of preterm lambs with pulmonary vascular dysfunction. Am J Physiol Heart Circ Physiol 2008; 295:H2231-41. [PMID: 18820030 DOI: 10.1152/ajpheart.00410.2008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Time-domain representations of the fetal aortopulmonary circulation were carried out in lamb fetuses to study hemodynamic consequences of congenital diaphragmatic hernia (CDH) and the effects of endothelin-receptor antagonist tezosentan (3 mg/45 min). From the isthmic aortic and left pulmonary artery (PA) flows (Q) and isthmic aortic, PA, and left auricle pressures (P) on day 135 in 10 controls and 7 CDH fetuses (28 ewes), discrete-triggered P and Q waveforms were modelized as Pt and Qt functions to obtain basic hemodynamic profiles, pulsatile waves [P, Q, and entry impedance (Ze)], and P and Q hysteresis loops. In the controls, blood propelling energy was accounted for by biventricular ejection flow waves (kinetic energy) with low Ze and by flow-driven pressure waves (potential energy) with low Ze. Weak fetal pulmonary perfusion was ensured by reflux (reverse flows) from PA branches to the ductus anteriosus and aortic isthmus as reverse flows. Endothelin-receptor antagonist blockade using tezosentan slightly increased the forward flow but largely increased diastolic backward flow with a diminished left auricle pre- and postloading. In CHD fetuses, the static component overrode phasic flows that were detrimental to reverse flows and the direction of the diastolic isthmic flow changed to forward during the diastole period. Decreased cardiac output, flattened pressure waves, and increased forward Ze promoted backward flow to the detriment of forward flow (especially during diastole). Additionally, the intrapulmonary arteriovenous shunting was ineffective. The slowing of cardiac output, the dampening of energetic pressure waves and pulsatility, and the heightening of phasic impedances contributed to the lowering of aortopulmonary blood flows. We speculate that reverse pulmonary flow is a physiological requirement to protect the fetal pulmonary circulation from the prominent right ventricular stream and to enhance blood flow to the fetal heart and brain.
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Affiliation(s)
- Pierre-Henri Rolland
- Physiopathology and Vascular Therapeutics, School of Medicine, University of the Mediterranean Sea, 27 Blvd. Jean-Moulin, and Department of Pediatric Surgery, LaTimone-Hospital, Marseilles, France.
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28
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Tsai HH, Chen IJ, Lo YC. Effects of San-Huang-Xie-Xin-Tang on U46619-induced increase in pulmonary arterial blood pressure. JOURNAL OF ETHNOPHARMACOLOGY 2008; 117:457-62. [PMID: 18387761 DOI: 10.1016/j.jep.2008.02.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 01/09/2008] [Accepted: 02/20/2008] [Indexed: 05/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE San-Huang-Xie-Xin-Tang (SHXT), composed of Coptidis rhizoma, Scutellariae radix and Rhei rhizoma, is traditionally used to treat hypertension. AIM OF THE STUDY Our aim was to investigate the pharmacology effect of SHXT on a thromboxane A(2) analogue U46619-induced increase in pulmonary hypertension and protein expression in primary pulmonary smooth muscle cells (PASMCs). MATERIALS AND METHODS Arterial blood pressure and isometric tension in the aorta and pulmonary artery of rats were measured by pressure and force transducers, respectively. Protein expressions on PASMCs were detected by Western blotting. RESULTS SHXT significantly attenuated U46619-induced increase in arterial blood pressure. The inhibitory effect of SHXT on pulmonary arterial pressure was greater than systemic arterial pressure in U46619 treated rats. Similarly, the inhibitory effect of SHXT on U46619-induced vasoconstriction in rat pulmonary arterial rings was greater than that in aortic rings. In U46619 treated PASMCs, SHXT down-regulated expression of phosphodiesterase type 5 (PDE5), Rho-kinase (ROCK) II, cyclooxygenase-2 (COX-2) and up-regulated expression of soluble guanylyl cyclase (sGC) alpha(1) and sGCbeta(1). CONCLUSIONS SHXT attenuated U46619-induced increase in systemic and pulmonary arterial blood pressure. Inhibition of PDE5, ROCK-II, COX-2 and stimulation of sGC may play important roles in the cardiovascular effects of SHXT.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
- Animals
- Aorta, Thoracic/drug effects
- Blood Pressure/drug effects
- Blotting, Western
- Cell Separation
- Cell Survival/drug effects
- Cyclic Nucleotide Phosphodiesterases, Type 5/biosynthesis
- Cyclooxygenase 2/biosynthesis
- Cyclooxygenase 2/genetics
- Drugs, Chinese Herbal/pharmacology
- In Vitro Techniques
- Isometric Contraction/drug effects
- Male
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Myocytes, Smooth Muscle/drug effects
- Pulmonary Artery/drug effects
- Rats
- Rats, Sprague-Dawley
- Vasoconstrictor Agents
- rho-Associated Kinases/biosynthesis
- rho-Associated Kinases/genetics
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Affiliation(s)
- Hsin-Hung Tsai
- Department of Pharmacology College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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29
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Lafaras C, Mandala E, Verrou E, Platogiannis D, Barbetakis N, Bischiniotis T, Zervas K. Non-thromboembolic pulmonary hypertension in multiple myeloma, after thalidomide treatment: a pilot study. Ann Oncol 2008; 19:1765-9. [PMID: 18480066 DOI: 10.1093/annonc/mdn287] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Multiple myeloma (MM) is thrombogenic as a consequence of multiple hemostatic effects and endothelial damage. Thalidomide has been associated with an increased risk of thromboembolic pulmonary hypertension (PH). PH in the absence of venous thromboembolism has also been described in MM patients during thalidomide treatment. AIM Detection of clinical and subclinical nonthromboembolic PH in MM patients after thalidomide treatment. PATIENTS AND METHODS Eighty-two patients, 46-82 years (median age 61 years), 42 males, were studied. They underwent echocardiographic study at baseline, 1 month thereafter, 6 months later and whenever symptoms indicating deterioration of cardiac function appeared. Echocardiographic signs of PH were especially identified. RESULTS Clinical and echocardiographic evaluation revealed four patients (out of 82 patients, 4.87%) with PH. Nonimaging and imaging diagnostic methods excluded thromboembolic PH. Statistical analysis demonstrated significant correlation between structural heart disease and PH (r = 14.078; P = 0.008). No significant correlation between age (r = 0.770; P = 0.724), gender (r = 1.157; P = 0.285), International Staging System (ISS) (r = 0.316; P = 0.716) and PH was found. CONCLUSIONS Preexisted endothelial dysfunction due to structural cardiac disease enhances the vasoactive substances release causing increased pulmonary vascular resistance. Thalidomide possibly causes a vasodilator and vasoconstriction imbalance, which may cause abnormal pulmonary vascular response interfering to a vicious circle perpetuating PH.
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Affiliation(s)
- C Lafaras
- Department of Cardiology, Theagenion Cancer Hospital, Thessaloniki, Greece.
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30
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O'Callaghan DS. Emerging treatments for pulmonary arterial hypertension. CLINICAL RESPIRATORY JOURNAL 2008; 2:132-40. [DOI: 10.1111/j.1752-699x.2008.00059.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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31
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Rubin LJ. Treatment of Pulmonary Arterial Hypertension Due to Scleroderma: Challenges for the Future. Rheum Dis Clin North Am 2008; 34:191-7; viii. [DOI: 10.1016/j.rdc.2007.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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De Franceschi L, Platt OS, Malpeli G, Janin A, Scarpa A, Leboeuf C, Beuzard Y, Payen E, Brugnara C. Protective effects of phosphodiesterase-4 (PDE-4) inhibition in the early phase of pulmonary arterial hypertension in transgenic sickle cell mice. FASEB J 2008; 22:1849-60. [PMID: 18245171 DOI: 10.1096/fj.07-098921] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pulmonary arterial hypertension (PAH) is one of the leading causes of morbidity and mortality in adult patients with sickle cell disease (SCD). Here, we developed a model to study the early stage of PAH in SCD. We exposed wild-type and transgenic sickle cell SAD (Hbb(s)/Hbb(s)) mice to hypoxia (8% O(2)) for 7 days. Prolonged hypoxia in SAD mice only induced 1) increased neutrophil count in both bronchoalveolar lavage (BAL) and peripheral circulation; 2) increased BAL IL1beta, IL10, IL6, and TNF-alpha; and 3) up-regulation of the genes endothelin-1, cyclo-oxygenase-2, angiotensin-converting-enzyme, and IL-1beta, suggesting that amplified inflammatory response and activation of the endothelin-1 system may contribute to the early phase of PAH in SCD. Since phosphodiesterases (PDEs) are involved in pulmonary vascular tone regulation, we evaluated gene expression of phosphodiesterase-4 (PDE-4) isoforms and of PDE-1, -2, -3, -7, -8, which are the main cyclic-adenosine-monophosphate hydrolyzing enzymes. In SAD mouse lungs, prolonged hypoxia significantly increased PDE-4 and -1 gene expressions. The PDE-4 inhibitor, rolipram, prevented the hypoxia-induced PDE-4 and -1 gene up-regulation and interfered with the development of PAH, most likely through modulation of both vascular tone and inflammatory factors. This finding supports a possible therapeutic use of PDEs inhibitors in the earlier phases of PAH in SCD.
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Affiliation(s)
- Lucia De Franceschi
- Department of Clinical and Experimental Medicine, Section of Internal Medicine, University of Verona, Policlinico GB Rossi, 37134 Verona, Italy.
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33
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Oka M, Homma N, McMurtry IF. Rho kinase-mediated vasoconstriction in rat models of pulmonary hypertension. Methods Enzymol 2008; 439:191-204. [PMID: 18374166 DOI: 10.1016/s0076-6879(07)00415-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
There is current controversy regarding whether vasoconstriction plays a significant role in the elevated pressure of severe, advanced stages of pulmonary hypertension. Results of acute vasodilator testing using conventional vasodilators in such patients suggest there is only a minor contribution of vasoconstriction. However, there is a possibility that these results may underestimate the contribution of vasoconstriction because the most effective vasodilators have not yet been tested. This issue has not been addressed even experimentally, due mainly to a lack of appropriate animal models. A few animal models that mimic the pathology of human severe pulmonary hypertension more closely (i.e., development of occlusive neointimal lesions in small pulmonary arteries/arterioles) have been introduced, including rat models of left lung pneumonectomy plus monocrotaline injection and vascular endothelial growth factor inhibition plus exposure to chronic hypoxia. We have observed that Rho kinase inhibitors, a novel class of potent vasodilators, reduce the high pulmonary artery pressure of these models acutely and markedly, suggesting that vasoconstriction can significantly be involved in pulmonary hypertension with severely remodeled (occluded) pulmonary vessels. This chapter describes methods used for evaluation of the involvement of Rho kinase-mediated vasoconstriction in rat models of pulmonary hypertension.
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Affiliation(s)
- Masahiko Oka
- Cardiovascular Pulmonary Research Laboratory, University of Colorado at Denver, Health Sciences Center, Denver, Colorado, USA
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34
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Pokreisz P, Marsboom G, Janssens S. Pressure overload-induced right ventricular dysfunction and remodelling in experimental pulmonary hypertension: the right heart revisited. Eur Heart J Suppl 2007. [DOI: 10.1093/eurheartj/sum021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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35
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Patel NM, Lederer DJ, Borczuk AC, Kawut SM. Pulmonary hypertension in idiopathic pulmonary fibrosis. Chest 2007; 132:998-1006. [PMID: 17873194 DOI: 10.1378/chest.06-3087] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is an untreatable diffuse parenchymal lung disease with a median survival of < 3 years. Pulmonary hypertension (PH) is frequently seen in patients with IPF and is commonly attributed to hypoxic vasoconstriction and capillary destruction. Pathology findings include endothelial proliferation and medial hypertrophy that exceed those expected in the setting of hypoxia. Noninvasive evaluation has limited sensitivity and specificity for the diagnosis of PH in IPF; therefore, right-heart catheterization remains the "gold standard" diagnostic test. PH in patients with IPF is associated with decreased exercise capacity and worse survival. Given the grave consequences of this condition, treatment of PH could improve functional outcomes and survival. However, possible treatments such as long-term supplemental oxygen and targeted vascular therapy are either unstudied or remain unproven.
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Affiliation(s)
- Nina M Patel
- Department of Medicine, Division of Pulmonary, Allergy & Critical Care, Columbia University, 622 W 168th St, PH 8 East, Room 101, New York, NY 10032, USA.
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36
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Min SK, Kenagy RD, Clowes AW. Induction of vascular atrophy as a novel approach to treating restenosis. A review. J Vasc Surg 2007; 47:662-70. [PMID: 17950562 DOI: 10.1016/j.jvs.2007.07.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 07/24/2007] [Accepted: 07/28/2007] [Indexed: 01/01/2023]
Abstract
Regardless of the type of arterial reconstruction, luminal narrowing (stenosis or restenosis) develops in approximately one third of the vessels. In the past, the focus of research has been on the mechanisms of stenosis (intimal hyperplasia, pathologic remodeling) and pharmacologic approaches to prevention. An alternative approach is to induce intimal atrophy after luminal narrowing has developed, thus limiting treatment to only those patients that develop a problem. This approach to treat established disease by reducing wall mass through induction of cell death and extracellular matrix removal would be particularly useful for treating stenosis in synthetic bypass grafts or stented vessels, in which intimal hyperplasia is the primary mechanism of stenosis. This approach may be applicable as well to other vascular proliferative disorders, such as pulmonary hypertension and chronic transplant arteriopathy. Proof of principle has been shown in experiments with antibodies to platelet-derived growth factor (PDGF) receptors that cause neointimal regression in baboon polytetrafluoroethylene (PTFE) grafts and with angiotensin-converting enzyme inhibitors that induce medial atrophy in hypertensive arteries. Possible molecular targets could include PDGF receptors, A20, and BMP4. Further studies are needed to determine the utility of such a therapeutic approach to vascular disease.
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Affiliation(s)
- Seung-Kee Min
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
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37
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Abstract
Clinically significant pulmonary hypertension (PHTN) is a common finding in newborn infants with congenital diaphragmatic hernia (CDH) resulting in right to left shunting at pre- and postductal level, hypoxemia, and acute right heart failure in those most severely affected. Even in those without clinical manifestations of ductal shunting, cardiac echo studies would suggest that increased pulmonary vascular resistance and right ventricular pressures are almost a universal finding in this disease, and in some instances, may persist well into the postnatal period. The lung is small and structurally abnormal, and the pulmonary vascular bed is not only reduced in size, but responds abnormally to vasodilators. During the last 20 years, "gentle" ventilation, delayed surgery, and improved peri-operative care have made the greatest impact in decreasing mortality in this condition. Use of PGE1 should be considered early if there is hemodynamically significant PHTN, right ventricular dysfunction, and the patent ductus arteriosus (PDA) is becoming restrictive. In individual patients, inhaled nitric oxide (iNO) might be helpful, but the response to iNO should be confirmed using echocardiography. In patients who survive operation and leave the hospital, there are chronic causes of morbidity that need to be looked for and managed in a multi-disciplinary follow-up clinic.
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Affiliation(s)
- Hadi Mohseni-Bod
- Department of Critical Care Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
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38
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Said SI, Hamidi SA, Dickman KG, Szema AM, Lyubsky S, Lin RZ, Jiang YP, Chen JJ, Waschek JA, Kort S. Moderate Pulmonary Arterial Hypertension in Male Mice Lacking the Vasoactive Intestinal Peptide Gene. Circulation 2007; 115:1260-8. [PMID: 17309917 DOI: 10.1161/circulationaha.106.681718] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background—
Vasoactive intestinal peptide (VIP), a pulmonary vasodilator and inhibitor of vascular smooth muscle proliferation, has been reported absent in pulmonary arteries from patients with idiopathic pulmonary arterial hypertension (PAH). We have tested the hypothesis that targeted deletion of the VIP gene may lead to PAH with pulmonary vascular remodeling.
Methods and Results—
We examined VIP knockout (VIP
−/−
) mice for evidence of PAH, right ventricular (RV) hypertrophy, and pulmonary vascular remodeling. Relative to wild-type control mice, VIP
−/−
mice showed moderate RV hypertension, RV hypertrophy confirmed by increased ratio of RV to left ventricle plus septum weight, and enlarged, thickened pulmonary artery and smaller branches with increased muscularization and narrowed lumen. Lung sections also showed perivascular inflammatory cell infiltrates. No systemic hypertension and no arterial hypoxemia existed to explain the PAH. The condition was associated with increased mortality. Both the vascular remodeling and RV remodeling were attenuated after a 4-week treatment with VIP.
Conclusions—
Deletion of the VIP gene leads to spontaneous expression of moderately severe PAH in mice during air breathing. Although not an exact model of idiopathic PAH, the VIP
−/−
mouse should be useful for studying molecular mechanisms of PAH and evaluating potential therapeutic agents. VIP replacement therapy holds promise for the treatment of PAH, and mutations of the VIP gene may be a factor in the pathogenesis of idiopathic PAH.
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Affiliation(s)
- Sami I Said
- Departments of Medicine, State University of New York at Stony Brook, Stony Brook, NY, USA.
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Abstract
Pulmonary arterial hypertension (PAH) is an uncommon disorder of the pulmonary vasculature characterized by remodeling of the smallest pulmonary arteries, leading to a progressive increase in pulmonary vascular resistance. Various forms of PAH exist, including familial (FPAH) and idiopathic (IPAH) forms and associated conditions. FPAH transmits as an autosomal dominant trait that exhibits genetic anticipation but also markedly reduced penetrance (20%). The primary genetic defect of FPAH, identifiable in more than 70% of cases of FPAH, is a mutation in the gene encoding bone morphogenetic protein receptor type 2 (BMPR2), a member of the transforming growth factor beta superfamily. The true prevalence of BMPR2 mutations in IPAH is unknown, with reports ranging from 10% to 40% of patients. The cause of the variable phenotypic expression of PAH among carriers of mutated BMPR2 genes and patients is unclear, and likely related to environmental and genetic modifiers of disease not yet fully elucidated. Although BMPR2-related pathways seem to be pivotal, many other mediator pathways participate in the pathogenesis of different forms of PAH and are being actively investigated, both independently and in combination. As understanding of the molecular basis of this devastating disease improves, opportunities for earlier diagnosis, additional therapeutic regimens, and perhaps disease prevention will emerge.
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Affiliation(s)
- Eric D Austin
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, Vanderbilt University Medical Center, T-1217 Medical Center North, Nashville, TN 37232-2650, USA.
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Merkus D, Houweling B, de Beer VJ, Everon Z, Duncker DJ. Alterations in endothelial control of the pulmonary circulation in exercising swine with secondary pulmonary hypertension after myocardial infarction. J Physiol 2007; 580:907-23. [PMID: 17289783 PMCID: PMC2075461 DOI: 10.1113/jphysiol.2006.127118] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Secondary pulmonary hypertension after myocardial infarction (MI) has been associated with endothelial dysfunction and activation of the endothelin (ET) system. Here, we investigated whether an increased ET-mediated pulmonary vasoconstrictor influence contributes to pulmonary hypertension after MI, and whether this increased ET vasoconstriction is caused by impaired nitric oxide (NO) and prostanoid production. For this purpose, chronically instrumented swine with and without MI ran on a treadmill at 0-4 km h(-1). Mixed ET(A)/ET(B) receptor blockade (tezosentan) was performed in the absence and presence of single or combined inhibition of endothelial NO synthase (eNOS, with N(omega)-nitro-l-arginine) and cyclo-oxygenase (COX, with indometacin). In normal swine, mixed ET(A)/ET(B) blockade decreased pulmonary vascular resistance, but only during exercise. In MI swine, an increased ET-mediated vasoconstrictor influence was observed in the pulmonary circulation both at rest and during exercise. Inhibition of COX resulted in pulmonary vasoconstriction at rest in MI, but not in normal swine; this vasoconstriction in MI swine was normalized by ET(A)/ET(B) receptor blockade. Inhibition of eNOS enhanced the vasodilator response to ET(A)/ET(B) blockade, indicating that NO blunts the pulmonary vasoconstrictor influence of ET. However, this vasodilator response was enhanced to a similar degree in MI and normal swine. In summary, swine with a recent MI are characterized by an exaggerated pulmonary vasoconstrictor influence of ET. This increased ET-mediated pulmonary vasoconstrictor influence is not caused by a loss of NO bioavailability, and is blunted by an increased prostanoid-mediated vasodilatation. In conclusion, an increased ET-mediated vasoconstriction, which does not appear to be the result of loss of endothelial vasodilators, contributes to pulmonary hypertension after MI.
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Affiliation(s)
- Daphne Merkus
- Experimental Cardiology, Thoraxcentre, Cardiovascular Research School COEUR, Erasmus MC, University Medical Centre Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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Abstract
Familial pulmonary arterial hypertension (FPAH) was first described more than 50 years ago. Before the availability of modern genetic tools, studies of the genealogies demonstrated that these cases segregated as an autosomic dominant trait, with an incomplete penetrance and a genetic anticipation phenomenon by which age at onset of the disease is decreasing in the subsequent generations. Germline mutations in the gene coding for the bone morphogenetic protein receptor II (BMPR2) are present in more than 70% of FPAH and up to 26% of idiopathic, apparently sporadic cases (IPAH). Incomplete penetrance (around 20%) is a major pitfall because FPAH becomes ignored when the disease skips one or several generations. Genetic counseling is complex, with a significant number of BMPR2 mutation healthy carriers screened in some families. Incomplete penetrance puts them in the anxious situation of being potentially affected in the future by this devastating condition or to transmit this risk to their offspring. Nevertheless, genetic testing and counseling is about to become a standard in the management of PAH. Recent international guidelines on PAH state that genetic testing is recommended in FPAH and that IPAH patients have to be informed about the availability of such testing.
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Affiliation(s)
- Benjamin Sztrymf
- UPRES EA2705, INSERM U764, IFR13, Service de Pneumologie et Réanimation Respiratoire, Centre National de Référence de l'Hypertension Artérielle Pulmonaire, Hôpital Antoine-Béclère, Université Paris-Sud, Clamart, France.
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