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Katz MG, Hadas Y, Shtraizent N, Ravvin S, Madjarov JM, Eliyahu E. Unilateral Lung Removal in Combination with Monocrotaline or SU5416 in Rodents: A Reliable Model to Mimic the Pathology of the Human Pulmonary Hypertension. Methods Mol Biol 2024; 2803:173-185. [PMID: 38676893 DOI: 10.1007/978-1-0716-3846-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2024]
Abstract
Pulmonary hypertension (PH) is a chronic and progressive disorder characterized by elevated mean pulmonary arterial pressure, pulmonary vascular remodeling, and the development of concentric laminar intimal fibrosis with plexiform lesions. While rodent models have been developed to study PH, they have certain deficiencies and do not entirely replicate the human disease due to the heterogeneity of PH pathology. Therefore, combined models are necessary to study PH. Recent studies have shown that altered pulmonary blood flow is a significant trigger in the development of vascular remodeling and neointimal lesions. One of the most promising rodent models for increased pulmonary flow is the combination of unilateral left pneumonectomy with a "second hit" of monocrotaline (MCT) or SU5416. The removal of one lung in this model forces blood to circulate only in the other lung and induces increased and turbulent pulmonary blood flow. This increased vascular flow leads to progressive remodeling and occlusion of small pulmonary arteries. The second hit by MCT or SU5416 leads to endothelial cell dysfunction, resulting in severe PH and the development of plexiform arteriopathy.
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Affiliation(s)
- Michael G Katz
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Cardiovascular Surgery and Pediatric Cardiac Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Yoav Hadas
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Shana Ravvin
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jeko M Madjarov
- Atrium Health Sanger Heart and Vascular Institute, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Efrat Eliyahu
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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古 丽, 刘 才, 谢 亮, 顾 玲, 余 莉, 刘 瀚. [Pulmonary Vascular Remodeling Characteristics of Pulmonary Arterial Hypertension Mouse Model Induced by Left Pneumonectomy and Jugular Vein Injection of Monocrotaline Pyrrole]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2022; 53:821-827. [PMID: 36224684 PMCID: PMC10408802 DOI: 10.12182/20220960508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Indexed: 06/16/2023]
Abstract
Objective To compare and investigate the differences and characteristics of pulmonary vascular remodeling in three mouse models of pulmonary arterial hypertension (PAH) constructed by left pneumonectomy, jugular vein injection of monocrotaline pyrrole, and left pneumonectomy combined with jugular vein injection of monocrotaline pyrrole, to explore for a PAH animal model that approximates the clinical pathogenesis of PAH, and to create a model that will provide sound basis for thorough investigation into the pathogenesis of severe PAH. Methods 59 male C57/BL mice (10-12 weeks, 24-30 g) were randomized into four groups, a control group ( n=9), a group that had left pneumonectomy (PE, n=15), a group that had jugular vein injection of monocrotaline pyrrole (MCTP, n=15), and the last group that had left pneumonectomy combined with jugular injection of monocrotaline pyrrole (P+M, n=20). To evaluate the effect of modeling and the characteristics of pulmonary vascular remodeling, hemodynamic and morphological parameters, including right ventricular systolic pressure (RVSP), right ventricle/(left ventricle plus septum) (RV/LV+S), percent of wall thickness in the pulmonary artery (WT%), muscularization of non-muscular arteries, neointima formation, and vascular obstruction score (VOS), were measured in each group. Results 1) Compared with those of the control group, the RVSP, RV/LV+S, WT%, and the degree of small pulmonary arteries muscularization in the P+M group were significantly increased ( P<0.01). The MCTP group had just slightly higher findings for these indicators ( P<0.05), while no significant change in these indicators was observed in the PE group ( P>0.05). 2) Neointima formation in the acinus pulmonary arteries, which caused obvious stenosis of the lumen, was observed in the P+M group, the VOS being 1.25±0.80 points ( P<0.001). In contrast, neointima formation was not observed in the MCTP group or the PE groups, the VOS being 0 point ( P>0.05). Conclusion Left pneumonectomy combined with jugular intravenous injection of MCTP could induce severe PAH formation in mouse. The model provides a good simulation of neointima formation, the characteristic pathological change of clinical severe PAH.
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Affiliation(s)
- 丽 古
- 出生缺陷与相关妇儿疾病教育部重点实验室(四川大学) (成都 610041)Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 宜宾市第一人民医院 儿科 (宜宾 644000)Department of Pediatrics, the First People's Hospital of Yibin, Yibin 644000, China
| | - 才俊 刘
- 出生缺陷与相关妇儿疾病教育部重点实验室(四川大学) (成都 610041)Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 宜宾市第一人民医院 儿科 (宜宾 644000)Department of Pediatrics, the First People's Hospital of Yibin, Yibin 644000, China
| | - 亮 谢
- 出生缺陷与相关妇儿疾病教育部重点实验室(四川大学) (成都 610041)Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 宜宾市第一人民医院 儿科 (宜宾 644000)Department of Pediatrics, the First People's Hospital of Yibin, Yibin 644000, China
| | - 玲 顾
- 出生缺陷与相关妇儿疾病教育部重点实验室(四川大学) (成都 610041)Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 宜宾市第一人民医院 儿科 (宜宾 644000)Department of Pediatrics, the First People's Hospital of Yibin, Yibin 644000, China
| | - 莉 余
- 出生缺陷与相关妇儿疾病教育部重点实验室(四川大学) (成都 610041)Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 宜宾市第一人民医院 儿科 (宜宾 644000)Department of Pediatrics, the First People's Hospital of Yibin, Yibin 644000, China
| | - 瀚旻 刘
- 出生缺陷与相关妇儿疾病教育部重点实验室(四川大学) (成都 610041)Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 宜宾市第一人民医院 儿科 (宜宾 644000)Department of Pediatrics, the First People's Hospital of Yibin, Yibin 644000, China
- 四川大学华西第二医院 小儿呼吸免疫科 (成都 610041)Department of Pediatric Pulmonology and Immunology, West China Second University Hospital, Sichuan University, Chengdu 610041, China
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Cober ND, VandenBroek MM, Ormiston ML, Stewart DJ. Evolving Concepts in Endothelial Pathobiology of Pulmonary Arterial Hypertension. Hypertension 2022; 79:1580-1590. [PMID: 35582968 DOI: 10.1161/hypertensionaha.122.18261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a deadly disease, characterized by increased vascular resistance, pulmonary arteriolar loss, and occlusive arterial remodeling, leading to eventual right heart failure. Evidence increasingly points to the pulmonary endothelium as a central actor in PAH. Endothelial cell apoptosis can result directly in distal lung arteriolar pruning and indirectly in the formation of complex and occlusive arterial lesions, reflecting an imbalance between endothelial injury and repair in the development and progression of PAH. Many of the mutations implicated in PAH are in genes, which are predominantly, or solely, expressed in endothelial cells, and the endothelium is a major target for therapeutic interventions to restore BMP signaling. We explore how arterial pruning can promote the emergence of occlusive arterial remodeling mediated by ongoing endothelial injury secondary to hemodynamic perturbation and pathological increases in luminal shear stress. The emerging role of endothelial cell senescence is discussed in the transition from reversible to irreversible arterial remodeling in advanced PAH, and we review the sometimes conflicting evidence that female sex hormones can both protect or promote vascular changes in disease. Finally, we explore the contribution of the endothelium to metabolic changes and the altered inflammatory and immune state in the PAH lung, focusing on the role of excessive TGFβ signaling. Given the complexity of the endothelial pathobiology of PAH, we anticipate that emerging technologies that allow the study of molecular events at a single cell level will provide answers to many of the questions raised in this review.
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Affiliation(s)
- Nicholas D Cober
- Ottawa Hospital Research Institute, ON, Canada (N.D.C., D.J.S.).,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, ON, Canada (N.D.C., D.J.S.)
| | - M Martin VandenBroek
- Department of Medicine, Queen's University, Kingston, ON, Canada (M.M.V., M.L.O.)
| | - Mark L Ormiston
- Department of Medicine, Queen's University, Kingston, ON, Canada (M.M.V., M.L.O.).,Departments of Surgery, and Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada (M.L.O.)
| | - Duncan J Stewart
- Ottawa Hospital Research Institute, ON, Canada (N.D.C., D.J.S.).,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, ON, Canada (N.D.C., D.J.S.)
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Dong ML, Lan IS, Yang W, Rabinovitch M, Feinstein JA, Marsden AL. Computational simulation-derived hemodynamic and biomechanical properties of the pulmonary arterial tree early in the course of ventricular septal defects. Biomech Model Mechanobiol 2021; 20:2471-2489. [PMID: 34585299 DOI: 10.1007/s10237-021-01519-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 09/12/2021] [Indexed: 01/15/2023]
Abstract
Untreated ventricular septal defects (VSDs) can lead to pulmonary arterial hypertension (PAH) characterized by elevated pulmonary artery (PA) pressure and vascular remodeling, known as PAH associated with congenital heart disease (PAH-CHD). Though previous studies have investigated hemodynamic effects on vascular mechanobiology in late-stage PAH, hemodynamics leading to PAH-CHD initiation have not been fully quantified. We hypothesize that abnormal hemodynamics from left-to-right shunting in early stage VSDs affects PA biomechanical properties leading to PAH initiation. To model PA hemodynamics in healthy, small, moderate, and large VSD conditions prior to the onset of vascular remodeling, computational fluid dynamics simulations were performed using a 3D finite element model of a healthy 1-year-old's proximal PAs and a body-surface-area-scaled 0D distal PA tree. VSD conditions were modeled with increased pulmonary blood flow to represent degrees of left-to-right shunting. In the proximal PAs, pressure, flow, strain, and wall shear stress (WSS) increased with increasing VSD size; oscillatory shear index decreased with increasing VSD size in the larger PA vessels. WSS was higher in smaller diameter vessels and increased with VSD size, with the large VSD condition exhibiting WSS >100 dyn/cm[Formula: see text], well above values typically used to study dysfunctional mechanotransduction pathways in PAH. This study is the first to estimate hemodynamic and biomechanical metrics in the entire pediatric PA tree with VSD severity at the stage leading to PAH initiation and has implications for future studies assessing effects of abnormal mechanical stimuli on endothelial cells and vascular wall mechanics that occur during PAH-CHD initiation and progression.
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Affiliation(s)
- Melody L Dong
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Ingrid S Lan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Weiguang Yang
- Department of Pediatrics, Stanford University, Stanford, CA, USA
| | | | - Jeffrey A Feinstein
- Department of Pediatrics and Bioengineering, Stanford University, Stanford, CA, USA
| | - Alison L Marsden
- Department of Pediatrics and Bioengineering, Stanford University, Stanford, CA, USA.
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Andersen A, van der Feen DE, Andersen S, Schultz JG, Hansmann G, Bogaard HJ. Animal models of right heart failure. Cardiovasc Diagn Ther 2020; 10:1561-1579. [PMID: 33224774 PMCID: PMC7666958 DOI: 10.21037/cdt-20-400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/13/2020] [Indexed: 12/17/2022]
Abstract
Right heart failure may be the ultimate cause of death in patients with acute or chronic pulmonary hypertension (PH). As PH is often secondary to other cardiovascular diseases, the treatment goal is to target the underlying disease. We do however know, that right heart failure is an independent risk factor, and therefore, treatments that improve right heart function may improve morbidity and mortality in patients with PH. There are no therapies that directly target and support the failing right heart and translation from therapies that improve left heart failure have been unsuccessful, with the exception of mineralocorticoid receptor antagonists. To understand the underlying pathophysiology of right heart failure and to aid in the development of new treatments we need solid animal models that mimic the pathophysiology of human disease. There are several available animal models of acute and chronic PH. They range from flow induced to pressure overload induced right heart failure and have been introduced in both small and large animals. When initiating new pre-clinical or basic research studies it is key to choose the right animal model to ensure successful translation to the clinical setting. Selecting the right animal model for the right study is hence important, but may be difficult due to the plethora of different models and local availability. In this review we provide an overview of the available animal models of acute and chronic right heart failure and discuss the strengths and limitations of the different models.
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Affiliation(s)
- Asger Andersen
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
| | - Diederik E. van der Feen
- Center for Congenital Heart Diseases, University Medical Center Groningen, Groningen, The Netherlands
| | - Stine Andersen
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Georg Hansmann
- Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany
| | - Harm Jan Bogaard
- Amsterdam UMC, Vrije Universiteit Amsterdam, Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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6
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Remodeling Matrix Synthesis in a Rat Model of Aortocaval Fistula and the Cyclic Stretch: Impaction in Pulmonary Arterial Hypertension-Congenital Heart Disease. Int J Mol Sci 2020; 21:ijms21134676. [PMID: 32630068 PMCID: PMC7370183 DOI: 10.3390/ijms21134676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/28/2020] [Accepted: 06/28/2020] [Indexed: 01/22/2023] Open
Abstract
Pulmonary arterial hypertension-congenital heart disease (PAH-CHD) is characterized by systemic to pulmonary arterial shunts and sensitively responds to volume overload and stretch of the vascular wall leading to pulmonary vascular remodeling. We hypothesized that the responses of pulmonary artery smooth muscle cells (PASMCs) to mechanical stress-associated volume overload may promote vascular remodeling in PAH-CHD. Here, we show that significantly increased collagen was in the PA adventitial layer by trichrome staining in PAH-CHD patients and an aortocaval fistula (ACF) rat model in which chronic vascular volume overload induced-PAH. We assessed the gene expression profiles of SMC markers, extracellular matrix, and collagen in isolated SMCs from pulmonary and thoracic vessels with cyclic stretch-triggered responses by real-time PCR analysis. The data corresponded to collagen deposition, which modulated pulmonary vascular remodeling in clinical and experimental PAH-ACF cases as well as in cyclic stretch-triggered SMCs in an in vitro model. We observe that collagen I A2 (COLIA2) is expressed in the control rat, but collagen I A1 (COLIA1) and Notchs remarkably increase in the lungs of ACF rats. Interestingly, closing the left-to-right shunt that leads to a reduced blood volume in the PA system of ACF rats (ACFRs) decreased the expression of COLIA1 and increased that of collagen I A2(COLIA2). This study contributes to the stretch-induced responses of SMCs and provides important future directions for therapies aimed at preventing abnormal matrix protein synthesis in volume overload-induced pulmonary hypertension (PH).
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Katz MG, Fargnoli AS, Gubara SM, Bisserier M, Sassi Y, Bridges CR, Hajjar RJ, Hadri L. The Left Pneumonectomy Combined with Monocrotaline or Sugen as a Model of Pulmonary Hypertension in Rats. J Vis Exp 2019. [PMID: 30907889 DOI: 10.3791/59050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In this protocol, we detail the correct procedural steps and necessary precautions to successfully perform a left pneumonectomy and induce PAH in rats with the additional administration of monocrotaline (MCT) or SU5416 (Sugen). We also compare these two models to other PAH models commonly used in research. In the last few years, the focus of animal PAH models has moved towards studying the mechanism of angioproliferation of plexiform lesions, in which the role of increased pulmonary blood flow is considered as an important trigger in the development of severe pulmonary vascular remodeling. One of the most promising rodent models of increased pulmonary flow is the unilateral left pneumonectomy combined with a "second hit" of MCT or Sugen. The removal of the left lung leads to increased and turbulent pulmonary blood flow and vascular remodeling. Currently, there is no detailed procedure of the pneumonectomy surgery in rats. This article details a step-by-step protocol of the pneumonectomy surgical procedure and post-operative care in male Sprague-Dawley rats. Briefly, the animal is anesthetized and the chest is opened. Once the left pulmonary artery, pulmonary vein, and bronchus are visualized, they are ligated and the left lung is removed. The chest then closed and the animal recovered. Blood is forced to circulate only on the right lung. This increased vascular pressure leads to a progressive remodeling and occlusion of small pulmonary arteries. The second hit of MCT or Sugen is used one week post-surgery to induce endothelial dysfunction. The combination of increased blood flow in the lung and endothelial dysfunction produces severe PAH. The primary limitation of this procedure is that it requires general surgical skills.
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Affiliation(s)
- Michael G Katz
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Anthony S Fargnoli
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Sarah M Gubara
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Malik Bisserier
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Yassine Sassi
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Charles R Bridges
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Roger J Hajjar
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Lahouaria Hadri
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai;
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Fukumitsu M, Kawada T, Shimizu S, Turner MJ, Uemura K, Sugimachi M. Wave reflection correlates with pulmonary vascular wall thickening in rats with pulmonary arterial hypertension. Int J Cardiol 2017; 249:396-401. [DOI: 10.1016/j.ijcard.2017.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 07/20/2017] [Accepted: 09/08/2017] [Indexed: 10/18/2022]
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Abstract
The circulation of the lung is unique both in volume and function. For example, it is the only organ with two circulations: the pulmonary circulation, the main function of which is gas exchange, and the bronchial circulation, a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries and veins. The pulmonary circulation accommodates the entire cardiac output, maintaining high blood flow at low intravascular arterial pressure. As compared with the systemic circulation, pulmonary arteries have thinner walls with much less vascular smooth muscle and a relative lack of basal tone. Factors controlling pulmonary blood flow include vascular structure, gravity, mechanical effects of breathing, and the influence of neural and humoral factors. Pulmonary vascular tone is also altered by hypoxia, which causes pulmonary vasoconstriction. If the hypoxic stimulus persists for a prolonged period, contraction is accompanied by remodeling of the vasculature, resulting in pulmonary hypertension. In addition, genetic and environmental factors can also confer susceptibility to development of pulmonary hypertension. Under normal conditions, the endothelium forms a tight barrier, actively regulating interstitial fluid homeostasis. Infection and inflammation compromise normal barrier homeostasis, resulting in increased permeability and edema formation. This article focuses on reviewing the basics of the lung circulation (pulmonary and bronchial), normal development and transition at birth and vasoregulation. Mechanisms contributing to pathological conditions in the pulmonary circulation, in particular when barrier function is disrupted and during development of pulmonary hypertension, will also be discussed.
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Affiliation(s)
- Karthik Suresh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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Pugliese SC, Poth JM, Fini MA, Olschewski A, El Kasmi KC, Stenmark KR. The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes. Am J Physiol Lung Cell Mol Physiol 2014; 308:L229-52. [PMID: 25416383 DOI: 10.1152/ajplung.00238.2014] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop "out-of-proportion" severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines ("second hit") antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.
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Affiliation(s)
- Steven C Pugliese
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado;
| | - Jens M Poth
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Mehdi A Fini
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; and
| | - Karim C El Kasmi
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of Colorado Denver, School of Medicine, Anschutz Medical Campus, Aurora, Colorado
| | - Kurt R Stenmark
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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12
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Wang Y, Xue XY, Liu YX, Wang KF, Zang XF, Wang J, Wang PL, Zhang J, Pan L, Zhang SY, Wang JX. Pulmonary Arterial Hypertension and MicroRNAs—An Ever-growing Partnership. Arch Med Res 2013; 44:483-7. [DOI: 10.1016/j.arcmed.2013.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 08/14/2013] [Indexed: 01/02/2023]
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Tanaka Y, Takase B, Yao T, Ishihara M. Right Ventricular Electrical Remodeling and Arrhythmogenic Substrate in Rat Pulmonary Hypertension. Am J Respir Cell Mol Biol 2013; 49:426-36. [DOI: 10.1165/rcmb.2012-0089oc] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Dickinson MG, Bartelds B, Borgdorff MAJ, Berger RMF. The role of disturbed blood flow in the development of pulmonary arterial hypertension: lessons from preclinical animal models. Am J Physiol Lung Cell Mol Physiol 2013; 305:L1-14. [PMID: 23624788 DOI: 10.1152/ajplung.00031.2013] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a progressive pulmonary vasoproliferative disorder characterized by the development of unique neointimal lesions, including concentric laminar intima fibrosis and plexiform lesions. Although the histomorphology of neointimal lesions is well described, the pathogenesis of PAH and neointimal development is largely unknown. After three decades of PAH pathobiology research the focus has shifted from vasoconstriction towards a mechanism of cancer-like angioproliferation. In this concept the role of disturbed blood flow is seen as an important trigger in the development of vascular remodeling. For instance, in PAH associated with congenital heart disease, increased pulmonary blood flow (i.e., systemic-to-pulmonary shunt) is an essential trigger for the occurrence of neointimal lesions and PAH development. Still, questions remain about the exact role of these blood flow characteristics in disease progression. PAH animal models are important for obtaining insight in new pathobiological processes and therapeutical targets. However, as for any preclinical model the pathophysiological mechanism and clinical course has to be comparable to the human disease that it mimics. This means that animal models mimicking human PAH ideally are characterized by: a hit recognized in human disease (e.g., altered pulmonary blood flow), specific vascular remodeling resembling human neointimal lesions, and disease progression that leads to right ventriclular dysfunction and death. A review that underlines the current knowledge of PAH due to disturbed flow is still lacking. In this review we will summarize the current knowledge obtained from PAH animal models associated with disturbed pulmonary blood flow and address questions for future treatment strategies for PAH.
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Affiliation(s)
- Michael G Dickinson
- Center for Congenital Heart Diseases, Division of Pediatric Cardiology Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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Vascular remodeling in pulmonary hypertension. J Mol Med (Berl) 2013; 91:297-309. [PMID: 23334338 DOI: 10.1007/s00109-013-0998-0] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/04/2013] [Accepted: 01/08/2013] [Indexed: 02/07/2023]
Abstract
Pulmonary hypertension is a complex, progressive condition arising from a variety of genetic and pathogenic causes. Patients present with a spectrum of histologic and pathophysiological features, likely reflecting the diversity in underlying pathogenesis. It is widely recognized that structural alterations in the vascular wall contribute to all forms of pulmonary hypertension. Features characteristic of the remodeled vasculature in patients with pulmonary hypertension include increased stiffening of the elastic proximal pulmonary arteries, thickening of the intimal and/or medial layer of muscular arteries, development of vaso-occlusive lesions, and the appearance of cells expressing smooth muscle-specific markers in normally non-muscular small diameter vessels, resulting from proliferation and migration of pulmonary arterial smooth muscle cells and cellular transdifferentiation. The development of several animal models of pulmonary hypertension has provided the means to explore the mechanistic underpinnings of pulmonary vascular remodeling, although none of the experimental models currently used entirely replicates the pulmonary arterial hypertension observed in patients. Herein, we provide an overview of the histological abnormalities observed in humans with pulmonary hypertension and in preclinical models and discuss insights gained regarding several key signaling pathways contributing to the remodeling process. In particular, we will focus on the roles of ion homeostasis, endothelin-1, serotonin, bone morphogenetic proteins, Rho kinase, and hypoxia-inducible factor 1 in pulmonary arterial smooth muscle and endothelial cells, highlighting areas of cross-talk between these pathways and potentials for therapeutic targeting.
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16
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George MP, Champion HC, Simon M, Guyach S, Tarantelli R, Kling HM, Brower A, Janssen C, Murphy J, Carney JP, Morris A, Gladwin MT, Norris KA. Physiologic changes in a nonhuman primate model of HIV-associated pulmonary arterial hypertension. Am J Respir Cell Mol Biol 2012; 48:374-81. [PMID: 23239493 DOI: 10.1165/rcmb.2011-0434oc] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is increased in HIV, but its pathogenesis is not fully understood. Nonhuman primates infected with simian immunodeficiency virus (SIV) or SIV-HIV chimeric virus (SHIV) exhibit histologic changes characteristic of human PAH, but whether hemodynamic changes accompany this pathology is unknown. Repeated measurements of pulmonary artery pressures would permit longitudinal assessments of disease development and provide insights into pathogenesis. We tested the hypothesis that SIV-infected and SHIV-infected macaques develop physiologic manifestations of PAH. We performed right heart catheterizations, echocardiography, and computed tomography (CT) scans in macaques infected with either SIV (ΔB670) or SHIV (89.6P), and compared right heart and pulmonary artery pressures, as well as pulmonary vascular changes on CT scans, with those in uninfected control animals. Right atrial, right ventricular systolic, and pulmonary artery pressures (PAPs) were significantly elevated in 100% of macaques infected with either SIV or SHIV compared with control animals, with no difference in pulmonary capillary wedge pressure. PAPs increased as early as 3 months after SIV infection. Radiographic evidence of pulmonary vascular pruning was also found. Both SIV-infected and SHIV-infected macaques exhibited histologic changes in pulmonary arteries, predominantly consisting of intimal and medial hyperplasia. This report is the first to demonstrate SHIV-infected and SIV-infected macaques develop pulmonary hypertension at a high frequency, with physiologic changes occurring as early as 3 months after infection. These studies establish an important nonhuman primate model of HIV-associated PAH that will be useful in studies of disease pathogenesis and the efficacy of interventions.
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Affiliation(s)
- M Patricia George
- Department of Immunology, School of Medicine, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15261.
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Polonio IB, Acencio MMP, Pazetti R, Almeida FMD, Canzian M, Silva BSD, Pereira KAB, Souza RD. Comparação de dois modelos experimentais de hipertensão pulmonar. J Bras Pneumol 2012; 38:452-60. [DOI: 10.1590/s1806-37132012000400007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 05/10/2012] [Indexed: 11/22/2022] Open
Abstract
OBJETIVO: Comparar dois modelos de hipertensão pulmonar (monocrotalina e monocrotalina+pneumonectomia) em relação à gravidade hemodinâmica, estrutura de artérias pulmonares, marcadores inflamatórios (IL-1 e PDGF) e sobrevida em 45 dias. MÉTODOS: Foram utilizados 80 ratos Sprague-Dawley em dois protocolos de estudo: análise estrutural e de sobrevida. Os animais foram divididos em quatro grupos: controle, monocrotalina (M), pneumonectomia (P) e monocrotalina+pneumonectomia (M+P). Para a análise estrutural, 40 animais (10/grupo) foram cateterizados após 28 dias para a medição dos valores hemodinâmicos e sacrificados, obtendo-se tecidos cardíaco e pulmonar. O ventrículo direito (VD) foi dissecado do septo interventricular (SI), e a relação do peso do VD e do peso do ventrículo esquerdo (VE) com o SI foi obtida como índice de hipertrofia de VD. No tecido pulmonar, foram realizadas análises histológicas e dosados IL-1 e PDGF por ELISA. Para o estudo de sobrevida, 40 animais (10/grupo) foram observados por 45 dias. RESULTADOS: Os grupos M e M+P apresentaram hipertensão pulmonar em relação aos demais. Houve um aumento significativo da relação VD/VE+S no grupo M+P em relação aos demais. Não houve diferenças significativas entre os grupos M e M+P quanto à área da camada média das artérias pulmonares, dosagens de IL-1 e PDGF ou sobrevida. CONCLUSÕES: Baseados nos resultados, não podemos afirmar que o modelo de monocrotalina+pneumonectomia é superior ao modelo de monocrotalina.
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Affiliation(s)
- Igor Bastos Polonio
- Universidade de São Paulo; Irmandade da Santa Casa de Misericórdia de São Paulo, Brasil
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Dorfmüller P, Chaumais MC, Giannakouli M, Durand-Gasselin I, Raymond N, Fadel E, Mercier O, Charlotte F, Montani D, Simonneau G, Humbert M, Perros F. Increased oxidative stress and severe arterial remodeling induced by permanent high-flow challenge in experimental pulmonary hypertension. Respir Res 2011; 12:119. [PMID: 21906276 PMCID: PMC3189121 DOI: 10.1186/1465-9921-12-119] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 09/09/2011] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Involvement of inflammation in pulmonary hypertension (PH) has previously been demonstrated and recently, immune-modulating dendritic cells (DCs) infiltrating arterial lesions in patients suffering from idiopathic pulmonary arterial hypertension (IPAH) and in experimental monocrotaline-induced PH have been reported. Occurrence of perivascular inflammatory cells could be linked to local increase of oxidative stress (OS), as it has been shown for systemic atherosclerosis. The impact of OS on vascular remodeling in PH is still to be determined. We hypothesized, that augmented blood-flow could increase OS and might thereby contribute to DC/inflammatory cell-recruitment and smooth-muscle-cell-proliferation. METHODS We applied a monocrotaline-induced PH-model and combined it with permanent flow-challenge. Thirty Sprague-Dawley rats were assigned to following groups: control, monocrotaline-exposure (MCT), monocrotaline-exposure/pneumonectomy (MCT/PE). RESULTS Hemodynamic exploration demonstrated most severe effects in MCT/PE, corresponding in histology to exuberant medial and adventitial remodeling of pulmonary muscular arteries, and intimal remodeling of smaller arterioles; lung-tissue PCR evidenced increased expression of DCs-specific fascin, CD68, proinflammatory cytokines (IL-6, RANTES, fractalkine) in MCT/PE and to a lesser extent in MCT. Major OS enzyme NOX-4 was maximal in MCT/PE. Antioxidative stress enzymes Mn-SOD and glutathion-peroxidase-1 were significantly elevated, while HO-1 showed maximal expression in MCT with significant decrease in MCT/PE. Catalase was decreased in MCT and MCT/PE. Expression of NOX-4, but also of MN-SOD in MCT/PE was mainly attributed to a highly increased number of interstitial and perivascular CXCR4/SDF1 pathway-recruited mast-cells. Stress markers malonedialdehyde and nitrotyrosine were produced in endothelial cells, medial smooth muscle and perivascular leucocytes of hypertensive vasculature. Immunolabeling for OX62, CD68 and actin revealed adventitial and medial DC- and monocyte-infiltration; in MCT/PE, medial smooth muscle cells were admixed with CD68+/vimentin+ cells. CONCLUSION Our experimental findings support a new concept of immunologic responses to increased OS in MCT/PE-induced PAH, possibly linking recruitment of dendritic cells and OS-producing mast-cells to characteristic vasculopathy.
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Affiliation(s)
- Peter Dorfmüller
- Université Paris-Sud, Faculté de médecine, Kremlin-Bicêtre, F-94276, France.
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Wideman RF, Hamal KR, Bayona MT, Lorenzoni AG, Cross D, Khajali F, Rhoads DD, Erf GF, Anthony NB. Plexiform lesions in the lungs of domestic fowl selected for susceptibility to pulmonary arterial hypertension: incidence and histology. Anat Rec (Hoboken) 2011; 294:739-55. [PMID: 21448992 DOI: 10.1002/ar.21369] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 01/07/2010] [Accepted: 01/31/2010] [Indexed: 11/11/2022]
Abstract
Plexiform lesions develop in the pulmonary arteries of humans suffering from idiopathic pulmonary arterial hypertension (IPAH). Plexogenic arteriopathy rarely develops in existing animal models of IPAH. In this study, plexiform lesions developed in the lungs of rapidly growing meat-type chickens (broiler chickens) that had been genetically selected for susceptibility to IPAH. Plexiform lesions developed spontaneously in: 42% of females and 40% of males; 35% of right lungs, and 45% of left lungs; and, at 8, 12, 16, 20, 24, and 52 weeks of age the plexiform lesion incidences averaged 52%, 50%, 51%, 40%, 36%, and 22%, respectively. Plexiform lesions formed distal to branch points in muscular interparabronchial pulmonary arteries exhibiting intimal proliferation. Perivascular mononuclear cell infiltrates consistently surrounded the affected arteries. Proliferating intimal cells fully or partially occluded the arterial lumen adjacent to plexiform lesions. Broilers reared in clean stainless steel cages exhibited a 50% lesion incidence that did not differ from the 64% incidence in flock mates grown on dusty floor litter. Microparticles (30 μm diameter) were injected to determine if physical occlusion and focal inflammation within distal pulmonary arteries might initiate plexiform lesion development. Three months postinjection no plexiform lesions were observed in the vicinity of persisting microparticles. Broiler chickens selected for innate susceptibility to IPAH represent a new animal model for investigating the mechanisms responsible for spontaneous plexogenic arteriopathy.
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Affiliation(s)
- Robert F Wideman
- Department of Poultry Science, University of Arkansas, Fayetteville, USA.
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20
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Wideman RF, Hamal KR. Idiopathic pulmonary arterial hypertension: an avian model for plexogenic arteriopathy and serotonergic vasoconstriction. J Pharmacol Toxicol Methods 2011; 63:283-95. [PMID: 21277983 DOI: 10.1016/j.vascn.2011.01.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/15/2010] [Accepted: 01/18/2011] [Indexed: 01/15/2023]
Abstract
Idiopathic pulmonary arterial hypertension (IPAH) is a disease of unknown cause that is characterized by elevated pulmonary arterial pressure and pulmonary vascular resistance attributable to vasoconstriction and vascular remodeling of small pulmonary arteries. Vascular remodeling includes hypertrophy and hyperplasia of smooth muscle (medial hypertrophy) accompanied in up to 80% of the cases by the formation of occlusive plexiform lesions (plexogenic arteriopathy). Patients tend to be unresponsive to vasodilator therapy and have a poor prognosis for survival when plexogenic arteriopathy progressively obstructs their pulmonary arteries. Research is needed to understand and treat plexogenic arteriopathy, but advances have been hindered by the absence of spontaneously developing lesions in existing laboratory animal models. Young domestic fowl bred for meat production (broiler chickens, broilers) spontaneously develop IPAH accompanied by semi-occlusive endothelial proliferation that progresses into fully developed plexiform lesions. Plexiform lesions develop in both female and male broilers, and lesion incidences (lung sections with lesions/lung sections examined) averaged approximately 40% in 8 to 52 week old birds. Plexiform lesions formed distal to branch points in muscular interparabronchial pulmonary arteries, and were associated with perivascular mononuclear cell infiltrates. Serotonin (5-hydroxytryptamine, 5-HT) is a potent vasoconstrictor and mitogen known to stimulate vascular endothelial and smooth muscle cell proliferation. Serotonin has been directly linked to the pathogenesis of IPAH in humans, including IPAH linked to serotonergic anorexigens that trigger the formation of plexiform lesions indistinguishable from those observed in primary IPAH triggered by other causes. Serotonin also plays a major role in the susceptibility of broilers to IPAH. This avian model of spontaneous IPAH constitutes a new animal model for biomedical research focused on the pathogenesis of IPAH and plexogenic arteriopathy.
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Affiliation(s)
- Robert F Wideman
- Center of Excellence for Poultry Science, Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
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Chan SY, Loscalzo J. Pulmonary vascular disease related to hemodynamic stress in the pulmonary circulation. Compr Physiol 2011; 1:123-39. [PMID: 23737167 PMCID: PMC3730284 DOI: 10.1002/cphy.c090004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hemodynamic stress in the pulmonary vessel is directly linked to the development of vascular remodeling and dysfunction, ultimately leading to pulmonary hypertension. Recently, some advances have been made in our molecular understanding of the exogenous upstream stimuli that initiate hemodynamic pertubations as well as the downstream vasoactive effectors that control these responses. However, much still remains unknown regarding how these complex signaling pathways connect in order to result in these characteristic pathophysiological changes. This chapter will describe our current understanding of and needed areas of research into the clinical, physiological, and molecular changes associated with pressure/volume overload in the pulmonary circulation.
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Affiliation(s)
- Stephen Y. Chan
- Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Joseph Loscalzo
- Division of Cardiovascular Medicine Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
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Stenmark KR, Meyrick B, Galie N, Mooi WJ, McMurtry IF. Animal models of pulmonary arterial hypertension: the hope for etiological discovery and pharmacological cure. Am J Physiol Lung Cell Mol Physiol 2009; 297:L1013-32. [DOI: 10.1152/ajplung.00217.2009] [Citation(s) in RCA: 565] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
At present, six groups of chronic pulmonary hypertension (PH) are described. Among these, group 1 (and 1′) comprises a group of diverse diseases termed pulmonary arterial hypertension (PAH) that have several pathophysiological, histological, and prognostic features in common. PAH is a particularly severe and progressive form of PH that frequently leads to right heart failure and premature death. The diagnosis of PAH must include a series of defined clinical parameters, which extend beyond mere elevations in pulmonary arterial pressures and include precapillary PH, pulmonary hypertensive arteriopathy (usually with plexiform lesions), slow clinical onset (months or years), and a chronic time course (years) characterized by progressive deterioration. What appears to distinguish PAH from other forms of PH is the severity of the arteriopathy observed, the defining characteristic of which is “plexogenic arteriopathy.” The pathogenesis of this arteriopathy remains unclear despite intense investigation in a variety of animal model systems. The most commonly used animal models (“classic” models) are rodents exposed to either hypoxia or monocrotaline. Newer models, which involve modification of classic approaches, have been developed that exhibit more severe PH and vascular lesions, which include neointimal proliferation and occlusion of small vessels. In addition, genetically manipulated mice have been generated that have provided insight into the role of specific molecules in the pulmonary hypertensive process. Unfortunately, at present, there is no perfect preclinical model that completely recapitulates human PAH. All models, however, have provided and will continue to provide invaluable insight into the numerous pathways that contribute to the development and maintenance of PH. Use of both classic and newly developed animal models will allow continued rigorous testing of new hypotheses regarding pathogenesis and treatment. This review highlights progress that has been made in animal modeling of this important human condition.
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Transforming Growth Factor β/Bone Morphogenic Protein Signaling in Pulmonary Arterial Hypertension: Remodeling Revisited. Trends Cardiovasc Med 2007; 17:263-9. [DOI: 10.1016/j.tcm.2007.09.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 09/06/2007] [Accepted: 09/10/2007] [Indexed: 11/24/2022]
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Ito T, Okada T, Miyashita H, Nomoto T, Nonaka-Sarukawa M, Uchibori R, Maeda Y, Urabe M, Mizukami H, Kume A, Takahashi M, Ikeda U, Shimada K, Ozawa K. Interleukin-10 expression mediated by an adeno-associated virus vector prevents monocrotaline-induced pulmonary arterial hypertension in rats. Circ Res 2007; 101:734-41. [PMID: 17673672 DOI: 10.1161/circresaha.107.153023] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a fatal disease associated with inflammation and pathological remodeling of the pulmonary artery (PA). Interleukin (IL)-10 is a pleiotropic antiinflammatory cytokine with vasculoprotective properties. Here, we report the preventive effects of IL-10 on monocrotaline-induced PAH. Three-week-old Wistar rats were intramuscularly injected with an adeno-associated virus serotype 1 vector expressing IL-10, followed by monocrotaline injection at 7 weeks old. IL-10 transduction significantly improved survival rates of the PAH rats 8 weeks after monocrotaline administration compared with control gene transduction (75% versus 0%, P<0.01). IL-10 also significantly reduced mean PA pressure (22.8+/-1.5 versus 29.7+/-2.8 mm Hg, P<0.05), a weight ratio of right ventricle to left ventricle plus septum (0.35+/-0.04 versus 0.42+/-0.05, P<0.05), and percent medial thickness of the PA (12.9+/-0.3% versus 21.4+/-0.4%, P<0.01) compared with controls. IL-10 significantly reduced macrophage infiltration and vascular cell proliferation in the remodeled PA in vivo. It also significantly decreased the lung levels of transforming growth factor-beta1 and IL-6, which are indicative of PA remodeling. In addition, IL-10 increased the lung level of heme oxygenase-1, which strongly prevents PA remodeling. In vitro analysis revealed that IL-10 significantly inhibited excessive proliferation of cultured human PA smooth muscle cells treated with transforming growth factor-beta1 or the heme oxygenase inhibitor tin protoporphyrin IX. Thus, IL-10 prevented the development of monocrotaline-induced PAH, and these results provide new insights into the molecular mechanisms of human PAH.
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Affiliation(s)
- Takayuki Ito
- Division of Genetic Therapeutics, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
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Ramos M, Lamé MW, Segall HJ, Wilson DW. Monocrotaline pyrrole induces Smad nuclear accumulation and altered signaling expression in human pulmonary arterial endothelial cells. Vascul Pharmacol 2007; 46:439-48. [PMID: 17336165 PMCID: PMC2570208 DOI: 10.1016/j.vph.2007.01.005] [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: 07/06/2006] [Revised: 01/03/2007] [Accepted: 01/22/2007] [Indexed: 12/31/2022]
Abstract
The mechanistic relationship between the widely used monocrotaline model of primary pulmonary hypertension and altered TGFbeta family signaling due to genetic defects in the Bone Morphogenetic Protein type II receptor in affected humans has not been investigated. In this study we use fluorescent microscopy to demonstrate nuclear translocation of Smad 4 in human pulmonary arterial endothelial cell (HPAEC) cultures treated with monocrotaline pyrrole (MCTP), Bone Morphogenetic Protein (BMP) and TGFbeta. While MCTP induced transient nuclear accumulation of phosphorylated Smad 1 (P-Smad 1) and phosphorylated Smad 2 (P-Smad 2), only expression of P-Smad 1 was significantly altered in western blots. P-Smad 1 expression significantly increased 30 min following treatment with MCTP correlating with P-Smad 1 and Smad 4 nuclear translocation. Although a modest, but significant decrease in P-Smad 1 expression occurred 1 h after treatment, expression was significantly increased at 72 h. Evaluation of components of the signal and response pathway at 72 h showed decreased expression of the BMP type II receptor (BMPrII), no change in TGFbeta Activin Receptor-like Kinase 1 (Alk 1), no change in Smad 4 but increase in the inhibitory Smad 6, decrease in the alternate BMP signaling pathway p38(MAPK) but no change in the psmad1 response element ID 1. Our results suggest transient activation of Smad signaling pathways in initial MCTP endothelial cell toxicity, and a persistent dysregulation of BMP signaling. Electron microscopy of cell membrane caveoli revealed a dramatic decrease in these structures after 72 h. Loss of these structural elements, noted for their sequestration and inhibition of receptor activity, may contribute to prolonged alterations in BMP signaling.
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Affiliation(s)
- M Ramos
- Department of Veterinary Medicine, Pathology, Immunology, Microbiology, University of California, Davis, Davis, California 95616, USA
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Abstract
The secondary role of pathology in the present clinical management of pulmonary hypertension (PH) reflects to some extent the limitations of the current understanding of the disease. Ample room exists for the diagnostic translation of the pathobiologic studies, with the goal of improving the diagnostic and prognostic power of the pathologic assessment of pulmonary vascular remodeling. This article seeks to show the complementarities of the pathology and pathobiology of PH.
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Affiliation(s)
- Rubin M Tuder
- Division of Cardiopulmonary Pathology, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Research Building, Baltimore, MD 21217, USA.
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van Albada ME, van Veghel R, Cromme-Dijkhuis AH, Schoemaker RG, Berger RMF. Treprostinil in advanced experimental pulmonary hypertension: beneficial outcome without reversed pulmonary vascular remodeling. J Cardiovasc Pharmacol 2007; 48:249-54. [PMID: 17110807 DOI: 10.1097/01.fjc.0000248229.87510.9b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Beneficial effects of treprostinil, a stable prostacyclin analogue, were demonstrated in patients with pulmonary arterial hypertension (PAH). Although regression of pulmonary vascular remodeling has been suggested as therapeutic mechanism, its mode of action remains unknown. METHODS Flow-associated PAH was created in rats by injection of monocrotaline (60 mg/kg) combined with an abdominal aortocaval shunt. Subsequently, rats were treated with subcutaneous treprostinil (50 ng/kg/min, treated; n = 8) or saline (untreated; n = 9). A control group underwent sham-surgery (n = 8). Animals were sacrificed at symptoms of cardiac failure, together with their matched controls. RESULTS Dyspnea and weight loss determined the moment of sacrifice in 8/9 untreated animals (89%) versus in one of eight treated animals (13%; log-rank test survival curves; P = 0.02). Mean pulmonary arterial pressure increased in the model (42 +/- 2 mm Hg in untreated vs. 18 +/- 1 in controls; P < 0.01) and decreased by 8 mm Hg after therapy (34 +/- 3 mm Hg, P = 0.04 vs. untreated). No effects of treatment on right ventricular hypertrophy could be demonstrated. Quantitative morphometry of pre- and intra-acinar pulmonary arteries revealed no effects of treatment on vessel histopathology. CONCLUSIONS Treprostinil treatment improved clinical course and ameliorated symptoms of heart failure in a model of advanced PAH. However, beneficial effects were not associated with reversed structural remodelling of the pulmonary vasculature.
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Affiliation(s)
- Mirjam E van Albada
- Department of Pediatrics, Division of Pediatric Cardiology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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Abstract
Chronic thromboembolic pulmonary hypertension is a condition that is recognised in an increased percentage of patients. Pulmonary endarterectomy is recognised as being the only curative option for a subgroup of those patients, but anaesthesiologists and intensivists face many challenges in how they manage these patients perioperatively. Ultimately, it is the combination of skills in a multidisciplinary team that leads to a successful procedure and dramatically improves patient's quality of life and life expectancy.
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Ivy DD, McMurtry IF, Colvin K, Imamura M, Oka M, Lee DS, Gebb S, Jones PL. Development of occlusive neointimal lesions in distal pulmonary arteries of endothelin B receptor-deficient rats: a new model of severe pulmonary arterial hypertension. Circulation 2005; 111:2988-96. [PMID: 15927975 PMCID: PMC1934986 DOI: 10.1161/circulationaha.104.491456] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Human pulmonary arterial hypertension (PAH) is characterized by proliferation of vascular smooth muscle and, in its more severe form, by the development of occlusive neointimal lesions. However, few animal models of pulmonary neointimal proliferation exist, thereby limiting a complete understanding of the pathobiology of PAH. Recent studies of the endothelin (ET) system demonstrate that deficiency of the ET(B) receptor predisposes adult rats to acute and chronic hypoxic PAH, yet these animals fail to develop neointimal lesions. Herein, we determined and thereafter showed that exposure of ET(B) receptor-deficient rats to the endothelial toxin monocrotaline (MCT) leads to the development of neointimal lesions that share hallmarks of human PAH. METHODS AND RESULTS The pulmonary hemodynamic and morphometric effects of 60 mg/kg MCT in control (MCT(+/+)) and ET(B) receptor-deficient (MCT(sl/sl)) rats at 6 weeks of age were assessed. MCT(sl/sl) rats developed more severe PAH, characterized by elevated pulmonary artery pressure, diminished cardiac output, and right ventricular hypertrophy. In MCT(sl/sl) rats, morphometric evaluation revealed the presence of neointimal lesions within small distal pulmonary arteries, increased medial wall thickness, and decreased arterial-to-alveolar ratio. In keeping with this, barium angiography revealed diminished distal pulmonary vasculature of MCT(sl/sl) rat lungs. Cells within neointimal lesions expressed smooth muscle and endothelial cell markers. Moreover, cells within neointimal lesions exhibited increased levels of proliferation and were located in a tissue microenvironment enriched with vascular endothelial growth factor, tenascin-C, and activated matrix metalloproteinase-9, factors already implicated in human PAH. Finally, assessment of steady state mRNA showed that whereas expression of ET(B) receptors was decreased in MCT(sl/sl) rat lungs, ET(A) receptor expression increased. CONCLUSIONS Deficiency of the ET(B) receptor markedly accelerates the progression of PAH in rats treated with MCT and enhances the appearance of cellular and molecular markers associated with the pathobiology of PAH. Collectively, these results suggest an overall antiproliferative effect of the ET(B) receptor in pulmonary vascular homeostasis.
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Affiliation(s)
- D Dunbar Ivy
- Section of Pediatric Cardiology, University of Colorado School of Medicine and Children's Hospital, Denver 80218, USA.
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Bernardo WM, Jatene FB, Demarchi LMMF, Capelozzi VL, Pazetti R, Rivero DHRF, Monteiro R, Oliveira SAD. Análise da remodelação vascular na isquemia pulmonar experimental, nas fases aguda e crônica. J Bras Pneumol 2005. [DOI: 10.1590/s1806-37132005000100006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUÇÃO: Alterações estruturais da circulação pulmonar traduzem processo de remodelação vascular e têm relação provável com variações locais de fluxo e isquemia. OBJETIVO: Definir as alterações histológicas na circulação pulmonar após obstrução experimental da artéria pulmonar. Correlacioná-las com os padrões de redistribuição sangüínea e remodelação vascular. MÉTODO: Foram submetidos à toracotomia esquerda 48 ratos Wistar, alocados aleatoriamente em dois grupos, com ligadura da artéria pulmonar e controle, e sacrificados com 1, 7, 30 e 60 dias. Nos pulmões retirados avaliou-se presença de sinais de injúria no parênquima e mensurou-se diâmetro externo e espessura da parede das arteríolas de bronquíolos terminais, respiratórios e alveolares. Diâmetro interno e porcentagem de espessura da parede foram calculados. RESULTADOS: Só ocorreu infarto, necrose e hemorragia no pulmão isquêmico. No não isquêmico houve aumento mantido dos diâmetros externo e interno das arteríolas, com redução inicial da espessura no 1º dia e valores semelhantes aos do grupo controle no 60º dia. No pulmão isquêmico houve redução transitória nos diâmetros externo e interno das arteríolas de bronquíolos terminais e respiratórios, com aumento, inicial e transitório, na sua espessura. As arteríolas alveolares apresentaram aumento do diâmetro externo e espessura da parede, com redução do diâmetro interno, mantida e progressiva. CONCLUSÃO: Este modelo reproduz arteriopatia distal em pacientes com tromboembolismo pulmonar crônico. A resposta vascular no pulmão não isquêmico é compatível com padrão de remodelação de hiperfluxo; a no pulmão isquêmico com hipofluxo e isquemia. Nas arteríolas de bronquíolos terminais e respiratórios a resposta foi transitória. Nas alveolares foi progressiva e mantida, pela provável ocorrência tardia de hiperfluxo local.
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Lalezari S, Hazekamp MG, Bartelings MM, Schoof PH, Gittenberger-De Groot AC. Pulmonary artery remodeling in transposition of the great arteries: relevance for neoaortic root dilatation. J Thorac Cardiovasc Surg 2003; 126:1053-60. [PMID: 14566246 DOI: 10.1016/s0022-5223(03)00971-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Transposition of the great arteries is currently treated by performing the arterial switch operation. Dilatation of the neoaortic root is a late complication with unknown cause. Samples of patients with untreated transposition of the great arteries and patients with normally related great arteries were compared to investigate a possible role for vascular remodeling in the dilatation process. METHODS Aortic and pulmonary artery vessel wall and sinus samples were taken from 20 untreated human heart specimens with transposition of the great arteries and 9 age-matched, normal, postmortem human heart specimens, divided into 2 groups according to age. Routine histology and immunohistochemical staining for smooth muscle cell differentiation markers alpha-smooth muscle actin, SM22, and calponin were performed. RESULTS This study revealed structural differences between the normal aorta and pulmonary artery in the early group, which became more pronounced in the late group. In the early stage in transposition of the great arteries, no marked differences were seen between the aorta and pulmonary artery. With increasing age, however, there was a pronounced down-regulation of all smooth muscle cell markers in the pulmonary artery. CONCLUSIONS There is a structural difference between the normal neonatal aorta and pulmonary artery. The great arteries in transposition of the great arteries differ from each other and from normal vessels, indicating a structural vascular difference in transposition of the great arteries. In the pulmonary artery and sinus of untreated transposition of the great arteries, there is a dedifferentiation of smooth muscle cells with increasing age that we could not correlate to altered flow. This structural abnormality might provide an explanation for the neoaortic root dilatation that has been reported as a late complication of the arterial switch operation.
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Affiliation(s)
- Shirin Lalezari
- Department of Anatomy and Embryology, Leiden University Medical Center,, Leiden, The Netherlands
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Qiu D, Kao PN. Immunosuppressive and anti-inflammatory mechanisms of triptolide, the principal active diterpenoid from the Chinese medicinal herb Tripterygium wilfordii Hook. f. Drugs R D 2003; 4:1-18. [PMID: 12568630 DOI: 10.2165/00126839-200304010-00001] [Citation(s) in RCA: 234] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Extracts of Tripterygium wilfordii hook. f. (leigong teng, Thundergod vine) are effective in traditional Chinese medicine for treatment of immune inflammatory diseases including rheumatoid arthritis, systemic lupus erythematosus, nephritis and asthma. Characterisation of the terpenoids present in extracts of Tripterygium identified triptolide, a diterpenoid triepoxide, as responsible for most of the immunosuppressive, anti-inflammatory and antiproliferative effects observed in vitro. Triptolide inhibits lymphocyte activation and T-cell expression of interleukin-2 at the level of transcription. In all cell types examined, triptolide inhibits nuclear factor-kappaB transcriptional activation at a unique step in the nucleus after binding to DNA. Further characterisation of the molecular mechanisms of triptolide action will serve to elucidate pathways of immune system regulation.
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Affiliation(s)
- Daoming Qiu
- Division of Pulmonary and Critical Care Medicine, Stanford University Medical Center, Stanford, California 94305, USA.
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Nishimura T, Faul JL, Berry GJ, Kao PN, Pearl RG. Effect of a surgical aortocaval fistula on monocrotaline-induced pulmonary hypertension. Crit Care Med 2003; 31:1213-8. [PMID: 12682495 DOI: 10.1097/01.ccm.0000059440.44597.07] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Increased pulmonary blood flow is believed to contribute to the development of pulmonary hypertension. We investigated the effect of overcirculation via an aortocaval fistula, on the development of monocrotaline-induced pulmonary hypertension in rats. Monocrotaline was administered 1 wk after the creation of an aortocaval fistula. DESIGN Randomized, controlled study. SETTING Research laboratory of an academic institution. SUBJECTS Male Sprague-Dawley rats. INTERVENTIONS Overcirculation was induced by pneumonectomy and by surgical creation of aortocaval fistula. Pulmonary artery hypertension was induced by administration of monocrotaline. MEASUREMENTS AND MAIN RESULTS Aortic blood flow, Pao(2), and pulmonary arterial pressure were measured 4 wks later. A blinded investigator quantified pulmonary arterial neointimal formation in small pulmonary arteries. Compared with animals that received monocrotaline and/or underwent pneumonectomy but did not undergo aortocaval fistula, the presence of a surgical aortocaval fistula was associated with increased aortic blood flow (p <.001), increased Pao(2) (p <.001), and lower mean pulmonary arterial pressure (p <.001). In addition, rats with aortocaval fistula had less pulmonary arterial neointimal formation than matched animals without an aortocaval fistula (p =.034). CONCLUSIONS The presence of a surgical aortocaval fistula attenuates, rather than worsens, the development of monocrotaline-induced pulmonary hypertension in rats.
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MESH Headings
- Animals
- Aorta, Abdominal/diagnostic imaging
- Aorta, Abdominal/surgery
- Arteriovenous Shunt, Surgical
- Blood Flow Velocity
- Blood Pressure
- Cardiac Output
- Hypertension, Pulmonary/chemically induced
- Hypertension, Pulmonary/complications
- Hypertension, Pulmonary/pathology
- Hypertension, Pulmonary/physiopathology
- Hypertrophy, Right Ventricular/etiology
- Lung/blood supply
- Male
- Monocrotaline
- Pneumonectomy
- Pulmonary Artery/pathology
- Rats
- Rats, Sprague-Dawley
- Tunica Intima/pathology
- Ultrasonography, Doppler
- Vena Cava, Inferior/surgery
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Affiliation(s)
- Toshihiko Nishimura
- Division of Pulmonary and Critical Care Medicine, Stanford University Medical Center, 300 Pasteur Avenue, Stanford, CA 94305, USA
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Voelkel NF, Cool C, Taraceviene-Stewart L, Geraci MW, Yeager M, Bull T, Kasper M, Tuder RM. Janus face of vascular endothelial growth factor: the obligatory survival factor for lung vascular endothelium controls precapillary artery remodeling in severe pulmonary hypertension. Crit Care Med 2002; 30:S251-6. [PMID: 12004244 DOI: 10.1097/00003246-200205001-00013] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vascular endothelial growth factor (VEGF) plays a central role in the life and death of pulmonary vascular endothelial cells. Treatment of neonatal or adult rats with a VEGF receptor blocker destroys lung capillaries by inducing endothelial cell apoptosis and causes emphysema. Human lung tissue samples from patients with endstage emphysema have decreased levels of VEGF messenger RNA and protein and have decreased expression of kinase insert domain-containing receptor (VEGF receptor II). These decreases are associated with a high rate of alveolar septal cell apoptosis, indicating perhaps that decreased VEGF and kinase insert domain-containing receptor expression impairs endothelial cell survival in emphysematous lungs. Combination of VEGF receptor blockade with chronic hypoxia (3-wk exposure) results in obliteration of small precapillary pulmonary arteries by proliferating endothelial cells, severe pulmonary hypertension, and death caused by right-side heart failure. We propose that 1) VEGF receptor blockade causes endothelial cell apoptosis, 2) hypoxic vasoconstriction (shear stress) selects apoptosis-resistant endothelial cells that proliferate and obliterate the lumen, and 3) the vascular remodeling observed is relevant to the structural alterations that characterize severe pulmonary hypertension (including primary pulmonary hypertension) in humans. The endovascular cell growth in human disease and in our model exhibits some similarities with neoplastic cell growth. Chemotherapy strategies can now be employed in the animal model in an attempt to treat established vascular-obliterative lung disease.
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Affiliation(s)
- Norbert F Voelkel
- University of Colorado Health Sciences Center, Denver, CO 80262, USA.
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Medhora M, Bousamra M, Zhu D, Somberg L, Jacobs ER. Upregulation of collagens detected by gene array in a model of flow-induced pulmonary vascular remodeling. Am J Physiol Heart Circ Physiol 2002; 282:H414-22. [PMID: 11788387 DOI: 10.1152/ajpheart.00292.2001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently reported localized increased pulmonary arterial resistance, neointimal lesions, and medial thickening induced by aortopulmonary anastomosis in young pigs. This model was used to investigate changes in expression of genes potentially involved in pulmonary vascular remodeling employing a high throughput Atlas Human Cardiovascular Array carrying approximately 600 cardiovascular-related cDNA sequences. Data were confirmed by Northern analysis, Western blots, and histological examination. With the use of lower stringency conditions for hybridization, 56% of the 588 human genes on the array showed visible signal after autoradiography. Approximately 10% of the genes with visible hybridization were altered by shunt-induced high flow. Extracellular matrix and cell adhesion molecules were the most highly represented group of upregulated genes. To our knowledge, our data are the first to demonstrate flow-induced changes in gene expression using a combination of cross species cDNA arrays, homologous hybridization, immunospecific protein, and histology. Our observations expand the list of genes as putative candidates in pulmonary vascular remodeling and support the utility of cross-species microarray analysis in such applications.
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Affiliation(s)
- Meetha Medhora
- Department of Medicine and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Tuder RM, Zaiman AL. Prostacyclin analogs as the brakes for pulmonary artery smooth muscle cell proliferation: is it sufficient to treat severe pulmonary hypertension? Am J Respir Cell Mol Biol 2002; 26:171-4. [PMID: 11804866 DOI: 10.1165/ajrcmb.26.2.f230] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
MESH Headings
- Animals
- Antihypertensive Agents/chemistry
- Antihypertensive Agents/pharmacology
- Antihypertensive Agents/therapeutic use
- Cell Division/drug effects
- Epoprostenol/analogs & derivatives
- Epoprostenol/chemistry
- Epoprostenol/pharmacology
- Epoprostenol/physiology
- Humans
- Hypertension, Pulmonary/drug therapy
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/pathology
- Hypertension, Pulmonary/physiopathology
- Lung/metabolism
- Lung/pathology
- Models, Biological
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Pulmonary Artery/cytology
- Pulmonary Artery/drug effects
- Pulmonary Artery/metabolism
- Receptors, Epoprostenol
- Receptors, Prostaglandin/metabolism
- Signal Transduction/physiology
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Affiliation(s)
- Rubin M Tuder
- Division of Cardiopulmonary Pathology, Department of Pathology, The Johns Hopkins University School of Medicine, 720 Rutland Ave., Baltimore, MD 21205, USA.
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Jones PL, Chapados R, Baldwin HS, Raff GW, Vitvitsky EV, Spray TL, Gaynor JW. Altered hemodynamics controls matrix metalloproteinase activity and tenascin-C expression in neonatal pig lung. Am J Physiol Lung Cell Mol Physiol 2002; 282:L26-35. [PMID: 11741812 DOI: 10.1152/ajplung.00171.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tenascin-C (TN-C) expression and matrix metalloproteinase (MMP) activity are induced within remodeling pulmonary arteries (PAs), where they promote cell growth. Because pulmonary vascular disease in children with congenital heart defects is commonly associated with changes in pulmonary hemodynamics, we hypothesized that changes in pulmonary blood flow regulate TN-C and MMPs. To test this, we ligated the left PAs of neonatal pigs. After 12 wk, we evaluated the levels of TN-C and MMPs in control and ligated lung tissue. Modifying pulmonary hemodynamics increased TN-C mRNA and protein expression, MMP activity, and the DNA-binding activity of Egr-1, a transcription factor that has been shown to activate TN-C expression. To link MMP-mediated remodeling of the extracellular matrix to increased TN-C expression and Egr-1 activity, porcine PA smooth muscle cells were cultivated either on denatured type I collagen, which supported TN-C expression and Egr-1 activity, or on native collagen, which had the opposite effect. These data provide a framework for understanding how changes in pulmonary blood flow in the neonate modify the tissue microenvironment and cell behavior.
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Affiliation(s)
- Peter Lloyd Jones
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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Fouty BW, Grimison B, Fagan KA, Le Cras TD, Harral JW, Hoedt-Miller M, Sclafani RA, Rodman DM. p27(Kip1) is important in modulating pulmonary artery smooth muscle cell proliferation. Am J Respir Cell Mol Biol 2001; 25:652-8. [PMID: 11713109 DOI: 10.1165/ajrcmb.25.5.4592] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Vascular remodeling due to pulmonary arterial smooth muscle cell (PASMC) proliferation is central to the development of pulmonary hypertension. Cell proliferation requires the coordinated interaction of cyclins and cyclin-dependent kinases (cdk) to drive cells through the cell cycle. Cdk inhibitors can bind cyclin-cdk complexes and cause G(1) arrest. To determine the importance of the cdk inhibitor p27(Kip1) in PASMC proliferation we studied [(3)H]thymidine incorporation, changes in cell cycle, cell proliferation, and protein expression of p27(Kip1) following serum stimulation in early passage rat PASMC. p27(Kip1) expression decreased to 40% of baseline after serum stimulation, which was associated with an increase in both [(3)H]thymidine incorporation and the percent of cells in S phase. p27(Kip1) binding to cyclin E decreased at 24 h, and this correlated with an increase in phosphorylation of retinoblastoma both in vivo and in vitro. Overexpression of p27(Kip1) decreased [(3)H]thymidine incorporation and reduced cell counts at 5 d compared with controls. PASMC obtained from p27(Kip1-/-) mice showed a 2-fold increase in [(3)H]thymidine incorporation (at 24 h) and cell proliferation compared with p27(Kip1+/+) PASMC when cultured in 10% fetal bovine serum (FBS). These results suggest an important role for p27(Kip1) in regulating PASMC mitogenesis and proliferation.
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Affiliation(s)
- B W Fouty
- Center for Genetic Lung Disease and Division of Pulmonary Sciences and Critical Care Medicine, Department of Biochemistry, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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Tuder RM, Cool CD, Yeager M, Taraseviciene-Stewart L, Bull TM, Voelkel NF. The pathobiology of pulmonary hypertension. Endothelium. Clin Chest Med 2001; 22:405-18. [PMID: 11590837 DOI: 10.1016/s0272-5231(05)70280-x] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Dysfunctional endothelial cells have a central and critical role in the initiation and progression of severe pulmonary hypertension. The elucidation of the mechanisms involved in the control of endothelial cell proliferation and cell death in the pulmonary vasculature, therefore, is fundamentally important in the pathogenesis of severe pulmonary hypertension and of great interest for a better understanding of endothelial cell biology. Because the intravascular growth of endothelial cells resulting in tumorlets is unique to severe pulmonary hypertension, this phenomenon can teach researchers about the factors involved in the formation and maintenance of the normal endothelial cell monolayer. Clearly, in severe pulmonary hypertension, the "law of the endothelial cell monolayer" has been broken. The ultimate level of such a control is at the altered gene expression pattern that is conducive to endothelial cell growth and disruption of pulmonary blood flow. Secondary pulmonary hypertension certainly also is associated with proliferated pulmonary endothelial cells and plexiform lesions that are histologically indistinguishable from those in PPH. What is then the difference in the mechanisms of endothelial cell proliferation between primary and secondary pulmonary hypertension? The authors believe that PPH is a disease caused by somatic mutations in key angiogenesis- or apoptosis-related genes such as the TGF-beta receptor-2 and Bax. The loss of these important cell growth control mechanisms allows for the clonal expansion of endothelial cells from a single cell that has acquired a selective growth advantage. On the other hand, the proliferated endothelial cells in secondary pulmonary hypertension are polyclonal. It follows from this finding that local (vascular) factor(s) (such as increased shear stress), rather than mutations, play a major role in triggering endothelial cell proliferation. In PPH and secondary pulmonary hypertension, the researcher can postulate that the pulmonary vascular bed contains progenitor-like cells with the capacity of dysregulated growth. The main difference in the pathogenesis of primary and secondary pulmonary endothelial cell proliferation therefore may be the initial mechanism involved in the recruitment of an endothelial progenitor-like cell. In PPH, anorexigen-associated, and familial PPH, the proliferation of endothelial cells occurs from a mutated single cell, whereas in secondary pulmonary hypertension, several progenitor-like cells would be activated to grow. The abnormal endothelial cells in both forms of severe pulmonary hypertension expand because of the expression of angiogenesis-related molecules such as VEGF, VEGFR-2, HIF-1 alpha, and HIF-beta. Also important for the expansion of these cells is the down-regulation of expression of apoptosis-related mediators such as TGF-beta receptor-2 or Bax. The success of any therapy for severe pulmonary hypertension requires that the underlying process of endothelial cell proliferation could be controlled or reversed.
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Affiliation(s)
- R M Tuder
- Departments of Pathology, and Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA.
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O'Blenes SB, Fischer S, McIntyre B, Keshavjee S, Rabinovitch M. Hemodynamic unloading leads to regression of pulmonary vascular disease in rats. J Thorac Cardiovasc Surg 2001; 121:279-89. [PMID: 11174733 DOI: 10.1067/mtc.2001.111657] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Treatment options for patients with advanced pulmonary vascular disease caused by a congenital heart defect are still mainly limited to heart-lung transplantation or lung transplantation with repair of the cardiac lesion. Because we have previously shown that the structural changes associated with pulmonary hypertension can be reversed by stress unloading in an organ culture model, we now investigate whether hemodynamic unloading will lead to regression of pulmonary vascular disease in the intact animal. METHODS Right middle and lower lobectomy and monocrotaline injection were performed in Lewis rats (n = 22) to cause pulmonary vascular disease from a combined hemodynamic and toxic injury. Twenty-eight days later the left lungs were examined (n = 10) or exposed to normal pulmonary artery pressure for an additional 14 (n = 5) or 28 (n = 7) days by transplantation into healthy recipients. Pulmonary artery pressure, ventricular weight, and pulmonary artery morphology were evaluated in each group. RESULTS Pulmonary hypertension (50 vs 16 mm Hg; P <.001) and right ventricular hypertrophy (right ventricular/left ventricular weight 0.69 vs 0.32; P <.001) associated with pulmonary artery medial hypertrophy (28.2% vs 7.2% wall thickness; P <.001) and muscularization of small pulmonary arteries (92.3% vs 19.4%; P <.001) developed by day 28 (compared with untreated controls). However, transplantation into healthy recipients effectively unloaded the lungs (mean pulmonary artery pressure 17 and 24 mm Hg at 14 and 28 days after transplantation) and resulted in progressive normalization of medial hypertrophy (15.6% and 12.1% at 14 and 28 days) and muscularization (65.1% and 42.2% at 14 and 28 days) relative to nontransplanted controls (P <.005 in each case). CONCLUSIONS Hemodynamic unloading of lungs with pulmonary vascular disease results in progressive normalization of pulmonary artery structure. These results are the first to provide a rationale for attempting to induce regression of pulmonary vascular disease by pressure unloading of the pulmonary circulation. Methods to mechanically unload the pulmonary circulation should be critically evaluated as a strategy for staged surgical repair of congenital heart defects despite presumed irreversible pulmonary hypertension.
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Affiliation(s)
- S B O'Blenes
- Division of Cardiovascular Research, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada M5G 1X8
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Vieillard-Baron A, Frisdal E, Eddahibi S, Deprez I, Baker AH, Newby AC, Berger P, Levame M, Raffestin B, Adnot S, d'Ortho MP. Inhibition of matrix metalloproteinases by lung TIMP-1 gene transfer or doxycycline aggravates pulmonary hypertension in rats. Circ Res 2000; 87:418-25. [PMID: 10969041 DOI: 10.1161/01.res.87.5.418] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chronic hypoxic pulmonary hypertension (PH) results from persistent vasoconstriction, excess muscularization, and extracellular matrix remodeling of pulmonary arteries. The matrix metalloproteinases (MMPs) are a family of proteinases implicated in extracellular matrix turnover and hence in smooth muscle and endothelial cell migration and proliferation. Because MMP expression and activity are increased in PH, we designed the present study to investigate whether inhibition of lung MMPs in rats subjected to chronic hypoxia (CH) contributes to or protects against vascular remodeling and PH. To achieve lung MMP inhibition, rats exposed to 10% O(2) for 15 days were treated with either doxycycline (20 mg/kg per day by gavage starting 2 days before and continuing throughout the CH period) or a single dose of recombinant adenovirus (Ad) for the human tissue inhibitors of metalloproteinases-1 (hTIMP-1) gene (Ad.hTIMP-1, 10(8) plaque-forming units given intratracheally 2 days before CH initiation). Control groups either received no treatment or were treated with an adenovirus containing no gene in the expression cassette (Ad.Null). Efficacy of hTIMP-1 gene transfer was assessed both by ELISA on bronchoalveolar lavages and by hTIMP-1 immunofluorescence on lung sections. MMP inhibition in lungs was evaluated by in situ zymography and gelatinolytic activity assessment using [(3)H]gelatin. Rats treated with either doxycycline or Ad.hTIMP-1 had higher pulmonary artery pressure and right heart ventricular hypertrophy more severe than their respective controls. Worsening of PH was associated with increased muscularization and periadventitial collagen accumulation in distal arteries. In conclusion, our study provides compelling evidence that MMPs play a pivotal role in protecting against pulmonary artery remodeling.
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Qing F, McCarthy TJ, Markham J, Schuster DP. Pulmonary angiotensin-converting enzyme (ACE) binding and inhibition in humans. A positron emission tomography study. Am J Respir Crit Care Med 2000; 161:2019-25. [PMID: 10852783 DOI: 10.1164/ajrccm.161.6.9907036] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Angiotensin-converting enzyme (ACE) inhibition attenuates pulmonary hypertension and delays the development of pulmonary vascular remodeling in animal models. Thus, ACE inhibition might be a useful treatment for primary pulmonary hypertension (PPH). To determine the dose of ACE inhibitor required to specifically block pulmonary ACE in humans, we measured the combined forward rate constant (CFRC) for [(18)F]-fluorocaptopril, which is proportional to the mass of ACE in the lung, using positron emission tomography (PET). In five normal subjects, CFRC was measured twice, 1 wk apart, to assess measurement reproducibility. The CFRC was 0.151 +/- 0.067 for the first measurement and 0.140 +/- 0.060 for the second measurement (p = not significant [NS]). In five normals, CFRC decreased on average 84%, from 0.177 +/- 0.053/s to 0.028 +/- 0.017/s (p < 0.05), after 1 wk ingestion of 5 mg enalapril orally once a day (the scans were performed 24 h after the last medication). Similarly, in five patients with PPH, CFRC decreased on average 76%, from 0.052 +/- 0. 020/s to 0.012 +/- 0.003 (p < 0.01), after 1 wk enalapril, despite much lower baseline values. We conclude that the total mass of pulmonary ACE appears to be significantly reduced in PPH and that only low doses of ACE inhibitors may be needed to block the effects of ACE on vascular remodeling in PPH.
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Affiliation(s)
- F Qing
- Departments of Medicine and Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Jones FS, Jones PL. The tenascin family of ECM glycoproteins: structure, function, and regulation during embryonic development and tissue remodeling. Dev Dyn 2000; 218:235-59. [PMID: 10842355 DOI: 10.1002/(sici)1097-0177(200006)218:2<235::aid-dvdy2>3.0.co;2-g] [Citation(s) in RCA: 465] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The determination of animal form depends on the coordination of events that lead to the morphological patterning of cells. This epigenetic view of development suggests that embryonic structures arise as a consequence of environmental influences acting on the properties of cells, rather than an unfolding of a completely genetically specified and preexisting invisible pattern. Specialized cells of developing multicellular organisms are surrounded by a complex extracellular matrix (ECM), comprised largely of different collagens, proteoglycans, and glycoproteins. This ECM is a substrate for tissue morphogenesis, lends support and flexibility to mature tissues, and acts as an epigenetic informational entity in the sense that it transduces and integrates intracellular signals via distinct cell surface receptors. Consequently, ECM-receptor interactions have a profound influence on major cellular programs including growth, differentiation, migration, and survival. In contrast to many other ECM proteins, the tenascin (TN) family of glycoproteins (TN-C, TN-R, TN-W, TN-X, and TN-Y) display highly restricted and dynamic patterns of expression in the embryo, particularly during neural development, skeletogenesis, and vasculogenesis. These molecules are reexpressed in the adult during normal processes such as wound healing, nerve regeneration, and tissue involution, and in pathological states including vascular disease, tumorigenesis, and metastasis. In concert with a multitude of associated ECM proteins and cell surface receptors that include members of the integrin family, TN proteins impart contrary cellular functions, depending on their mode of presentation (i.e., soluble or substrate-bound) and the cell types and differentiation states of the target tissues. Expression of tenascins is regulated by a variety of growth factors, cytokines, vasoactive peptides, ECM proteins, and biomechanical factors. The signals generated by these factors converge on particular combinations of cis-regulatory elements within the recently identified TN gene promoters via specific transcriptional activators or repressors. Additional complexity in regulating TN gene expression is achieved through alternative splicing, resulting in variants of TN polypeptides that exhibit different combinations of functional protein domains. In this review, we discuss some of the recent advances in TN biology that provide insights into the complex way in which the ECM is regulated and how it functions to regulate tissue morphogenesis and gene expression.
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Affiliation(s)
- F S Jones
- Department of Neurobiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Jones FS, Jones PL. The tenascin family of ECM glycoproteins: Structure, function, and regulation during embryonic development and tissue remodeling. Dev Dyn 2000. [DOI: 10.1002/(sici)1097-0177(200006)218:2%3c235::aid-dvdy2%3e3.0.co;2-g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Kubo K, Ge RL, Koizumi T, Fujimoto K, Yamanda T, Haniuda M, Honda T. Pulmonary artery remodeling modifies pulmonary hypertension during exercise in severe emphysema. RESPIRATION PHYSIOLOGY 2000; 120:71-9. [PMID: 10786646 DOI: 10.1016/s0034-5687(00)00090-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To clarify the relation between the vessel remodeling and the physiology of pulmonary circulation in chronic obstructive pulmonary disease (COPD), we studied the pulmonary hemodynamics at rest and during exercise (25W) and the morphology of pulmonary arteries with external diameters of 100-200 microm in ten patients with severe emphysema. The wall thickness (WT) was defined as the intima plus media. The percent WT of the external diameter (% WT) in emphysema (36.0 +/- 4.3%) was significantly increased compared with that (22.6 +/- 3.3%) in five control lungs. The % WT was not related to pulmonary arterial pressure (Ppa) at rest, but was highly correlated with exercise Ppa (r = 0.721, P = 0.02) and with deltaPpa (Ppa during exercise-Ppa at rest) (r = 0.899, P = 0.0004). These findings suggest that pulmonary artery remodeling leads to reduced recruitability and distensibility of pulmonary vessels and is closely related to exercise pulmonary hypertension.
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Affiliation(s)
- K Kubo
- irst Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
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Botney MD. Role of hemodynamics in pulmonary vascular remodeling: implications for primary pulmonary hypertension. Am J Respir Crit Care Med 1999; 159:361-4. [PMID: 9927344 DOI: 10.1164/ajrccm.159.2.9805075] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- M D Botney
- Respiratory and Critical Care Division, Washington University Medical Center, St. Louis, Missouri, USA
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Schultze AE, Roth RA. Chronic pulmonary hypertension--the monocrotaline model and involvement of the hemostatic system. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 1998; 1:271-346. [PMID: 9776954 DOI: 10.1080/10937409809524557] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Monocrotaline (MCT) is a toxic pyrrolizidine alkaloid of plant origin. Administration of small doses of MCT or its active metabolite, monocrotaline pyrrole (MCTP), to rats causes delayed and progressive lung injury characterized by pulmonary vascular remodeling, pulmonary hypertension, and compensatory right heart hypertrophy. The lesions induced by MCT(P) administration in rats are similar to those observed in certain chronic pulmonary vascular diseases of people. This review begins with a synopsis of the hemostatic system, emphasizing the role of endothelium since endothelial cell dysfunction likely underlies the pathogenesis of MCT(P)-induced pneumotoxicity. MCT toxicology is discussed, focusing on morphologic, pulmonary mechanical, hemodynamic, and biochemical and molecular alterations that occur after toxicant exposure. Fibrin and platelet thrombosis of the pulmonary microvasculature occurs after administration of MCT(P) to rats, and several investigators have hypothesized that thrombi contribute to the lung injury and pulmonary hypertension. The evidence for involvement of the various components of the hemostatic system in MCT(P)-induced vascular injury and remodeling is reviewed. Current evidence is consistent with involvement of platelets and an altered fibrinolytic system, yet much remains to be learned about specific events and signals in the vascular pathogenesis.
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MESH Headings
- Animals
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/pathology
- Hemostasis/drug effects
- Humans
- Hypertension, Pulmonary/blood
- Hypertension, Pulmonary/chemically induced
- Hypertension, Pulmonary/etiology
- Hypertrophy, Right Ventricular/blood
- Hypertrophy, Right Ventricular/chemically induced
- Hypertrophy, Right Ventricular/etiology
- Monocrotaline/adverse effects
- Monocrotaline/analogs & derivatives
- Monocrotaline/toxicity
- Plants, Medicinal/adverse effects
- Plants, Toxic/adverse effects
- Rats
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Affiliation(s)
- A E Schultze
- Department of Pathology, College of Veterinary Medicine, University of Tennessee, Knoxville, USA
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Abstract
In many ways, the lung is an ideal organ for study with positron emission tomography (PET). First, structure-function relations are homogeneous over larger areas than in other organs (reducing problems associated with otherwise relatively poor spatial resolution and partial-volume averaging). Second, many physiologic and metabolic processes can be studied, including pulmonary blood flow, ventilation, vascular permeability, endothelial receptor and enzyme function, among others. A variety of radiotracers have been used to evaluate pulmonary blood flow with PET, including 68Ga- or 11C-albumin microspheres administered intravenously, H2 15O administered by i.v. infusion, and 13N-N2 administered by inhalation. Pulmonary ventilation has been evaluated with both 13N-N2 and 19Ne gas, also administered by inhalation. In general, the relative advantage of one approach over another depends on site-specific cyclotron capacity and experience, and on the nature and timing of concomitant studies with other positron-emitting radiopharmaceuticals. The various blood flow methods have been used primarily in studies of pulmonary gas exchange, in both experimental animals and in humans. Acute lung injury is usually defined by both an increase in extravascular water (pulmonary edema) and an increase in the permeability of the pulmonary endothelium to protein. Both processes can easily be evaluated with PET. Extravascular water is measured by a combination of scans with i.v. H2 15O and C15O. The latter is administered by inhalation to label the blood pool (to calculate intravascular water concentrations). Pulmonary vascular permeability has been evaluated with dynamic sequential imaging after either 68Ga-transferrin or 11C-methylalbumin infusions. The rate of uptake of either tracer into the pulmonary extravascular space is an index of "leakiness" of the pulmonary endothelium, and is quantified as the pulmonary transcapillary escape rate, or PTCER. PTCER appears to be a highly sensitive index of acute lung injury. Two receptor/ enzyme systems that have been evaluated include the beta-adrenergic receptor system (using 11CGP-12177 as the ligand) and angiotensin converting enzyme (using 18F-fluorocaptopril). In each case, the object is to measure Bmax, or the maximum binding-capacity for the ligand in question. Changes in Bmax can be used to infer changes in protein expression of the receptor or enzyme, or can be used to quantify adequacy of therapy with inhibitor drugs. Given the highly active nature of the pulmonary endothelium, it is likely that many other pulmonary receptor or enzyme systems can be studied in a similar fashion.
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Affiliation(s)
- D P Schuster
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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Okada K, Bernstein ML, Zhang W, Schuster DP, Botney MD. Angiotensin-converting enzyme inhibition delays pulmonary vascular neointimal formation. Am J Respir Crit Care Med 1998; 158:939-50. [PMID: 9731029 DOI: 10.1164/ajrccm.158.3.9710007] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Primary pulmonary hypertension (PPH) is a disease characterized pathologically by pulmonary artery medial hypertrophy, adventitial thickening, and neointimal proliferation. Increasing recognition of the importance of remodeling to the pathogenesis of PPH suggests new therapeutic possibilities, but it will be necessary to (1) identify essential mediators of remodeling, and (2) demonstrate that inhibiting those mediators suppresses remodeling before new antiremodeling therapies can be considered feasible. The effect of angiotensin-converting enzyme (ACE) inhibition on pulmonary vascular remodeling was studied in a newly developed rat model in which neointimal lesions develop between 3 and 5 wk after monocrotaline injury is coupled with increased pulmonary artery blood flow after contralateral pneumonectomy. Neointimal formation was significantly suppressed at 5 wk by ACE inhibition whether it was started 10 d before or 3 wk after remodeling was initiated, although medial hypertrophy and adventitial thickening still developed. By 11 wk, the extent of neointimal formation in rats treated with ACE inhibition was similar to rats without ACE inhibition at 5 wk. Pulmonary artery pressures and right ventricular weights correlated with the extent of neointimal formation. Northern blot analysis and in situ hybridization demonstrated marked suppression of lung tropoelastin and type I procollagen gene expression in the presence of ACE inhibition. An angiotensin II type I receptor antagonist partially, but not completely, replicated the effects of ACE inhibition. These data suggest that the tissue angiotensin system may be a target for therapeutic efforts to suppress the vascular remodeling that is characteristic of primary pulmonary hypertension.
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Affiliation(s)
- K Okada
- Respiratory and Critical Care Division, Washington University Medical Center, St. Louis, Missouri, USA
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Okada K, Tanaka Y, Bernstein M, Zhang W, Patterson GA, Botney MD. Pulmonary hemodynamics modify the rat pulmonary artery response to injury. A neointimal model of pulmonary hypertension. THE AMERICAN JOURNAL OF PATHOLOGY 1997; 151:1019-25. [PMID: 9327735 PMCID: PMC1858047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hemodynamic factors have profound influences on blood vessels. To test the hypothesis that hemodynamic conditions modify the pattern of remodeling in response to injury, monocrotaline (MCT) injury in Sprague-Dawley rats was followed 1 week later by left pneumonectomy to increase blood flow to the right lung. Right pulmonary artery remodeling in these MCT plus pneumonectomy animals was compared with animals receiving MCT or pneumonectomy alone. Neointimal changes developed in more than 90% of all right lung intra-acinar vessels 5 weeks after MCT injury (4 weeks after pneumonectomy). Neointimal lesions did not develop in untreated animals or in animals receiving MCT or pneumonectomy only. Animals with a neointimal pattern of remodeling developed severe right ventricular hypertrophy (RVH) whereas animals with a medial hypertrophy pattern of remodeling (MCT only) developed moderate RVH compared with control animals. Neointimal lesions and RVH were similar whether injury preceded pneumonectomy or vice versa. To exclude the possibility that neointimal lesions resulted from injury plus post-pneumonectomy compensatory lung growth, rather than injury plus increased flow, a left subclavian-pulmonary artery anastomosis was substituted for pneumonectomy. Neointimal lesions and severe RVH developed in these animals but were not seen in animals receiving either MCT or anastomosis only. These studies demonstrate an important role for hemodynamics in determining the pattern of pulmonary vascular remodeling after injury.
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Affiliation(s)
- K Okada
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
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