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Fang Q, Bai Y, Hu S, Ding J, Liu L, Dai M, Qiu J, Wu L, Rao X, Wang Y. Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling. Antioxidants (Basel) 2023; 12:1978. [PMID: 38001831 PMCID: PMC10669195 DOI: 10.3390/antiox12111978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/22/2023] [Accepted: 11/05/2023] [Indexed: 11/26/2023] Open
Abstract
Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.
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Affiliation(s)
- Qin Fang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yang Bai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Shuiqing Hu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Ding
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lei Liu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Meiyan Dai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Qiu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lujin Wu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoquan Rao
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
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Shimoda LA. Cellular Pathways Promoting Pulmonary Vascular Remodeling by Hypoxia. Physiology (Bethesda) 2021; 35:222-233. [PMID: 32490752 DOI: 10.1152/physiol.00039.2019] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Exposure to hypoxia increases pulmonary vascular resistance, leading to elevated pulmonary arterial pressure and, potentially, right heart failure. Vascular remodeling is an important contributor to the increased pulmonary vascular resistance. Hyperproliferation of smooth muscle, endothelial cells, and fibroblasts, and deposition of extracellular matrix lead to increased wall thickness, extension of muscle into normally non-muscular arterioles, and vascular stiffening. This review highlights intrinsic and extrinsic modulators contributing to the remodeling process.
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Affiliation(s)
- Larissa A Shimoda
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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The Role and Regulation of Pulmonary Artery Smooth Muscle Cells in Pulmonary Hypertension. Int J Hypertens 2020; 2020:1478291. [PMID: 32850144 PMCID: PMC7441461 DOI: 10.1155/2020/1478291] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 07/20/2020] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is one of the most devastating cardiovascular diseases worldwide and it draws much attention from numerous scientists. As an indispensable part of pulmonary artery, smooth muscle cells are worthy of being carefully investigated. To elucidate the pathogenesis of PH, several theories focusing on pulmonary artery smooth muscle cells (PASMC), such as hyperproliferation, resistance to apoptosis, and cancer theory, have been proposed and widely studied. Here, we tried to summarize the studies, concentrating on the role of PASMC in the development of PH, feasible molecular basis to intervene, and potential treatment to PH.
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Rieg AD, Suleiman S, Bünting NA, Verjans E, Spillner J, Schnöring H, Kalverkamp S, Schröder T, von Stillfried S, Braunschweig T, Schälte G, Uhlig S, Martin C. Levosimendan reduces segmental pulmonary vascular resistance in isolated perfused rat lungs and relaxes human pulmonary vessels. PLoS One 2020; 15:e0233176. [PMID: 32421724 PMCID: PMC7233573 DOI: 10.1371/journal.pone.0233176] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/29/2020] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Levosimendan is approved for acute heart failure. Within this context, pulmonary hypertension represents a frequent co-morbidity. Hence, the effects of levosimendan on segmental pulmonary vascular resistance (PVR) are relevant. So far, this issue has been not studied. Beyond that the relaxant effects of levosimendan in human pulmonary vessel are unknown. We addressed these topics in rats' isolated perfused lungs (IPL) and human precision-cut lung slices (PCLS). MATERIAL AND METHODS In IPL, levosimendan (10 μM) was perfused in untreated and endothelin-1 pre-contracted lungs. The pulmonary arterial pressure (PPA) was continuously recorded and the capillary pressure (Pcap) was determined by the double-occlusion method. Thereafter, segmental PVR, expressed as precapillary (Rpre) and postcapillary resistance (Rpost) and PVR were calculated. Human PCLS were prepared from patients undergoing lobectomy. Levosimendan-induced relaxation was studied in naïve and endothelin-1 pre-contracted PAs and PVs. In endothelin-1 pre-contracted PAs, the role of K+-channels was studied by inhibition of KATP-channels (glibenclamide), BKCa2+-channels (iberiotoxin) and Kv-channels (4-aminopyridine). All changes of the vascular tone were measured by videomicroscopy. In addition, the increase of cAMP/GMP due to levosimendan was measured by ELISA. RESULTS Levosimendan did not relax untreated lungs or naïve PAs and PVs. In IPL, levosimendan attenuated the endothelin-1 induced increase of PPA, PVR, Rpre and Rpost. In human PCLS, levosimendan relaxed pre-contracted PAs or PVs to 137% or 127%, respectively. In pre-contracted PAs, the relaxant effect of levosimendan was reduced, if KATP- and Kv-channels were inhibited. Further, levosimendan increased cGMP in PAs/PVs, but cAMP only in PVs. DISCUSSION Levosimendan reduces rats' segmental PVR and relaxes human PAs or PVs, if the pulmonary vascular tone is enhanced by endothelin-1. Regarding levosimendan-induced relaxation, the activation of KATP- and Kv-channels is of impact, as well as the formation of cAMP and cGMP. In conclusion, our results suggest that levosimendan improves pulmonary haemodynamics, if PVR is increased as it is the case in pulmonary hypertension.
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Affiliation(s)
- Annette Dorothea Rieg
- Department of Anaesthesiology, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
- * E-mail:
| | - Said Suleiman
- Institute of Pharmacology and Toxicology, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
| | - Nina Andrea Bünting
- Institute of Pharmacology and Toxicology, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
| | - Eva Verjans
- Department of Paediatrics, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
| | - Jan Spillner
- Department of Cardiac and Thoracic Surgery, Medical Faculty Aachen, Rhenish-Westphalian Technical University, Aachen, Germany
| | - Heike Schnöring
- Department of Cardiac and Thoracic Surgery, Medical Faculty Aachen, Rhenish-Westphalian Technical University, Aachen, Germany
| | - Sebastian Kalverkamp
- Department of Cardiac and Thoracic Surgery, Medical Faculty Aachen, Rhenish-Westphalian Technical University, Aachen, Germany
| | - Thomas Schröder
- Department of Surgery, Luisenhospital Aachen, Aachen, Germany
| | - Saskia von Stillfried
- Institute of Pathology, Medical Faculty Aachen, Rhenish-Westphalian Technical University, Aachen, Germany
| | - Till Braunschweig
- Institute of Pathology, Medical Faculty Aachen, Rhenish-Westphalian Technical University, Aachen, Germany
| | - Gereon Schälte
- Department of Anaesthesiology, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
| | - Stefan Uhlig
- Institute of Pharmacology and Toxicology, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
| | - Christian Martin
- Institute of Pharmacology and Toxicology, Medical Faculty Aachen, Rhenish Westphalian Technical University, Aachen, Germany
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van Duin RWB, Stam K, Cai Z, Uitterdijk A, Garcia-Alvarez A, Ibanez B, Danser AHJ, Reiss IKM, Duncker DJ, Merkus D. Transition from post-capillary pulmonary hypertension to combined pre- and post-capillary pulmonary hypertension in swine: a key role for endothelin. J Physiol 2018; 597:1157-1173. [PMID: 29799120 PMCID: PMC6375874 DOI: 10.1113/jp275987] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/11/2018] [Indexed: 12/31/2022] Open
Abstract
Key points Passive, isolated post‐capillary pulmonary hypertension (PH) secondary to left heart disease may progress to combined pre‐ and post‐capillary or ‘active’ PH This ‘activation’ of post‐capillary PH significantly increases morbidity and mortality, and is still incompletely understood. In this study, pulmonary vein banding gradually produced post‐capillary PH with structural and functional microvascular remodelling in swine. Ten weeks after banding, the pulmonary endothelin pathway was upregulated, likely contributing to pre‐capillary aspects in the initially isolated post‐capillary PH. Inhibition of the endothelin pathway could potentially stop the progression of early stage post‐capillary PH.
Abstract Passive, isolated post‐capillary pulmonary hypertension (IpcPH) secondary to left heart disease may progress to combined pre‐ and post‐capillary or ‘active’ PH (CpcPH) characterized by chronic pulmonary vascular constriction and remodelling. The mechanisms underlying this ‘activation’ of passive pulmonary hypertension (PH) remain incompletely understood. Here we investigated the role of the vasoconstrictor endothelin‐1 (ET) in the progression from IpcPH to CpcPH in a swine model for post‐capillary PH. Swine underwent pulmonary vein banding (PVB; n = 7) or sham‐surgery (Sham; n = 6) and were chronically instrumented 4 weeks later. Haemodynamics were assessed for 8 weeks, at rest and during exercise, before and after administration of the ET receptor antagonist tezosentan. After sacrifice, the pulmonary vasculature was investigated by histology, RT‐qPCR and myograph experiments. Pulmonary arterial pressure and resistance increased significantly over time. mRNA expression of prepro‐endothelin‐1 and endothelin converting enzyme‐1 in the lung was increased, while ETA expression was unchanged and ETB expression was downregulated. This was associated with increased plasma ET levels from week 10 onward and a more pronounced vasodilatation to in vivo administration of tezosentan at rest and during exercise. Myograph experiments showed decreased endothelium‐dependent vasodilatation to Substance P and increased vasoconstriction to KCl in PVB swine consistent with increased muscularization observed with histology. Moreover, maximal vasoconstriction to ET was increased whereas ET sensitivity was decreased. In conclusion, PVB swine gradually developed PH with structural and functional vascular remodelling. From week 10 onward, the pulmonary ET pathway was upregulated, likely contributing to pre‐capillary activation of the initially isolated post‐capillary PH. Inhibition of the ET pathway could thus potentially provide a pharmacotherapeutic target for early stage post‐capillary PH. Passive, isolated post‐capillary pulmonary hypertension (PH) secondary to left heart disease may progress to combined pre‐ and post‐capillary or ‘active’ PH This ‘activation’ of post‐capillary PH significantly increases morbidity and mortality, and is still incompletely understood. In this study, pulmonary vein banding gradually produced post‐capillary PH with structural and functional microvascular remodelling in swine. Ten weeks after banding, the pulmonary endothelin pathway was upregulated, likely contributing to pre‐capillary aspects in the initially isolated post‐capillary PH. Inhibition of the endothelin pathway could potentially stop the progression of early stage post‐capillary PH.
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Affiliation(s)
- Richard W B van Duin
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands
| | - Kelly Stam
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands
| | - Zongye Cai
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands
| | - André Uitterdijk
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands
| | - Ana Garcia-Alvarez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain.,Hospital Clinic of Barcelona, IDIBAPS, Barcelona, Spain
| | - Borja Ibanez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain.,IIS-Fundación Jiménez Díaz University Hospital, Madrid, Spain.,CIBERCV, Madrid, Spain
| | - A H Jan Danser
- Department of Pharmacology, Erasmus MC, Rotterdam, The Netherlands
| | - Irwin K M Reiss
- Pediatrics / Neonatology, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands
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Ghigna MR, Mooi WJ, Grünberg K. Pulmonary hypertensive vasculopathy in parenchymal lung diseases and/or hypoxia: Number 1 in the Series "Pathology for the clinician" Edited by Peter Dorfmüller and Alberto Cavazza. Eur Respir Rev 2017; 26:26/144/170003. [PMID: 28659502 DOI: 10.1183/16000617.0003-2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/01/2017] [Indexed: 01/01/2023] Open
Abstract
Pulmonary hypertension (PH) with complicating chronic lung diseases and/or hypoxia falls into group 3 of the updated classification of PH. Patients with chronic obstructive lung disease (COPD), diffuse lung disease (such as idiopathic pulmonary fibrosis (IPF)) and with sleep disordered breathing are particularly exposed to the risk of developing PH. Although PH in such a context is usually mild, a minority of patients exhibit severe haemodynamic impairment, defined by a mean pulmonary arterial pressure (mPAP) of ≥35 mmHg or mPAP values ranging between 25 mmHg and 35 mmHg with a low cardiac index (<2 L·min-1·m-2). The overlap between lung parenchymal disease and PH heavily affects life expectancy in such a patient population and complicates their therapeutic management. In this review we illustrate the pathological features and the underlying pathophysiological mechanisms of pulmonary circulation in chronic lung diseases, with an emphasis on COPD, IPF and obstructive sleep apnoea syndrome.
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Affiliation(s)
- Maria Rosa Ghigna
- Service d'Anatomie et de Cytologie Pathologiques, Hôpital Marie Lannelongue, Le Plessis Robinson, France
| | - Wolter J Mooi
- Dept of Pathology, VU University Medical Center, Amsterdam, The Netherlands
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Kandhi S, Zhang B, Froogh G, Qin J, Alruwaili N, Le Y, Yang YM, Hwang SH, Hammock BD, Wolin MS, Huang A, Sun D. EETs promote hypoxic pulmonary vasoconstriction via constrictor prostanoids. Am J Physiol Lung Cell Mol Physiol 2017; 313:L350-L359. [PMID: 28450284 DOI: 10.1152/ajplung.00038.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 12/20/2022] Open
Abstract
To test the hypothesis that epoxyeicosatrienoic acids (EETs) facilitate pulmonary responses to hypoxia, male wild-type (WT) and soluble-epoxide hydrolase knockout (sEH-KO) mice, and WT mice chronically fed a sEH inhibitor (t-TUCB; 1 mg·kg-1·day-1) were used. Right ventricular systolic pressure (RVSP) was recorded under control and hypoxic conditions. The control RVSP was comparable among all groups. However, hypoxia elicited increases in RVSP in all groups with predominance in sEH-KO and t-TUCB-treated mice. 14,15-EEZE (an EET antagonist) attenuated the hypoxia-induced greater elevation of RVSP in sEH-deficient mice, suggesting an EET-mediated increment. Exogenous 5,6-; 8,9-, or 14,15-EET (0.05 ng/g body wt) did not change RVSP in any conditions, but 11,12-EET enhanced RVSP under hypoxia. Isometric tension was recorded from pulmonary arteries isolated from WT and sEH-KO mice, vessels that behaved identically in their responsiveness to vasoactive agents and vessel stretch. Hypoxic pulmonary vasoconstriction (HPV, expressed as increases in hypoxic force) was significantly greater in vessels of sEH-KO than WT vessels; the enhanced component was inhibited by EEZE. Treatment of WT vessels with 11,12-EET enhanced HPV to the same level as sEH-KO vessels, confirming EETs as primary players. Inhibition of cyclooxygenases (COXs) significantly enhanced HPV in WT vessels, but attenuated HPV in sEH-KO vessels. Blocking/inhibiting COX-1, prostaglandin H2 (PGH2)/thromboxane A2 (TXA2) receptors and TXA synthase prevented the enhanced HPV in sEH-KO vessels but had no effects on WT vessels. In conclusion, an EET-dependent alteration in PG metabolism that favors the action of vasoconstrictor PGH2 and TXA2 potentiates HPV and hypoxia-induced elevation of RVSP in sEH-deficient mice.
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Affiliation(s)
- Sharath Kandhi
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Bin Zhang
- Department of Physiology, New York Medical College, Valhalla, New York.,Department of GI Surgery, Renji Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, People's Republic of China; and
| | - Ghezal Froogh
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Jun Qin
- Department of Physiology, New York Medical College, Valhalla, New York.,Department of GI Surgery, Renji Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, People's Republic of China; and
| | - Norah Alruwaili
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Yicong Le
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Yang-Ming Yang
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Sung Hee Hwang
- Department of Entomology and Nematology, and University of California Davis Comprehensive Cancer Center, University of California, Davis, California
| | - Bruce D Hammock
- Department of Entomology and Nematology, and University of California Davis Comprehensive Cancer Center, University of California, Davis, California
| | - Michael S Wolin
- Department of Physiology, New York Medical College, Valhalla, New York
| | - An Huang
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Dong Sun
- Department of Physiology, New York Medical College, Valhalla, New York;
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Huetsch JC, Suresh K, Bernier M, Shimoda LA. Update on novel targets and potential treatment avenues in pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2016; 311:L811-L831. [PMID: 27591245 PMCID: PMC5130539 DOI: 10.1152/ajplung.00302.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 08/29/2016] [Indexed: 02/08/2023] Open
Abstract
Pulmonary hypertension (PH) is a condition marked by a combination of constriction and remodeling within the pulmonary vasculature. It remains a disease without a cure, as current treatments were developed with a focus on vasodilatory properties but do not reverse the remodeling component. Numerous recent advances have been made in the understanding of cellular processes that drive pathologic remodeling in each layer of the vessel wall as well as the accompanying maladaptive changes in the right ventricle. In particular, the past few years have yielded much improved insight into the pathways that contribute to altered metabolism, mitochondrial function, and reactive oxygen species signaling and how these pathways promote the proproliferative, promigratory, and antiapoptotic phenotype of the vasculature during PH. Additionally, there have been significant advances in numerous other pathways linked to PH pathogenesis, such as sex hormones and perivascular inflammation. Novel insights into cellular pathology have suggested new avenues for the development of both biomarkers and therapies that will hopefully bring us closer to the elusive goal: a therapy leading to reversal of disease.
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Affiliation(s)
- John C Huetsch
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland; and
| | - Karthik Suresh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland; and
| | - Meghan Bernier
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland; and
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9
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Pathophysiology of Pulmonary Hypertension in Chronic Parenchymal Lung Disease. Am J Med 2016; 129:366-71. [PMID: 26706386 DOI: 10.1016/j.amjmed.2015.11.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 11/02/2015] [Accepted: 11/03/2015] [Indexed: 02/01/2023]
Abstract
Pulmonary hypertension commonly complicates chronic obstructive pulmonary disease and interstitial lung disease. The association of chronic lung disease and pulmonary hypertension portends a worse prognosis. The pathophysiology of pulmonary hypertension differs in the presence or absence of lung disease. We describe the physiological determinants of the normal pulmonary circulation to better understand the pathophysiological factors implicated in chronic parenchymal lung disease-associated pulmonary hypertension. This review will focus on the pathophysiology of 3 forms of chronic lung disease-associated pulmonary hypertension: idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, and sarcoidosis.
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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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Yousaf F, Spinowitz B. Hypoxia-Inducible Factor Stabilizers: a New Avenue for Reducing BP While Helping Hemoglobin? Curr Hypertens Rep 2016; 18:23. [DOI: 10.1007/s11906-016-0629-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Bertero T, Cottrill K, Krauszman A, Lu Y, Annis S, Hale A, Bhat B, Waxman AB, Chau BN, Kuebler WM, Chan SY. The microRNA-130/301 family controls vasoconstriction in pulmonary hypertension. J Biol Chem 2015; 290:2069-85. [PMID: 25505270 PMCID: PMC4303661 DOI: 10.1074/jbc.m114.617845] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/26/2014] [Indexed: 12/19/2022] Open
Abstract
Pulmonary hypertension (PH) is a complex disorder, spanning several known vascular cell types. Recently, we identified the microRNA-130/301 (miR-130/301) family as a regulator of multiple pro-proliferative pathways in PH, but the true breadth of influence of the miR-130/301 family across cell types in PH may be even more extensive. Here, we employed targeted network theory to identify additional pathogenic pathways regulated by miR-130/301, including those involving vasomotor tone. Guided by these predictions, we demonstrated, via gain- and loss-of-function experimentation in vitro and in vivo, that miR-130/301-specific control of the peroxisome proliferator-activated receptor γ regulates a panel of vasoactive factors communicating between diseased pulmonary vascular endothelial and smooth muscle cells. Of these, the vasoconstrictive factor endothelin-1 serves as an integral point of communication between the miR-130/301-peroxisome proliferator-activated receptor γ axis in endothelial cells and contractile function in smooth muscle cells. Thus, resulting from an in silico analysis of the architecture of the PH disease gene network coupled with molecular experimentation in vivo, these findings clarify the expanded role of the miR-130/301 family in the global regulation of PH. They further emphasize the importance of molecular cross-talk among the diverse cellular populations involved in PH.
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Affiliation(s)
- Thomas Bertero
- From the Divisions of Cardiovascular and Network Medicine and
| | | | - Adrienn Krauszman
- the Keenan Research Centre for Biomedical Science of St. Michael's, University of Toronto, Toronto, Ontario M5R 0A3, Canada
| | - Yu Lu
- From the Divisions of Cardiovascular and Network Medicine and
| | - Sofia Annis
- From the Divisions of Cardiovascular and Network Medicine and
| | - Andrew Hale
- From the Divisions of Cardiovascular and Network Medicine and
| | | | - Aaron B Waxman
- Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - B Nelson Chau
- Regulus Therapeutics, San Diego, California 92121, and
| | - Wolfgang M Kuebler
- the Keenan Research Centre for Biomedical Science of St. Michael's, University of Toronto, Toronto, Ontario M5R 0A3, Canada, the Department of Physiology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Stephen Y Chan
- From the Divisions of Cardiovascular and Network Medicine and
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Khamaisi M, Toukan H, Axelrod JH, Rosenberger C, Skarzinski G, Shina A, Meidan R, Koesters R, Rosen S, Walkinshaw G, Mimura I, Nangaku M, Heyman SN. Endothelin-converting enzyme is a plausible target gene for hypoxia-inducible factor. Kidney Int 2014; 87:761-70. [PMID: 25469848 DOI: 10.1038/ki.2014.362] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 09/05/2014] [Accepted: 09/11/2014] [Indexed: 11/09/2022]
Abstract
Renal endothelin-converting enzyme (ECE)-1 is induced in experimental diabetes and following radiocontrast administration, conditions characterized by renal hypoxia, hypoxia-inducible factor (HIF) stabilization, and enhanced endothelin synthesis. Here we tested whether ECE-1 might be a HIF-target gene in vitro and in vivo. ECE-1 transcription and expression increased in cultured vascular endothelial and proximal tubular cell lines, subject to hypoxia, to mimosine or cobalt chloride. These interventions are known to stabilize HIF signaling by inhibition of HIF-prolyl hydroxylases. In rats, HIF-prolyl-hydroxylase inhibition by mimosine or FG-4497 increased HIF-1α immunostaining in renal tubules, principally in distal nephron segments. This was associated with markedly enhanced ECE-1 protein expression, predominantly in the renal medulla. A progressive and dramatic increase in ECE-1 immunostaining over time, in parallel with enhanced HIF expression, was also noted in conditional von Hippel-Lindau knockout mice. Since HIF and STAT3 are cross-stimulated, we triggered HIF expression by STAT3 activation in mice, transfected by or injected with a chimeric IL-6/IL-6-receptor protein, and found a similar pattern of enhanced ECE-1 expression. Chromatin immunoprecipitation sequence (ChIP-seq) and PCR analysis in hypoxic endothelial cells identified HIF binding at the ECE-1 promoter and intron regions. Thus, our findings suggest that ECE-1 may be a novel HIF-target gene.
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Affiliation(s)
- Mogher Khamaisi
- Institute of Endocrinology, Diabetes & Metabolism, Rambam Medical Center & RB Rappaport Faculty of Medicine-Technion, Haifa, Israel
| | - Hala Toukan
- Institute of Endocrinology, Diabetes & Metabolism, Rambam Medical Center & RB Rappaport Faculty of Medicine-Technion, Haifa, Israel
| | - Jonathan H Axelrod
- Goldyne Savad Institute of Gene Therapy, Hebrew University, Hadassah Hospitals, Jerusalem, Israel
| | | | - Galia Skarzinski
- Department of Medicine, Hebrew University, Hadassah Hospitals, Jerusalem, Israel
| | - Ahuva Shina
- Department of Medicine, Hebrew University, Hadassah Hospitals, Jerusalem, Israel
| | - Rina Meidan
- Department of Animal Sciences, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Robert Koesters
- Department of Nephrology, Tenon Hospital, University Pierre et Marie Curie, Paris, France
| | - Seymour Rosen
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Imari Mimura
- Divisions of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan
| | - Masaomi Nangaku
- Divisions of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan
| | - Samuel N Heyman
- Department of Medicine, Hebrew University, Hadassah Hospitals, Jerusalem, Israel
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Genome wide expression analysis suggests perturbation of vascular homeostasis during high altitude pulmonary edema. PLoS One 2014; 9:e85902. [PMID: 24465776 PMCID: PMC3899118 DOI: 10.1371/journal.pone.0085902] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 12/06/2013] [Indexed: 01/08/2023] Open
Abstract
Background High altitude pulmonary edema (HAPE) is a life-threatening form of non-cardiogenic edema which occurs in unacclimatized but otherwise normal individuals within two to four days after rapid ascent to altitude beyond 3000 m. The precise pathoetiology and inciting mechanisms regulating HAPE remain unclear. Methodology/Principle findings We performed global gene expression profiling in individuals with established HAPE compared to acclimatized individuals. Our data suggests concurrent modulation of multiple pathways which regulate vascular homeostasis and consequently lung fluid dynamics. These pathways included those which regulate vasoconstriction through smooth muscle contraction, cellular actin cytoskeleton rearrangements and endothelial permeability/dysfunction. Some notable genes within these pathways included MYLK; rho family members ARGEF11, ARHGAP24; cell adhesion molecules such as CLDN6, CLDN23, PXN and VCAM1 besides other signaling intermediates. Further, several important regulators of systemic/pulmonary hypertension including ADRA1D, ECE1, and EDNRA were upregulated in HAPE. We also observed significant upregulation of genes involved in paracrine signaling through chemokines and lymphocyte activation pathways during HAPE represented by transcripts of TNF, JAK2, MAP2K2, MAP2K7, MAPK10, PLCB1, ARAF, SOS1, PAK3 and RELA amongst others. Perturbation of such pathways can potentially skew vascular homeostatic equilibrium towards altered vascular permeability. Additionally, differential regulation of hypoxia-sensing, hypoxia-response and OXPHOS pathway genes in individuals with HAPE were also observed. Conclusions/Significance Our data reveals specific components of the complex molecular circuitry underlying HAPE. We show concurrent perturbation of multiple pathways regulating vascular homeostasis and suggest multi-genic nature of regulation of HAPE.
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Adachi K, Soejoedono RD, Handharyani E, Inai M, Tsukamoto Y. Therapeutic Trial of an Endothelin Receptor Agonist for the Highly Pathogenic Avian Influenza A/H5N1 Virus Infection in Chicks. Health (London) 2014. [DOI: 10.4236/health.2014.619294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Abstract
In the lung, acute reductions in oxygen lead to hypoxic pulmonary vasoconstriction, whereas prolonged exposures to hypoxia result in sustained vasoconstriction, pulmonary vascular remodeling, and the development of pulmonary hypertension. Data from both human subjects and animal models implicate a role for hypoxia-inducible factors (HIFs), oxygen-sensitive transcription factors, in pulmonary vascular responses to both acute and chronic hypoxia. In this review, we discuss work from our laboratory and others supporting a role for HIF in modulating hypoxic pulmonary vasoconstriction and mediating hypoxia-induced pulmonary hypertension, identify some of the downstream targets of HIF, and assess the potential to pharmacologically target the HIF system.
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Affiliation(s)
- Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Wang J, Chen Y, Lin C, Jia J, Tian L, Yang K, Zhao L, Lai N, Jiang Q, Sun Y, Zhong N, Ran P, Lu W. Effects of chronic exposure to cigarette smoke on canonical transient receptor potential expression in rat pulmonary arterial smooth muscle. Am J Physiol Cell Physiol 2013; 306:C364-73. [PMID: 24336649 DOI: 10.1152/ajpcell.00048.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To clarify the possible mechanism of cigarette smoke (CS)-induced pulmonary hypertension and furthermore provide effective targets for prevention and treatment, the effects of chronic CS on rat pulmonary arterial smooth muscle in vivo and nicotine treatment on rat pulmonary arterial smooth muscle cells (PASMCs) in vitro were investigated. In this study, we demonstrated that chronic CS exposure led to rat weight loss, right ventricular hypertrophy, and pulmonary arterial remodeling. A fluorescence microscope was used to measure intracellular calcium concentration ([Ca(2+)]i) in rat distal PASMCs. Results showed that basal [Ca(2+)]i and store-operated calcium entry (SOCE) levels in PASMCs from 3- and 6-mo CS-exposed rats were markedly higher than those in cells from the unexposed control animals (the increases in 6-mo CS group were more significant than that in 3-mo group), accompanied with increased canonical transient receptor potential 1 (TRPC1) and TRPC6 expression at both mRNA and protein levels in isolated distal PA. Simultaneously, in vitro study showed that nicotine treatment (10 nM) significantly increased basal [Ca(2+)]i and SOCE and upregulated TRPC1 and TRPC6 expression in cultured rat distal PASMCs. TRPC siRNA knockdown strategies revealed that the elevations of basal [Ca(2+)]i and SOCE induced by nicotine in PASMCs were TRPC1 and TRPC6 dependent. These results suggested that chronic CS-induced changes in vascular tone and structure in PA and the development of pulmonary hypertension might be largely due to upregulation of TRPC1 and TRPC6 expression in PASMCs, in which nicotine played an important role.
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Affiliation(s)
- Jian Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
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18
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Taylor BJ, Mojica CR, Olson TP, Woods PR, Frantz RP, Johnson BD. A possible role for systemic hypoxia in the reactive component of pulmonary hypertension in heart failure. J Card Fail 2013; 19:50-9. [PMID: 23273594 DOI: 10.1016/j.cardfail.2012.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 10/12/2012] [Accepted: 11/13/2012] [Indexed: 11/17/2022]
Abstract
BACKGROUND The mechanisms underlying the reactive component of pulmonary hypertension (PH) in heart failure (HF) are unclear. We examined whether resting systemic oxygen levels are related to pulmonary hemodynamics in HF. METHODS AND RESULTS Thirty-nine HF patients underwent right heart catheterization. Subsequently, patients were classified as having: 1) no PH (n = 12); 2) passive PH (n = 10); or 3) reactive PH (n = 17). Blood was drawn from the radial and pulmonary arteries for the determination of PaO(2), SaO(2), PvO(2), SvO(2), and vasoactive neurohormones. PaO(2) and PvO(2) were lower in reactive PH versus no PH and passive PH patients (65.3 ± 8.6 vs 78.3 ± 11.4 mm Hg and 74.5 ± 14.0 mm Hg; 29.2 ± 4.1 vs 36.2 ± 2.8 mm Hg and 33.4 ± 2.3 mm Hg; P < .05). SaO(2) and SvO(2) were lower in reactive PH versus no PH patients (93 ± 3% vs 96 ± 3%; 51 ± 11% vs 68 ± 4%; P < .05), but not different versus passive PH patients. The transpulmonary pressure gradient (TPG) was inversely related to PaO(2), PvO(2), SaO(2), and SvO(2) in the reactive PH patients only (r ≤ -0.557; P < .05). Similarly, plasma endothelin-1 correlated with PaO(2), PvO(2), SvO(2) (r ≤ -0.495), and TPG (r = 0.662; P < .05) in reactive PH patients only. CONCLUSIONS Systemic hypoxia may play a role in the reactive component of PH in HF, potentially via a hypoxia-induced increase in endothelial release of the vasoconstrictor endothelin-1.
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Affiliation(s)
- Bryan J Taylor
- Division of Cardiovascular Diseases, College of Medicine, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
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19
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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: 168] [Impact Index Per Article: 15.3] [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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20
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Skovgaard N, Olson KR. Hydrogen sulfide mediates hypoxic vasoconstriction through a production of mitochondrial ROS in trout gills. Am J Physiol Regul Integr Comp Physiol 2012; 303:R487-94. [PMID: 22739350 DOI: 10.1152/ajpregu.00151.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is an adaptive response that diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts. This response is important for the local matching of blood perfusion to ventilation and improves pulmonary gas exchange efficiency. HPV is an ancient and highly conserved response, expressed in the respiratory organs of all vertebrates, including lungs of mammals, birds, and reptiles; amphibian skin; and fish gills. The mechanism underlying HPV and how cells sense low Po(2) remains elusive. In perfused trout gills (Oncorhynchus mykiss), acute hypoxia, as well as H(2)S, caused an initial and transient constriction of the vasculature. Inhibition of the enzymes cystathionine-β-synthase and cystathionine-γ-lyase, which blocks H(2)S production, abolished the hypoxic response. Individually blocking the four complexes in the electron transport chain abolished both the hypoxic and the H(2)S-mediated constriction. Glutathione, an antioxidant and scavenger of superoxide, attenuated the vasoconstriction in response to hypoxia and H(2)S. Furthermore, diethyldithiocarbamate, an inhibitor of superoxide dismutase, attenuated the hypoxic and H(2)S constriction. This strongly suggests that H(2)S mediates the hypoxic vasoconstriction in trout gills. H(2)S may stimulate the mitochondrial production of superoxide, which is then converted to hydrogen peroxide (H(2)O(2)). Thus, H(2)O(2) may act as the "downstream" signaling molecule in hypoxic vasoconstriction.
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Affiliation(s)
- Nini Skovgaard
- Zoophysiology, Department of Bioscience, Aarhus University, C.F. Møllers Allé, DK-8000 Aarhus C, Denmark.
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21
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Connolly MJ, Aaronson PI. Key role of the RhoA/Rho kinase system in pulmonary hypertension. Pulm Pharmacol Ther 2010; 24:1-14. [PMID: 20833255 DOI: 10.1016/j.pupt.2010.09.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 07/06/2010] [Accepted: 09/02/2010] [Indexed: 02/06/2023]
Abstract
Pulmonary hypertension (PH) is a general term comprising a spectrum of pulmonary hypertensive disorders which have in common an elevation of mean pulmonary arterial pressure (mPAP). The prototypical form of the disease, termed pulmonary arterial hypertension (PAH), is a rare but lethal syndrome with a complex aetiology characterised by increased pulmonary vascular resistance (PVR) and progressive elevation of mPAP; patients generally die from heart failure. Current therapies are inadequate and median survival is less than three years. PH due to chronic hypoxia (CH) is a condition separate from PAH and is strongly associated with chronic obstructive pulmonary disease (COPD). An early event in the pathogenesis of this form of PH is hypoxic pulmonary vasoconstriction (HPV), an acute homeostatic process that maintains the ventilation-perfusion ratio during alveolar hypoxia. The mechanisms underlying HPV remain controversial, but RhoA/Rho kinase (ROK)-mediated Ca²+-sensitisation is considered important. Increasing evidence also implicates RhoA/ROK in PASMC proliferation, inflammatory cell recruitment and the regulation of cell motility, all of which are involved in the pulmonary vascular remodelling occurring in all forms of PH. ROK is therefore a potential therapeutic target in treating PH of various aetiologies. Here, we examine current concepts regarding the aetiology of PAH and also PH due to CH, focusing on the contribution that RhoA/ROK-mediated processes may make to their development and on ROK inhibitors as potential therapies.
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Affiliation(s)
- Michelle J Connolly
- Division of Asthma, Allergy and Lung Biology, School of Medicine, King's College London, United Kingdom.
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22
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Aoshima D, Murata T, Hori M, Ozaki H. Time-dependent phenotypic and contractile changes of pulmonary artery in chronic hypoxia-induced pulmonary hypertension. J Pharmacol Sci 2009; 110:182-90. [PMID: 19498269 DOI: 10.1254/jphs.09059fp] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Phenotypic and contractile changes in pulmonary arterial smooth muscle cells (PASMCs) were examined in rats with pulmonary hypertension induced by hypoxia. Exposure to hypoxia induced pulmonary hypertension within 1-4 weeks. Staining with BrdU revealed that proliferative activities of PASMCs peaked at 1 week of hypoxic exposure, and then moderate proliferative activity was maintained for the next 2-4 weeks. The beta-actin/alpha-actin ratio also increased at 1-2 weeks of exposure to hypoxia. Absolute contractility of the pulmonary arterial ring continuously decreased during hypoxia, whereas the basal active tonus of the pulmonary artery increased at 1-3 weeks. Nicardipine, the ETA-receptor antagonis, CI-1034 and the rho-kinase inhibitor Y27632 partially inhibited the elevated active tonus. Endothelin-1 content in the pulmonary hypertensive lung was continuously increased during exposure to hypoxia. In conclusion, the hypoxia-induced proliferative activity of PASMCs comprised a transient phase followed by a sustained phase. The change in PASMCs from a contractile to a synthetic phenotype also correlated with proliferative activity, which subsequently decreased PASMC contractility. The continuous production of endothelin-1 upon hypoxic exposure might contribute to the increased basal tonus of the pulmonary arterial wall, which might subsequently increase pulmonic arterial pressure, resulting in accelerated pulmonary hypertension.
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Affiliation(s)
- Daigo Aoshima
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, University of Tokyo, Tokyo, Japan
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23
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Talbot N, Balanos G, Robbins P, Dorrington K. Can intravenous endothelin-1 be used to enhance hypoxic pulmonary vasoconstriction in healthy humans? Br J Anaesth 2008; 101:466-72. [DOI: 10.1093/bja/aen214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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24
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Skovgaard N, Zibrandtsen H, Laursen BE, Simonsen U, Wang T. Hypoxia-induced vasoconstriction in alligator (Alligator mississippiensis) intrapulmonary arteries: a role for endothelin-1? J Exp Biol 2008; 211:1565-70. [DOI: 10.1242/jeb.014662] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Hypoxic pulmonary vasoconstriction (HPV) is an adaptive response that diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to better ventilated parts, matching blood perfusion to ventilation. HPV is an ancient and highly conserved response expressed in the respiratory organs of all vertebrates. However, the underlying mechanism and the role of the endothelium remain elusive. Isolated intrapulmonary arteries (internal diameter <346 μm) from the American alligator Alligator mississippiensis were mounted in microvascular myographs for isometric tension recording. Resting vessels and vessels contracted with either serotonin (5-HT) or endothelin-1 (ET-1) were exposed to sustained (45 min)hypoxia (PO2<5 mmHg). In ET-1-contracted vessels, hypoxia induced a monophasic, sustained and fully reversible constriction, which was independent of the endothelium. In relaxed or in 5-HT-contracted vessels, hypoxia did not cause constriction. The effects of ET-1, ETA and ETB as well as the general ET-receptor antagonist were studied. ET-1 caused a contraction of the pulmonary arteries through stimulation of ETA-receptors. ETA and ETB immunoreactive staining revealed the location of both receptors in the smooth muscle layer and of ETB receptors in the endothelium. In conclusion, because precontraction with serotonin did not facilitate HPV,the required precontraction in alligators seems specific to ET-1, which implies that ET-1 plays an important permissive role for the HPV response in alligators.
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Affiliation(s)
- Nini Skovgaard
- Zoophysiology, Department of Biological Sciences, University of Aarhus,Building 1131, 8000 Aarhus C, Denmark
- Department of Pharmacology, University of Aarhus, Denmark
| | | | | | - Ulf Simonsen
- Department of Pharmacology, University of Aarhus, Denmark
| | - Tobias Wang
- Zoophysiology, Department of Biological Sciences, University of Aarhus,Building 1131, 8000 Aarhus C, Denmark
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25
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Endothelin-1 and serotonin are involved in activation of RhoA/Rho kinase signaling in the chronically hypoxic hypertensive rat pulmonary circulation. J Cardiovasc Pharmacol 2008; 50:697-702. [PMID: 18091588 DOI: 10.1097/fjc.0b013e3181593774] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We have previously reported that vasoconstrictor sensitivity to KCl (a receptor-independent and voltage-gated Ca influx-mediated vasoconstrictor) is augmented in the chronically hypoxic hypertensive rat pulmonary circulation probably through increased Rho kinase-mediated Ca sensitization. However, the upstream mechanism by which the RhoA/Rho kinase signaling pathway is activated is unknown. This study examined if endogenous endothelin-1 (ET-1) and serotonin (5-HT) play roles in the Rho kinase-mediated augmented vasoconstrictor response to KCl and the activation of RhoA in chronically hypoxic hypertensive rat pulmonary arteries. The augmented KCl vasoconstriction in hypertensive lungs was reduced by the ETA receptor antagonist BQ123, while a dual ETA/B antagonist had no further effects. A combination of BQ123 and a 5-HT1B/1D receptor antagonist, GR127935, was more effective than either agent alone. The combined antagonists also reduced augmented contractile sensitivity to KCl in hypertensive intrapulmonary arteries. Membrane-to-cytosol ratio of RhoA expression in hypertensive arteries was greater than that in normotensive arteries and was reduced by BQ123 and GR127935. These results suggest that stimulation of ETA and 5-HT1B/1D receptors by endogenous ET-1 and 5-HT, respectively, is involved in RhoA/Rho kinase-mediated increased Ca sensitization in the chronically hypoxic hypertensive rat pulmonary circulation.
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26
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Russell MJ, Dombkowski RA, Olson KR. Effects of hypoxia on vertebrate blood vessels. ACTA ACUST UNITED AC 2008; 309:55-63. [DOI: 10.1002/jez.427] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Bonnet S, Archer SL. Potassium channel diversity in the pulmonary arteries and pulmonary veins: implications for regulation of the pulmonary vasculature in health and during pulmonary hypertension. Pharmacol Ther 2007; 115:56-69. [PMID: 17583356 DOI: 10.1016/j.pharmthera.2007.03.014] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 03/28/2007] [Indexed: 12/15/2022]
Abstract
This review describes the ionic heterogeneity manifest in the pulmonary circulation, particularly as it pertains to hypoxic pulmonary vasoconstriction (HPV) and pulmonary arterial hypertension (PAH). Heterogeneity in potassium (K(+)) channels, key regulators of vascular tone, cell proliferation, and apoptosis rates, contribute to the diverse response of vascular segments to hypoxia and to the localization of pathological changes in PAH. Pulmonary artery (PA) and pulmonary vein (PV) smooth muscle cells (SMC) express several K(+) channel families, including calcium-sensitive (KCa), voltage-gated (K(v)), inward rectifier (Kir), and 2-pore channels. Diversity is created by heterogeneous occurrence of alternatively spliced, mRNA species, assembly of heterotetrameric channels from diverse alpha-subunits, and association of channels with regulatory beta-subunits. Local heterogeneity in transcription factor activity may underlie differences in channel expression. Enrichment of resistance PASMCs with O(2)-sensitive K(+) channels, such as K(v)1.5, partially explains the greater HPV in resistance versus conduit PAs. In addition, resistance PAs are unique in having mitochondria which dynamically alter production of reactive O(2) species (ROS) in proportion to PO(2), thereby regulating K(+) channel activity and controlling expression through transcription factors, such as HIF-1alpha. In intraparenchymal PVs, a coaxial layer of cardiomyocytes encompasses a media of typical vascular SMCs. PV cardiomyocytes have rhythmic contraction and their Kir-enriched channels may be relevant to genesis of atrial arrhythmias and pulmonary edema. K(v) channel expression is decreased in PAH, leading to elevations of cytosolic K(+) and Ca(2+) that impair apoptosis and increase proliferation. Understanding ionic diversity may allow development of therapies that locally increase K(+) channel current and expression to treat PHT.
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Affiliation(s)
- Sébastien Bonnet
- Department of Medicine (Cardiology), University of Alberta, Edmonton, Canada
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28
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Weissmann N, Dietrich A, Fuchs B, Kalwa H, Ay M, Dumitrascu R, Olschewski A, Storch U, Mederos y Schnitzler M, Ghofrani HA, Schermuly RT, Pinkenburg O, Seeger W, Grimminger F, Gudermann T. Classical transient receptor potential channel 6 (TRPC6) is essential for hypoxic pulmonary vasoconstriction and alveolar gas exchange. Proc Natl Acad Sci U S A 2006; 103:19093-8. [PMID: 17142322 PMCID: PMC1748182 DOI: 10.1073/pnas.0606728103] [Citation(s) in RCA: 239] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Regional alveolar hypoxia causes local vasoconstriction in the lung, shifting blood flow from hypoxic to normoxic areas, thereby maintaining gas exchange. This mechanism is known as hypoxic pulmonary vasoconstriction (HPV). Disturbances in HPV can cause life-threatening hypoxemia whereas chronic hypoxia triggers lung vascular remodeling and pulmonary hypertension. The signaling cascade of this vitally important mechanism is still unresolved. Using transient receptor potential channel 6 (TRPC6)-deficient mice, we show that this channel is a key regulator of acute HPV as this regulatory mechanism was absent in TRPC6(-/-) mice whereas the pulmonary vasoconstrictor response to the thromboxane mimetic U46619 was unchanged. Accordingly, induction of regional hypoventilation resulted in severe arterial hypoxemia in TRPC6(-/-) but not in WT mice. This effect was mirrored by a lack of hypoxia-induced cation influx and currents in smooth-muscle cells from precapillary pulmonary arteries (PASMC) of TRPC6(-/-) mice. In both WT and TRPC6(-/-) PASMC hypoxia caused diacylglycerol (DAG) accumulation. DAG seems to exert its action via TRPC6, as DAG kinase inhibition provoked a cation influx only in WT but not in TRPC6(-/-) PASMC. Notably, chronic hypoxia-induced pulmonary hypertension was independent of TRPC6 activity. We conclude that TRPC6 plays a unique and indispensable role in acute hypoxic pulmonary vasoconstriction. Manipulation of TRPC6 function may thus offer a therapeutic strategy for the control of pulmonary hemodynamics and gas exchange.
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Affiliation(s)
- Norbert Weissmann
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
- To whom correspondence may be addressed. E-mail:
or
| | - Alexander Dietrich
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany; and
- To whom correspondence may be addressed. E-mail:
or
| | - Beate Fuchs
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Hermann Kalwa
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany; and
| | - Mahmut Ay
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Rio Dumitrascu
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Andrea Olschewski
- Department of Anesthesiology, Intensive Care Medicine, Pain Therapy, Justus-Liebig-University, 35392 Giessen, Germany
| | - Ursula Storch
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany; and
| | - Michael Mederos y Schnitzler
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany; and
| | - Hossein Ardeschir Ghofrani
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Ralph Theo Schermuly
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Olaf Pinkenburg
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany; and
| | - Werner Seeger
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Friedrich Grimminger
- *University of Giessen Lung Center (UGLC), Department of Internal Medicine II/V, Klinikstrasse 36, 35392 Giessen, Germany
| | - Thomas Gudermann
- Institute for Pharmacology and Toxicology, School of Medicine, University of Marburg, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany; and
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Robertson TP. Point: release of an endothelium-derived vasoconstrictor and RhoA/Rho kinase-mediated calcium sensitization of smooth muscle cell contraction are/are not the main effectors for full and sustained hypoxic pulmonary vasoconstriction. J Appl Physiol (1985) 2006; 102:2071-2; discussion 2075-6. [PMID: 17095630 DOI: 10.1152/japplphysiol.01258.2006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Tom P Robertson
- Department of Physiology, The University of Georgia, Athens, USA.
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Wareing M, Greenwood SL, Baker PN. Reactivity of human placental chorionic plate vessels is modified by level of oxygenation: differences between arteries and veins. Placenta 2006; 27:42-8. [PMID: 16310036 DOI: 10.1016/j.placenta.2004.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 11/09/2004] [Accepted: 11/10/2004] [Indexed: 11/30/2022]
Abstract
Normal fetal development in utero is dependent upon adequate perfusion of the placental vasculature, yet how fetoplacental blood flow is matched to maternal blood flow is unknown. In the perfused placental cotyledon in vitro, reduced oxygenation promotes vasoconstriction, which may act to direct blood in fetoplacental vessels to effectively perfused regions of the intervillus space. We aimed to demonstrate that oxygen tension could directly modify placental chorionic plate vessel vasoreactivity. Small arteries and veins from the chorionic plate were dissected from biopsies from term placentae of uncomplicated pregnancies and studied using parallel wire myography. Chorionic artery and vein vasoconstriction in 20%, 7% and 2% oxygen was assessed utilizing the thromboxane-mimetic U46619. Reduced oxygenation increased arterial maximal active effective pressure production and sensitivity to U46619. This effect was cyclo-oxygenase independent. In veins, modified oxygenation did not alter vasoconstriction. Vasodilatation in response to the NO donor sodium nitroprusside was increased in lowered oxygenation in veins but not in arteries. We suggest that modified oxygenation may play a role in the control of the blood flow in the fetoplacental circulation.
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Affiliation(s)
- M Wareing
- Maternal and Fetal Health Research Centre, University of Manchester, St. Mary's Hospital, Hathersage Road, Manchester M13 0JH, UK.
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Abstract
Recently, the mitochondria have become the focus of attention as the site of O(2) sensing underlying hypoxic pulmonary vasoconstriction (HPV). However, two disparate models have emerged to explain how mitochondria react to a decrease in Po(2). One model proposes that a drop in Po(2) decreases the rate of mitochondrial reactive oxygen species (ROS) generation, resulting in a decrease in oxidant stress and an accumulation of reducing equivalents. The resulting shift of the cytosol to a reduced state causes the inhibition of voltage-dependent potassium channels, membrane depolarization, and the influx of calcium through voltage-gated (L-type) calcium channels. A second and opposing model suggests that hypoxia triggers a paradoxical increase in a mitochondrial-induced ROS signal. The resulting shift of the cytosol to an oxidized state triggers the release of intracellular calcium stores, recruitment of calcium channels in the plasma membrane, and activation of contraction. This article summarizes the potential involvement of a mitochondria-induced ROS signal in these two very different models.
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Affiliation(s)
- Gregory B Waypa
- Dept. of Medicine MC6026, The University of Chicago, 5841 South Maryland Ave., Chicago, IL 60637, USA
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Abstract
Pulmonary veins have been seen primarily as conduit vessels; however, over the past two decades, a large amount of evidence has accumulated to indicate that pulmonary veins can exhibit substantial vasoactivity. In this review, the role of veins in regulation of the pulmonary circulation, particularly during the perinatal period and under certain pathophysiological conditions, is discussed. In the fetus, pulmonary veins contribute a significant fraction to total pulmonary vascular resistance. At birth, the veins as well as the arteries relax in response to endothelium-derived nitric oxide and dilator prostaglandins, thereby assisting in the fall in pulmonary vascular resistance. These effects are oxygen dependent and modulated by cGMP-dependent protein kinase. Under chronic hypoxic conditions, pulmonary veins undergo remodeling and demonstrate substantial constriction and hypertrophy. In a number of species, including the human, pulmonary veins are also the primary sites of action of certain vasoconstrictors such as endothelin and thromboxane. In various pathological conditions, there is an increased synthesis of these vasoactive agents that may lead to pulmonary venous constriction, increased microvascular pressures for fluid filtration, and formation of pulmonary edema. In conclusion, the significant role of veins in regulation of the pulmonary circulation needs to be appreciated to better prevent, diagnose, and treat lung disease.
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Affiliation(s)
- Yuansheng Gao
- Division of Neonatology, Department of Pediatrics, Harbor-UCLA Research and Education Institute, 1124 W. Carson St., RB-1, Torrance, CA 90502, USA
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Cermik TF, Altiay G, Firat MF, Hatipoglu ON, Berkarda S. Assessment of Tc-99m sestamibi tumor tissue uptake under the influence of increased arterial oxygen saturation. Nucl Med Biol 2005; 32:165-70. [PMID: 15721762 DOI: 10.1016/j.nucmedbio.2004.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Revised: 11/15/2004] [Accepted: 12/05/2004] [Indexed: 10/25/2022]
Abstract
The aim of this study is to investigate the potential effect of increased arterial saturation of oxygen in the magnitude of technetium-99m-hexakis-isobutyl-isonitrile (99mTc-MIBI) uptake in tumor tissue and to compare the results with those of conventional 99mTc-MIBI tumor imaging in the same patient with lung cancer. A total of 26 lung cancer patients underwent initial SPECT (I-SPECT) and after oxygen inhalation SPECT (O2-SPECT). The early (ER) and delayed ratios (DR) of O2-SPECT mean+/-S.D. were significantly higher than those of I-SPECT mean+/-S.D. (2.07+/-0.57 vs. 1.90+/-0.48 and 2.02+/-0.45 vs. 1.83+/-0.39, respectively). There are increased rates for the relative tumor uptake of 99mTc-MIBI by 9% for ER and 10% for DR on the O2-SPECT compared to I-SPECT. We found that 99mTc-MIBI uptake increased significantly in the tumor tissue with O2-SPECT compared to I-SPECT. In conclusion, 99mTc-MIBI scintigraphy is one of the main methods for differentiating viable and nonviable tissue fractions in tumors. We consider that 99mTc-MIBI uptake increase after oxygen inhalation is an indicator of positive acute cellular response of the tumor tissue to the rising tissue oxygen level.
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Affiliation(s)
- Tevfik Fikret Cermik
- Department of Nuclear Medicine, School of Medicine, Trakya University, Edirne 22030, Turkey
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Fishman AP. Acute hypoxia and pulmonary vasoconstriction in humans: uncovering the mechanism of the pressor response. Am J Physiol Lung Cell Mol Physiol 2004; 287:L893-4. [PMID: 15475491 DOI: 10.1152/classicessays.00004.2004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This essay looks at the historical significance of an APS classic paper that is freely available online: Motley HL, Cournand A, Werko L, Himmelstein A, and Dresdale D. The influence of short periods of induced acute anoxia upon pulmonary artery pressures in man. Am J Physiol 150: 315–320, 1947 ( http://ajplegacy.physiology.org/cgi/reprint/150/2/315 ).
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Nagaoka T, Morio Y, Casanova N, Bauer N, Gebb S, McMurtry I, Oka M. Rho/Rho kinase signaling mediates increased basal pulmonary vascular tone in chronically hypoxic rats. Am J Physiol Lung Cell Mol Physiol 2004; 287:L665-72. [PMID: 12959926 DOI: 10.1152/ajplung.00050.2003] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recent evidence suggests that Rho/Rho kinase signaling plays an important role in the sustained vasoconstriction induced by many agonists and is involved in the pathogenesis of systemic vascular diseases. However, little is known about its role in increased vascular tone in hypoxic pulmonary hypertension (PH). The purpose of this study was to examine whether Rho/Rho kinase-mediated Ca2+ sensitization contributed to sustained vasoconstriction and increased vasoreactivity in hypoxic PH in rats. Acute intravenous administration of Y-27632, a Rho kinase inhibitor, nearly normalized the high pulmonary arterial blood pressure and total pulmonary resistance in chronically hypoxic rats. In contrast to nifedipine, Y-27632 also markedly decreased elevated basal vascular tone in hypertensive blood-perfused lungs and isolated pulmonary arteries. Y-27632 and another Rho kinase inhibitor, HA-1077, completely reversed nitro-L-arginine-induced vasoconstriction in physiological salt solution-perfused hypertensive lungs, whereas inhibitors of myosin light chain kinase (ML-9), protein kinase C (GF-109203X), phosphatidylinositol 3-kinase (LY-294002), and tyrosine kinase (tyrphostin A23) caused only partial or no reversal of the vasoconstriction. Vasoconstrictor responses to KCl were augmented in hypertensive physiological salt solution-perfused lungs and pulmonary arteries, and the augmentation was eliminated by Y-27632. These results suggest that Rho/Rho kinase-mediated Ca2+ sensitization plays a central role in mediating sustained vasoconstriction and increased vasoreactivity in hypoxic PH.
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Affiliation(s)
- Tetsutaro Nagaoka
- Cardiovascular Pulmonary Research Laboratory, Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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Mateev S, Sillau AH, Mouser R, McCullough RE, White MM, Young DA, Moore LG. Chronic hypoxia opposes pregnancy-induced increase in uterine artery vasodilator response to flow. Am J Physiol Heart Circ Physiol 2003; 284:H820-9. [PMID: 12433660 DOI: 10.1152/ajpheart.00701.2002] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypotheses that pregnancy increases the uterine artery (UA) vasodilator response to flow and that this increase is impaired under conditions of chronic hypoxia (30 days, simulated elevation 3,960 m). UA were isolated from 24 normoxic or chronically hypoxic midpregnant guinea pigs and studied with the use of pressure myography. Normoxic pregnancy increased UA flow vasodilator response and protected against a rise in wall shear stress (WSS). Chronic hypoxia opposed these effects, prompting vasoconstriction at high flow and increasing WSS above levels seen in normoxic pregnant UA. The nitric oxide synthase inhibitor N(G)-nitro-l-arginine (l-NNA) eliminated the pregnancy-associated increase in flow vasodilation in normoxic UA, suggesting that increased nitric oxide production was responsible. The considerable residual vasodilation after nitric oxide synthase and cyclooxygenase inhibition implicated endothelial-derived hyperpolarizing factor (EDHF) as an additional contributor to flow vasodilation. l-NNA increased flow vasodilation in UA from chronically hypoxic animals, suggesting that chronic hypoxia may have lowered EDHF or elevated peroxynitrite production. In conclusion, flow is an important physiological vasodilator for the acute and more chronic UA dimensional changes required to increase uteroplacental blood flow during normal pregnancy. Chronic hypoxia may be a mechanism that opposes the pregnancy-associated rise in UA flow vasodilation, thereby increasing the incidence of preeclampsia and intrauterine growth restriction at a high altitude.
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Affiliation(s)
- Stephanie Mateev
- Women's Health Research Center and Cardiovascular Pulmonary Research Laboratory, University of Colorado Health Sciences Center, Denver 80262, USA
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