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Gebauer PH, Turzo M, Lasitschka F, Weigand MA, Busch CJ. Inhibition of ornithine decarboxylase restores hypoxic pulmonary vasoconstriction in endotoxemic mice. Pulm Circ 2020; 10:2045894020915831. [PMID: 33403098 PMCID: PMC7745575 DOI: 10.1177/2045894020915831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/06/2020] [Indexed: 11/29/2022] Open
Abstract
Endotoxemia impairs hypoxic pulmonary vasoconstriction which leads to systemic hypoxemia. This derogation is attributable to increased activity of nitric oxide synthase 2 and arginase metabolism. Gene expression analysis has shown increased expression of ornithine decarboxylase in lungs of endotoxemic mice, a downstream enzyme of arginase metabolism. The aim of this study was to investigate whether inhibition of ornithine decarboxylase increases hypoxic pulmonary vasoconstriction in lungs of endotoxemic mice. Mice received lipopolysaccharides or saline intraperitoneal, and hypoxic pulmonary vasoconstriction was measured using an isolated perfused mouse lung model. Additional mice with and without endotoxemia were pretreated with the ornithine decarboxylase-inhibitor difluoromethylornithine before examination of hypoxic pulmonary vasoconstriction. Hypoxic pulmonary vasoconstriction was defined as the difference of pulmonary arterial pressure between normoxic and hypoxic ventilation. In addition, lung tissue was analyzed using real-time quantitative polymerase chain reaction, Western blot and immunohistochemistry. Lipopolysaccharides caused an up-regulation of ornithine decarboxylase mRNA level (2.73 ± 0.19-fold increase, p < 0.05) as well as ornithine decarboxylase protein level (4.05 ± 0.37-fold increase, p < 0.05). Endotoxemia attenuated hypoxic pulmonary vasoconstriction when compared with untreated control mice (26.3 ± 9.7% vs. 67.0 ± 17.5%). Difluoromethylornithine (20, 100, 500 mg kg−1 body weight intraperitoneal) restored hypoxic pulmonary vasoconstriction in lungs of endotoxemic mice in a dose-dependent way (25.8 ± 9.9%, 57.3 ± 17.2%, 62.3 ± 12.4%) and decreased hypoxic pulmonary vasoconstriction in control mice (53.6 ± 13.6%, 40.0 ± 14.9%, 35.9 ± 12.4%). These results show that endotoxemia induces ornithine decarboxylase expression and suggest that ornithine decarboxylase contributes to the endotoxemia-induced impairment of hypoxic pulmonary vasoconstriction. Inhibition of ornithine decarboxylase might be a target in the therapy of diseases with inflammation impaired hypoxic pulmonary vasoconstriction, like the sepsis-associated acute respiratory distress syndrome (ARDS).
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Affiliation(s)
- P H Gebauer
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - M Turzo
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - F Lasitschka
- Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany
| | - M A Weigand
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - C J Busch
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
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2
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Turzo M, Spöhr FA, Felix L, Weigand MA, Busch CJ. Kv7 channel inhibition increases hypoxic pulmonary vasoconstriction in endotoxemic mouse lungs. Exp Lung Res 2020; 46:363-375. [PMID: 32945215 DOI: 10.1080/01902148.2020.1818888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Hypoxic pulmonary vasoconstriction (HPV) regulates regional pulmonary blood flow in order to match regional ventilation to preserve arterial oxygenation. HPV is impaired in patients with sepsis or acute respiratory distress syndrome (ARDS). Endotoxemic mice show reduced HPV and recent evidence suggests a central role of voltage gated potassium channel 7 (Kv7) in regulating HPV. Therefore, we tested the hypothesis if Kv7 is induced and inhibition of Kv7 increases HPV in endotoxemia. MATERIALS AND METHODS Isolated lungs of LPS-pretreated and untreated animals were perfused with and without specific inhibitors of Kv7 (linopirdine (LI) 0, 0.1, 1 and 10 µM) or Kv7.1 (HMR1556 100 nM). Pulmonary artery pressure (PAP) during normoxic (FiO2 0.21) as well as hypoxic (FiO2 0.01) ventilation were obtained. Expressions of Kv7 composing (KCNQ1-5) as well as auxiliary subunits (KCNE1-5) were measured in mouse lungs with and without endotoxemia. RESULTS HPV was impaired in lungs from LPS mice (16 ± 7% vs 105 ± 13% control, p < 0.05). Perfusion of control lungs with 10 µM LI or 100 nM HMR1556 did not affect HPV (LI 105 ± 12% vs 105 ± 13% vehicle, HMR1556 100 ± 6% vs 98 ± 26%, P = NS). In LPS mice perfusion with 10 µM LI (74.2 ± 7% vs. 16 ± 7% vehicle, P < 0.05) or HMR1556 100 nM augmented HPV (74 ± 28% vs. 15 ± 17% vehicle, P < 0.05). KCNQ1, 4 and 5 gene- and protein expressions as well as KCNE1, 2 and 4 gene expressions were unaltered in endotoxemic lungs. KCNE3 gene and protein expressions were increased in lungs of LPS treated mice (3.1 ± 1.3-fold and 1.8 ± 0.3-fold, respectively, P < 0.05 for both). CONCLUSIONS Endotoxemia does not alter KCNQ1, 4 and 5 gene and protein expressions but increases pulmonary KCNE3 gene and protein expression. In isolated perfused endotoxemic mouse lungs, perfusion with 10 µM LI or 100 nM HMR1556 augments HPV.
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Affiliation(s)
- Maurizio Turzo
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Fabian A Spöhr
- Department of Anesthesiology, Sana Kliniken, Stuttgart, Germany.,Department of Anesthesiology and Intensive Care Medicine, University of Cologne, Cologne, Germany
| | - Lasitschka Felix
- Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus A Weigand
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Cornelius J Busch
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
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3
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Strielkov I, Krause NC, Knoepp F, Alebrahimdehkordi N, Pak O, Garcia C, Ghofrani HA, Schermuly RT, Seeger W, Grimminger F, Sommer N, Weissmann N. Cytochrome P450 epoxygenase-derived 5,6-epoxyeicosatrienoic acid relaxes pulmonary arteries in normoxia but promotes sustained pulmonary vasoconstriction in hypoxia. Acta Physiol (Oxf) 2020; 230:e13521. [PMID: 32506676 DOI: 10.1111/apha.13521] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 04/27/2020] [Accepted: 05/28/2020] [Indexed: 12/30/2022]
Abstract
AIMS The aim of the study was to investigate the role of cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) in sustained hypoxic pulmonary vasoconstriction (HPV). METHODS Vasomotor responses of isolated mouse intrapulmonary arteries (IPAs) were assessed using wire myography. Key findings were verified by haemodynamic measurements in isolated perfused and ventilated mouse lungs. RESULTS Pharmacological inhibition of EET synthesis with MS-PPOH, application of the EET antagonist 14,15-EEZE or deficiency of CYP2J isoforms suppressed sustained HPV. In contrast, knockdown of EET-degrading soluble epoxide hydrolase or its inhibition with TPPU augmented sustained HPV almost twofold. All EET regioisomers elicited relaxation in IPAs pre-contracted with thromboxane mimetic U46619. However, in the presence of KCl-induced depolarization, 5,6-EET caused biphasic contraction in IPAs and elevation of pulmonary vascular tone in isolated lungs, whereas other regioisomers had no effect. In patch-clamp experiments, hypoxia elicited depolarization in pulmonary artery smooth muscle cells (PASMCs), and 5,6-EET evoked inward whole cell currents in PASMCs depolarized to the hypoxic level, but not at their resting membrane potential. CONCLUSIONS The EET pathway substantially contributes to sustained HPV in mouse pulmonary arteries. 5,6-EET specifically appears to be involved in HPV, as it is the only EET regioisomer able to elicit not only relaxation, but also sustained contraction in these vessels. 5,6-EET-induced pulmonary vasoconstriction is enabled by PASMC depolarization, which occurs in hypoxia. The discovery of the dual role of 5,6-EET in the regulation of pulmonary vascular tone may provide a basis for the development of novel therapeutic strategies for treatment of HPV-related diseases.
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Affiliation(s)
- Ievgen Strielkov
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Nicole C. Krause
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Fenja Knoepp
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Nasim Alebrahimdehkordi
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Oleg Pak
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Claudia Garcia
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Hossein A. Ghofrani
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Ralph T. Schermuly
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Werner Seeger
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Friedrich Grimminger
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Natascha Sommer
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
| | - Norbert Weissmann
- Cardiopulmonary Institute (CPI) German Center for Lung Research (DZL) Justus Liebig University Giessen Giessen Germany
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Kandhi S, Alruwaili N, Wolin MS, Sun D, Huang A. Reciprocal actions of constrictor prostanoids and superoxide in chronic hypoxia-induced pulmonary hypertension: roles of EETs. Pulm Circ 2019; 9:2045894019895947. [PMID: 31908769 DOI: 10.1177/2045894019895947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 11/25/2019] [Indexed: 12/11/2022] Open
Abstract
Epoxyeicosatrienoic acids (EETs) are synthesized from arachidonic acid by CYP/epoxygenase and metabolized by soluble epoxide hydrolase (sEH). Roles of EETs in hypoxia-induced pulmonary hypertension (HPH) remain elusive. The present study aimed to investigate the underlying mechanisms, by which EETs potentiate HPH. Experiments were conducted on sEH knockout (sEH-KO) and wild type (WT) mice after exposure to hypoxia (10% oxygen) for three weeks. In normal/normoxic conditions, WT and sEH-KO mice exhibited comparable pulmonary artery acceleration time (PAAT), ejection time (ET), PAAT/ET ratio, and velocity time integral (VTI), along with similar right ventricular systolic pressure (RVSP). Chronic hypoxia significantly reduced PAAT, ET, and VTI, coincided with an increase in RVSP; these impairments were more severe in sEH-KO than WT mice. Hypoxia elicited downregulation of sEH and upregulation of CYP2C9 accompanied with elevation of CYP-sourced superoxide, leading to enhanced pulmonary EETs in hypoxic mice with significantly higher levels in sEH-KO mice. Isometric tension of isolated pulmonary arteries was recorded. In addition to downregulation of eNOS-induced impairment of vasorelaxation to ACh, HPH mice displayed upregulation of thromboxane A2 (TXA2) receptor, paralleled with enhanced pulmonary vasocontraction to a TXA2 analog (U46619) in an sEH-KO predominant manner. Inhibition of COX-1 or COX-2 significantly prevented the enhancement by ∼50% in both groups of vessels, and the remaining incremental components were eliminated by scavenging of superoxide with Tiron. In conclusion, hypoxia-driven increases in EETs, intensified COXs/TXA2 signaling, great superoxide sourced from activated CYP2C9, and impaired NO bioavailability work in concert, to potentiate HPH development.
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Affiliation(s)
- Sharath Kandhi
- Departments of Physiology, New York Medical College, Valhalla, NY, USA
| | - Norah Alruwaili
- Departments of Physiology, New York Medical College, Valhalla, NY, USA
| | - Michael S Wolin
- Departments of Physiology, New York Medical College, Valhalla, NY, USA
| | - Dong Sun
- Departments of Physiology, New York Medical College, Valhalla, NY, USA
| | - An Huang
- Departments of Physiology, New York Medical College, Valhalla, NY, USA
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5
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Schleifer G, Marutani E, Ferrari M, Sharma R, Skinner O, Goldberger O, Grange RMH, Peneyra K, Malhotra R, Wepler M, Ichinose F, Bloch DB, Mootha VK, Zapol WM. Impaired hypoxic pulmonary vasoconstriction in a mouse model of Leigh syndrome. Am J Physiol Lung Cell Mol Physiol 2018; 316:L391-L399. [PMID: 30520688 PMCID: PMC6397345 DOI: 10.1152/ajplung.00419.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a physiological vasomotor response that maintains systemic oxygenation by matching perfusion to ventilation during alveolar hypoxia. Although mitochondria appear to play an essential role in HPV, the impact of mitochondrial dysfunction on HPV remains incompletely defined. Mice lacking the mitochondrial complex I (CI) subunit Ndufs4 ( Ndufs4-/-) develop a fatal progressive encephalopathy and serve as a model for Leigh syndrome, the most common mitochondrial disease in children. Breathing normobaric 11% O2 prevents neurological disease and improves survival in Ndufs4-/- mice. In this study, we found that either genetic Ndufs4 deficiency or pharmacological inhibition of CI using piericidin A impaired the ability of left mainstem bronchus occlusion (LMBO) to induce HPV. In mice breathing air, the partial pressure of arterial oxygen during LMBO was lower in Ndufs4-/- and in piericidin A-treated Ndufs4+/+ mice than in respective controls. Impairment of HPV in Ndufs4-/- mice was not a result of nonspecific dysfunction of the pulmonary vascular contractile apparatus or pulmonary inflammation. In Ndufs4-deficient mice, 3 wk of breathing 11% O2 restored HPV in response to LMBO. When compared with Ndufs4-/- mice breathing air, chronic hypoxia improved systemic oxygenation during LMBO. The results of this study show that, when breathing air, mice with a congenital Ndufs4 deficiency or chemically inhibited CI function have impaired HPV. Our study raises the possibility that patients with inborn errors of mitochondrial function may also have defects in HPV.
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Affiliation(s)
- Grigorij Schleifer
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Eizo Marutani
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Michele Ferrari
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Rohit Sharma
- Howard Hughes Medical Institute and Department of Molecular Biology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Owen Skinner
- Howard Hughes Medical Institute and Department of Molecular Biology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Olga Goldberger
- Howard Hughes Medical Institute and Department of Molecular Biology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Robert Matthew Henry Grange
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Kathryn Peneyra
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Rajeev Malhotra
- Cardiology Division and Cardiovascular Research Center, Department of Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Martin Wepler
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts.,Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung , Ulm , Germany
| | - Fumito Ichinose
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Donald B Bloch
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts.,Division of Rheumatology, Allergy and Immunology, Department of Medicine, Harvard Medical School and Massachusetts General Hospital , Boston, Massachusetts
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Warren M Zapol
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
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6
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Turzo M, Vaith J, Lasitschka F, Weigand MA, Busch CJ. Role of ATP-sensitive potassium channels on hypoxic pulmonary vasoconstriction in endotoxemia. Respir Res 2018; 19:29. [PMID: 29433570 PMCID: PMC5810061 DOI: 10.1186/s12931-018-0735-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 02/05/2018] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND ATP-regulated potassium channels (KATP) regulate pulmonary vascular tone and are involved in hypoxic pulmonary vasoconstriction (HPV). In patients with inflammation like sepsis or ARDS, HPV is impaired, resulting in a ventilation-perfusion mismatch and hypoxia. Since increase of vascular KATP channel Kir6.1 has been reported in animal models of endotoxemia, we studied the expression and physiological effects of Kir6.1 in murine endotoxemic lungs. We hypothesized that inhibition of overexpressed Kir6.1 increases HPV in endotoxemia. METHODS Mice (C57BL/6; n = 55) with (n = 27) and without (n = 28) endotoxemia (35 mg/kg LPS i.p. for 18 h) were analyzed for Kir6.1 gene as well as protein expression and HPV was examined in isolated perfused mouse lungs with and without selective inhibition of Kir6.1 with PNU-37883A. Pulmonary artery pressure (PAP) and pressure-flow curves during normoxic (FiO2 0.21) and hypoxic (FiO2 0.01) ventilation were obtained. HPV was quantified as the increase in perfusion pressure in response to hypoxic ventilation in mmHg of baseline perfusion pressure (ΔPAP) in the presence and absence of PNU-37883A. RESULTS Endotoxemia increases pulmonary Kir6.1 gene (+ 2.8 ± 0.3-fold) and protein expression (+ 2.1 ± 0.3-fold). Hypoxia increases HPV in lungs of control animals, while endotoxemia decreases HPV (∆PAP control: 9.2 ± 0.9 mmHg vs. LPS: 3.0 ± 0.7 mmHg, p < 0.05, means ± SEM). Inhibition of Kir6.1 with 1 μM PNU-37883A increases HPV in endotoxemia, while not increasing HPV in controls (∆PAP PNU control: 9.3 ± 0.7 mmHg vs. PNU LPS 8.3 ± 0.9 mmHg, p < 0.05, means ± SEM). CONCLUSION Endotoxemia increases pulmonary Kir6.1 gene and protein expression. Inhibition of Kir6.1 augments HPV in murine endotoxemic lungs.
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Affiliation(s)
- Maurizio Turzo
- Department of Anesthesiology, Heidelberg University Hospital, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany
| | - Julian Vaith
- Department of Anesthesiology, Heidelberg University Hospital, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany
| | - Felix Lasitschka
- Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus A Weigand
- Department of Anesthesiology, Heidelberg University Hospital, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany
| | - Cornelius J Busch
- Department of Anesthesiology, Heidelberg University Hospital, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
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7
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Abstract
Hypoxic pulmonary vasoconstriction (HPV) in combination with hypercapnic pulmonary vasoconstriction redistributes pulmonary blood flow from poorly aerated to better ventilated lung regions by an active process of local vasoconstriction. Impairment of HPV results in ventilation-perfusion mismatch and is commonly associated with various lung diseases including pneumonia, sepsis, or cystic fibrosis. Although several regulatory pathways have been identified, considerable knowledge gaps persist, and a unifying concept of the signaling pathways that underlie HPV and their impairment in lung diseases has not yet emerged. In the past, conceptual models of HPV have focused on pulmonary arterial smooth muscle cells (PASMC) acting as sensor and effector of hypoxia in the pulmonary vasculature. In contrast, the endothelium was considered a modulating bystander in this scenario. For an ideal design, however, the oxygen sensor in HPV should be located in the region of gas exchange, i.e., in the alveolar capillary network. This concept requires the retrograde propagation of the hypoxic signal along the endothelial layer of the vascular wall and subsequent contraction of PASMC in upstream arterioles that is elicited via temporospatially tightly controlled endothelial-smooth muscle cell crosstalk. The present review summarizes recent work that provides proof-of-principle for the existence and functional relevance of such signaling pathway in HPV that involves important roles for connexin 40, epoxyeicosatrienoic acids, sphingolipids, and cystic fibrosis transmembrane conductance regulator. Of translational relevance, implication of these molecules provides for novel mechanistic explanations for impaired ventilation/perfusion matching in patients with pneumonia, sepsis, cystic fibrosis, and presumably various other lung diseases.
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Affiliation(s)
- Benjamin Grimmer
- Institute of Physiology, Charité Universitätsmedizin Berlin, Berlin , Germany
| | - Wolfgang M Kuebler
- Institute of Physiology, Charité Universitätsmedizin Berlin, Berlin , Germany
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital , Toronto, Ontario , Canada
- Departments of Surgery and Physiology, University of Toronto , Toronto, Ontario , Canada
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8
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Strielkov I, Pak O, Sommer N, Weissmann N. Recent advances in oxygen sensing and signal transduction in hypoxic pulmonary vasoconstriction. J Appl Physiol (1985) 2017; 123:1647-1656. [PMID: 28751366 DOI: 10.1152/japplphysiol.00103.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a physiological reaction, which adapts lung perfusion to regional ventilation and optimizes gas exchange. Impaired HPV may cause systemic hypoxemia, while generalized HPV contributes to the development of pulmonary hypertension. The triggering mechanisms underlying HPV are still not fully elucidated. Several hypotheses are currently under debate, including a possible decrease as well as an increase in reactive oxygen species as a triggering event. Recent findings suggest an increase in the production of reactive oxygen species in pulmonary artery smooth muscle cells by complex III of the mitochondrial electron transport chain and occurrence of oxygen sensing at complex IV. Other essential components are voltage-dependent potassium and possibly L-type, transient receptor potential channel 6, and transient receptor potential vanilloid 4 channels. The release of arachidonic acid metabolites appears also to be involved in HPV regulation. Further investigation of the HPV mechanisms will facilitate the development of novel therapeutic strategies for the treatment of HPV-related disorders.
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Affiliation(s)
- Ievgen Strielkov
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Oleg Pak
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Natasha Sommer
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
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9
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Wepler M, Beloiartsev A, Buswell MD, Panigrahy D, Malhotra R, Buys ES, Radermacher P, Ichinose F, Bloch DB, Zapol WM. Soluble epoxide hydrolase deficiency or inhibition enhances murine hypoxic pulmonary vasoconstriction after lipopolysaccharide challenge. Am J Physiol Lung Cell Mol Physiol 2016; 311:L1213-L1221. [PMID: 27815261 DOI: 10.1152/ajplung.00394.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/28/2016] [Indexed: 02/08/2023] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is the response of the pulmonary vasculature to low levels of alveolar oxygen. HPV improves systemic arterial oxygenation by matching pulmonary perfusion to ventilation during alveolar hypoxia and is impaired in lung diseases such as the acute respiratory distress syndrome (ARDS) and in experimental models of endotoxemia. Epoxyeicosatrienoic acids (EETs) are pulmonary vasoconstrictors, which are metabolized to less vasoactive dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase (sEH). We hypothesized that pharmacological inhibition or a congenital deficiency of sEH in mice would reduce the metabolism of EETs and enhance HPV in mice after challenge with lipopolysaccharide (LPS). HPV was assessed 22 h after intravenous injection of LPS by measuring the percentage increase in the pulmonary vascular resistance of the left lung induced by left mainstem bronchial occlusion (LMBO). After LPS challenge, HPV was impaired in sEH+/+, but not in sEH-/- mice or in sEH+/+ mice treated acutely with a sEH inhibitor. Deficiency or pharmacological inhibition of sEH protected mice from the LPS-induced decrease in systemic arterial oxygen concentration (PaO2 ) during LMBO. In the lungs of sEH-/- mice, the LPS-induced increase in DHETs and cytokines was attenuated. Deficiency or pharmacological inhibition of sEH protects mice from LPS-induced impairment of HPV and improves the PaO2 after LMBO. After LPS challenge, lung EET degradation and cytokine expression were reduced in sEH-/- mice. Inhibition of sEH might prove to be an effective treatment for ventilation-perfusion mismatch in lung diseases such as ARDS.
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Affiliation(s)
- Martin Wepler
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Arkadi Beloiartsev
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Mary D Buswell
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Dipak Panigrahy
- Harvard Medical School, Boston, Massachusetts.,Center for Vascular Biology Research and Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Rajeev Malhotra
- Harvard Medical School, Boston, Massachusetts.,Cardiology Division and Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Emmanuel S Buys
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Peter Radermacher
- Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Universitätsklinik Ulm, Ulm, Germany
| | - Fumito Ichinose
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Donald B Bloch
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts.,Division of Rheumatology, Allergy and Immunology, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Warren M Zapol
- Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts; .,Harvard Medical School, Boston, Massachusetts
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10
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Zhu L, Maruvada R, Sapirstein A, Peters-Golden M, Kim KS. Cysteinyl leukotrienes as novel host factors facilitating Cryptococcus neoformans penetration into the brain. Cell Microbiol 2016; 19. [PMID: 27573789 DOI: 10.1111/cmi.12661] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/27/2016] [Accepted: 08/05/2016] [Indexed: 01/07/2023]
Abstract
Cryptococcus neoformas infection of the central nervous system (CNS) continues to be an important cause of mortality and morbidity, and a major contributing factor is our incomplete knowledge of the pathogenesis of this disease. Here, we provide the first direct evidence that C. neoformans exploits host cysteinyl leukotrienes (LTs), formed via LT biosynthetic pathways involving cytosolic phospholipase A2 α (cPLA2 α) and 5-lipoxygenase (5-LO) and acting via cysteinyl leukotriene type 1 receptor (CysLT1), for penetration of the blood-brain barrier. Gene deletion of cPLA2 α and 5-LO and pharmacological inhibition of cPLA2 α, 5-LO and CysLT1 were effective in preventing C. neoformans penetration of the blood-brain barrier in vitro and in vivo. A CysLT1 antagonist enhanced the efficacy of an anti-fungal agent in therapy of C. neoformans CNS infection in mice. These findings demonstrate that host cysteinyl LTs, dependent on the actions of cPLA2 α and 5-LO, promote C. neoformans penetration of the blood-brain barrier and represent novel targets for elucidating the pathogenesis and therapeutic development of C. neoformans CNS infection.
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Affiliation(s)
- Longkun Zhu
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Cell Biology and Medical Genetics/Center for Cell and Developmental Biology, School of Basic Medical Sciences Fujian Medical University, Fuzhou, Fujian, China
| | - Ravi Maruvada
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Adam Sapirstein
- Department of Anesthesiology and Critical Care Medicine, Baltimore, MD, USA
| | - Marc Peters-Golden
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Kwang Sik Kim
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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11
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Yoo HY, Park SJ, Kim HJ, Kim WK, Kim SJ. Integrative understanding of hypoxic pulmonary vasoconstriction using in vitro models: from ventilated/perfused lung to single arterial myocyte. Integr Med Res 2014; 3:180-188. [PMID: 28664095 PMCID: PMC5481745 DOI: 10.1016/j.imr.2014.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/27/2014] [Accepted: 08/27/2014] [Indexed: 10/25/2022] Open
Abstract
Contractile response of a pulmonary artery (PA) to hypoxia (hypoxic pulmonary vasoconstriction; HPV) is a unique physiological reaction. HPV is beneficial for the optimal distribution of blood flow to differentially ventilated alveolar regions in the lung, thereby preventing systemic hypoxemia. Numerous in vitro studies have been conducted to elucidate the mechanisms underlying HPV. These studies indicate that PA smooth muscle cells (PASMCs) sense lowers the oxygen partial pressure (PO2) and contract under hypoxia. As for the PO2-sensing molecules, a variety of ion channels in PASMCs had been suggested. Nonetheless, the modulator(s) of the ion channels alone cannot mimic HPV in the experiments using PA segments and/or isolated organs. We compared the hypoxic responses of PASMCs, PAs, lung slices, and total lungs using a variety of methods (e.g., patch-clamp technique, isometric contraction measurement, video analysis of precision-cut lung slices, and PA pressure measurement in ventilated/perfused lungs). In this review, the relevant results are compared to provide a comprehensive understanding of HPV. Integration of the influences from surrounding tissues including blood cells as well as the hypoxic regulation of ion channels in PASMCs are indispensable for insights into HPV and other related clinical conditions.
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Affiliation(s)
- Hae Young Yoo
- Red Cross College of Nursing, Chung-Ang University, Seoul, Korea
| | - Su Jung Park
- Department of Physiology, College of Medicine, Seoul National University, Seoul, Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Korea.,Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul, Korea
| | - Hae Jin Kim
- Department of Physiology, College of Medicine, Seoul National University, Seoul, Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Korea.,Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul, Korea
| | - Woo Kyung Kim
- Department of Internal Medicine and Channelopathy Research Institute (CRC), College of Medicine, Dongguk University, Goyang, Korea
| | - Sung Joon Kim
- Department of Physiology, College of Medicine, Seoul National University, Seoul, Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Korea.,Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul, Korea
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12
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Dong K, Yao N, Pu Y, He X, Zhao Q, Luan Y, Guan W, Rao S, Ma Y. Genomic scan reveals loci under altitude adaptation in Tibetan and Dahe pigs. PLoS One 2014; 9:e110520. [PMID: 25329542 PMCID: PMC4201535 DOI: 10.1371/journal.pone.0110520] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 09/16/2014] [Indexed: 01/04/2023] Open
Abstract
High altitude environments are of particular interest in the studies of local adaptation as well as their implications in physiology and clinical medicine in human. Some Chinese pig breeds, such as Tibetan pig (TBP) that is well adapted to the high altitude and Dahe pig (DHP) that dwells at the moderate altitude, provide ideal materials to study local adaptation to altitudes. Yet, it is still short of in-depth analysis and understanding of the genetic adaptation to high altitude in the two pig populations. In this study we conducted a genomic scan for selective sweeps using FST to identify genes showing evidence of local adaptations in TBP and DHP, with Wuzhishan pig (WZSP) as the low-altitude reference. Totally, we identified 12 specific selective genes (CCBE1, F2RL1, AGGF1, ZFPM2, IL2, FGF5, PLA2G4A, ADAMTS9, NRBF2, JMJD1C, VEGFC and ADAM19) for TBP and six (OGG1, FOXM, FLT3, RTEL1, CRELD1 and RHOG) for DHP. In addition, six selective genes (VPS13A, GNA14, GDAP1, PARP8, FGF10 and ADAMTS16) were shared by the two pig breeds. Among these selective genes, three (VEGFC, FGF10 and ADAMTS9) were previously reported to be linked to the local adaptation to high altitudes in pigs, while many others were newly identified by this study. Further bioinformatics analysis demonstrated that majority of these selective signatures have some biological functions relevant to the altitude adaptation, for examples, response to hypoxia, development of blood vessels, DNA repair and several hematological involvements. These results suggest that the local adaptation to high altitude environments is sophisticated, involving numerous genes and multiple biological processes, and the shared selective signatures by the two pig breeds may provide an effective avenue to identify the common adaptive mechanisms to different altitudes.
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Affiliation(s)
- Kunzhe Dong
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Na Yao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yabin Pu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaohong He
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qianjun Zhao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yizhao Luan
- Institute for Medical Systems Biology and Department of Medical Statistics and Epidemiology, Guangdong Medical College, Dongguan, China
| | - Weijun Guan
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shaoqi Rao
- Institute for Medical Systems Biology and Department of Medical Statistics and Epidemiology, Guangdong Medical College, Dongguan, China
- * E-mail: (YHM); (SQR)
| | - Yuehui Ma
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail: (YHM); (SQR)
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13
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Deletion of the murine cytochrome P450 Cyp2j locus by fused BAC-mediated recombination identifies a role for Cyp2j in the pulmonary vascular response to hypoxia. PLoS Genet 2013; 9:e1003950. [PMID: 24278032 PMCID: PMC3836722 DOI: 10.1371/journal.pgen.1003950] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 09/27/2013] [Indexed: 01/10/2023] Open
Abstract
Epoxyeicosatrienoic acids (EETs) confer vasoactive and cardioprotective functions. Genetic analysis of the contributions of these short-lived mediators to pathophysiology has been confounded to date by the allelic expansion in rodents of the portion of the genome syntenic to human CYP2J2, a gene encoding one of the principle cytochrome P450 epoxygenases responsible for the formation of EETs in humans. Mice have eight potentially functional genes that could direct the synthesis of epoxygenases with properties similar to those of CYP2J2. As an initial step towards understanding the role of the murine Cyp2j locus, we have created mice bearing a 626-kb deletion spanning the entire region syntenic to CYP2J2, using a combination of homologous and site-directed recombination strategies. A mouse strain in which the locus deletion was complemented by transgenic delivery of BAC sequences encoding human CYP2J2 was also created. Systemic and pulmonary hemodynamic measurements did not differ in wild-type, null, and complemented mice at baseline. However, hypoxic pulmonary vasoconstriction (HPV) during left mainstem bronchus occlusion was impaired and associated with reduced systemic oxygenation in null mice, but not in null mice bearing the human transgene. Administration of an epoxygenase inhibitor to wild-type mice also impaired HPV. These findings demonstrate that Cyp2j gene products regulate the pulmonary vascular response to hypoxia. In mice and humans, the CYP2J class of cytochrome P450 epoxygenases metabolizes arachidonic acid (AA) to epoxyeicosatrienoic acids (EETs), short-lived mediators with effects on both the pulmonary and systemic vasculature. Genetic dissection of CYP2J function to date has been complicated by allelic expansion in the rodent genome. In this study, the mouse chromosomal locus syntenic to human CYP2J2, containing eight presumed genes and two pseudogenes, was deleted via generation of a recombinant template created by homologous and site-specific recombination steps that joined two precursor bacterial artificial chromosomes (BACs). The Cyp2j null mice were subsequently complemented by transgenic delivery of BAC sequences encoding human CYP2J2. Hypoxic pulmonary vasoconstriction (HPV) and systemic oxygenation during regional alveolar hypoxia were unexpectedly found to be impaired in null mice, but not in null mice bearing the transgenic human allele, suggesting that Cyp2j products contribute to the pulmonary vascular response to hypoxia.
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14
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Stanke-Labesque F, Pépin JL, Gautier-Veyret E, Lévy P, Bäck M. Leukotrienes as a molecular link between obstructive sleep apnoea and atherosclerosis. Cardiovasc Res 2013; 101:187-93. [DOI: 10.1093/cvr/cvt247] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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15
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Yan G, Wang Q, Shi H, Han Y, Ma G, Tang C, Gu Y. Regulation of rat intrapulmonary arterial tone by arachidonic acid and prostaglandin E2 during hypoxia. PLoS One 2013; 8:e73839. [PMID: 24013220 PMCID: PMC3754945 DOI: 10.1371/journal.pone.0073839] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 07/30/2013] [Indexed: 12/11/2022] Open
Abstract
AIMS Arachidonic acid (AA) and its metabolites, prostaglandins (PG) are known to be involved in regulation of vascular homeostasis including vascular tone and vessel wall tension, but their potential role in Hypoxic pulmonary vasoconstriction (HPV) remains unclear. In this study, we examined the effects of AA and PGE2 on the hypoxic response in isolated rat intrapulmonary arteries (IPAs). METHODS AND RESULTS We carried out the investigation on IPAs by vessel tension measurement. Isotetrandrine (20 µM) significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. Both indomethacin (100 µM) and NS398 attenuated KPSS-induced vessel contraction and phase I, phase IIb and phase IIc of HPV, implying that COX-2 plays a primary role in the hypoxic response of rat IPAs. PGE2 alone caused a significant vasoconstriction in isolated rat IPAs. This constriction is mediated by EP4. Blockage of EP4 by L-161982 (1 µM) significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. However, AH6809 (3 µM), an antagonist of EP1, EP2, EP3 and DP1 receptors, exerted no effect on KPSS or hypoxia induced vessel contraction. Increase of cellular cAMP by forskolin could significantly reduce KPSS-induced vessel contraction and abolish phase I, phase II b and phase II c of HPV. CONCLUSION Our results demonstrated a vasoconstrictive effect of PGE2 on rat IPAs and this effect is via activation of EP4. Furthermore, our results suggest that intracellular cAMP plays dual roles in regulation of vascular tone, depending on the spatial distribution of cAMP and its coupling with EP receptor and Ca(2+) channels.
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Affiliation(s)
- Gaoliang Yan
- Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, China ; Institute of Molecular Medicine, Peking University, Beijing, China
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16
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Ko EA, Wan J, Yamamura A, Zimnicka AM, Yamamura H, Yoo HY, Tang H, Smith KA, Sundivakkam PC, Zeifman A, Ayon RJ, Makino A, Yuan JXJ. Functional characterization of voltage-dependent Ca(2+) channels in mouse pulmonary arterial smooth muscle cells: divergent effect of ROS. Am J Physiol Cell Physiol 2013; 304:C1042-52. [PMID: 23426966 DOI: 10.1152/ajpcell.00304.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Electromechanical coupling via membrane depolarization-mediated activation of voltage-dependent Ca(2+) channels (VDCC) is an important mechanism in regulating pulmonary vascular tone, while mouse is an animal model often used to study pathogenic mechanisms of pulmonary vascular disease. The function of VDCC in mouse pulmonary artery (PA) smooth muscle cells (PASMC), however, has not been characterized, and their functional role in reactive oxygen species (ROS)-mediated regulation of vascular function remains unclear. In this study, we characterized the electrophysiological and pharmacological properties of VDCC in PASMC and the divergent effects of ROS produced by xanthine oxidase (XO) and hypoxanthine (HX) on VDCC in PA and mesenteric artery (MA). Our data show that removal of extracellular Ca(2+) or application of nifedipine, a dihydropyridine VDCC blocker, both significantly inhibited 80 mM K(+)-mediated PA contraction. In freshly dissociated PASMC, the maximum inward Ca(2+) currents were -2.6 ± 0.2 pA/pF at +10 mV (with a holding potential of -70 mV). Window currents were between -40 and +10 mV with a peak at -15.4 mV. Nifedipine inhibited currents with an IC(50) of 0.023 μM, and 1 μM Bay K8644, a dihydropyridine VDCC agonist, increased the inward currents by 61%. XO/HX attenuated 60 mM K(+)-mediated increase in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) due to Ca(2+) influx through VDCC in PASMC. Exposure to XO/HX caused relaxation in PA preconstricted by 80 mM K(+) but not in aorta and MA. In contrast, H(2)O(2) inhibited high K(+)-mediated increase in [Ca(2+)](cyt) and caused relaxation in both PA and MA. Indeed, RT-PCR and Western blot analysis revealed significantly lower expression of Ca(V)1.3 in MA compared with PA. Thus our study characterized the properties of VDCC and demonstrates that ROS differentially regulate vascular contraction by regulating VDCC in PA and systemic arteries.
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Affiliation(s)
- Eun A Ko
- Department of Medicine, Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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17
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Beloiartsev A, Baron DM, Yu B, Bloch KD, Zapol WM. Hemoglobin infusion does not alter murine pulmonary vascular tone. Nitric Oxide 2013; 30:1-8. [PMID: 23313572 DOI: 10.1016/j.niox.2012.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 12/18/2012] [Accepted: 12/28/2012] [Indexed: 12/31/2022]
Abstract
Plasma hemoglobin (Hb) scavenges endothelium-derived nitric oxide (NO), producing systemic and pulmonary vasoconstriction in many species. We hypothesized that i.v. administration of murine cell-free Hb would produce pulmonary vasoconstriction and enhance hypoxic pulmonary vasoconstriction (HPV) in mice. To assess the impact of plasma Hb on basal pulmonary vascular tone in anesthetized mice we measured left lung pulmonary vascular resistance (LPVRI) before and after infusion of Hb at thoracotomy. To confirm the findings obtained at thoracotomy, measurements of right ventricular systolic pressure (RVSP) and systemic arterial pressure (SAP) were obtained in closed-chest wild-type mice. To elucidate whether pretreatment with Hb augments HPV we assessed the increase in LPVRI before and during regional lung hypoxia produced by left mainstem bronchial occlusion (LMBO) in wild-type mice pretreated with Hb. Infusion of Hb increased SAP but did not change pulmonary arterial pressure (PAP), left lung pulmonary arterial flow (QLPA) or LPVRI in either wild-type or diabetic mice with endothelial dysfunction. Scavenging of NO by plasma Hb did not alter HPV in wild-type mice. Inhibition of NO synthase with l-NAME did not change the basal LPVRI, but augmented HPV during LMBO. Our data suggest that scavenging of NO by plasma Hb does not alter pulmonary vascular tone in mice. Therefore, generation of NO in the pulmonary circulation is unlikely to be responsible for the low basal pulmonary vascular tone of mice.
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Affiliation(s)
- Arkadi Beloiartsev
- Postdoctoral Fellow, Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114-2696, USA
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18
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Wang L, Yin J, Nickles HT, Ranke H, Tabuchi A, Hoffmann J, Tabeling C, Barbosa-Sicard E, Chanson M, Kwak BR, Shin HS, Wu S, Isakson BE, Witzenrath M, de Wit C, Fleming I, Kuppe H, Kuebler WM. Hypoxic pulmonary vasoconstriction requires connexin 40-mediated endothelial signal conduction. J Clin Invest 2012; 122:4218-30. [PMID: 23093775 PMCID: PMC3484430 DOI: 10.1172/jci59176] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 08/30/2012] [Indexed: 12/21/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a physiological mechanism by which pulmonary arteries constrict in hypoxic lung areas in order to redirect blood flow to areas with greater oxygen supply. Both oxygen sensing and the contractile response are thought to be intrinsic to pulmonary arterial smooth muscle cells. Here we speculated that the ideal site for oxygen sensing might instead be at the alveolocapillary level, with subsequent retrograde propagation to upstream arterioles via connexin 40 (Cx40) endothelial gap junctions. HPV was largely attenuated by Cx40-specific and nonspecific gap junction uncouplers in the lungs of wild-type mice and in lungs from mice lacking Cx40 (Cx40-/-). In vivo, hypoxemia was more severe in Cx40-/- mice than in wild-type mice. Real-time fluorescence imaging revealed that hypoxia caused endothelial membrane depolarization in alveolar capillaries that propagated to upstream arterioles in wild-type, but not Cx40-/-, mice. Transformation of endothelial depolarization into vasoconstriction involved endothelial voltage-dependent α1G subtype Ca2+ channels, cytosolic phospholipase A2, and epoxyeicosatrienoic acids. Based on these data, we propose that HPV originates at the alveolocapillary level, from which the hypoxic signal is propagated as endothelial membrane depolarization to upstream arterioles in a Cx40-dependent manner.
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MESH Headings
- Animals
- Calcium Channels/metabolism
- Connexins/genetics
- Connexins/metabolism
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- Human Umbilical Vein Endothelial Cells
- Humans
- Hypoxia/genetics
- Hypoxia/metabolism
- Hypoxia/pathology
- Hypoxia/physiopathology
- Lung/blood supply
- Lung/metabolism
- Lung/pathology
- Lung/physiopathology
- Mice
- Mice, Knockout
- Muscle, Smooth/metabolism
- Muscle, Smooth/pathology
- Muscle, Smooth/physiopathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Phospholipases A2, Cytosolic/metabolism
- Pulmonary Artery/metabolism
- Pulmonary Artery/pathology
- Pulmonary Artery/physiopathology
- Signal Transduction
- Vasoconstriction
- Gap Junction alpha-5 Protein
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Affiliation(s)
- Liming Wang
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jun Yin
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hannah T. Nickles
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hannes Ranke
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Arata Tabuchi
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Julia Hoffmann
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Christoph Tabeling
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Eduardo Barbosa-Sicard
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Marc Chanson
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Brenda R. Kwak
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hee-Sup Shin
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Songwei Wu
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Brant E. Isakson
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Martin Witzenrath
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Cor de Wit
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ingrid Fleming
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Hermann Kuppe
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Wolfgang M. Kuebler
- The Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada.
Institute of Physiology, Department of Internal Medicine, Charité-Universitätsmedizin, Berlin, Germany.
Department of Cardiothoracic Surgery, Affiliated People′s Hospital of Jiangsu University, Zhenjiang, China.
German Heart Institute, Berlin, Germany.
Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, Charité-Universitätsmedizin Berlin, Germany.
Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University Frankfurt, Frankfurt, Germany.
Laboratory of Clinical Investigation III, Hôpitaux Universitaires de Genève (HUG), and
Department of Pathology and Immunology, Université de Genève, Genève, Switzerland.
Center for Neural Science, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA.
Robert M. Berne Cardiovascular Research Center, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
Institute of Physiology, University of Lübeck, Lübeck, Germany.
Department of Surgery and Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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19
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Calderon LE, Liu S, Su W, Xie Z, Guo Z, Eberhard W, Gong MC. iPLA2β overexpression in smooth muscle exacerbates angiotensin II-induced hypertension and vascular remodeling. PLoS One 2012; 7:e31850. [PMID: 22363752 PMCID: PMC3282780 DOI: 10.1371/journal.pone.0031850] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 01/13/2012] [Indexed: 12/12/2022] Open
Abstract
Objectives Calcium independent group VIA phospholipase A2 (iPLA2β) is up-regulated in vascular smooth muscle cells in some diseases, but whether the up-regulated iPLA2β affects vascular morphology and blood pressure is unknown. The current study addresses this question by evaluating the basal- and angiotensin II infusion-induced vascular remodeling and hypertension in smooth muscle specific iPLA2β transgenic (iPLA2β -Tg) mice. Method and Results Blood pressure was monitored by radiotelemetry and vascular remodeling was assessed by morphologic analysis. We found that the angiotensin II-induced increase in diastolic pressure was significantly higher in iPLA2β-Tg than iPLA2β-Wt mice, whereas, the basal blood pressure was not significantly different. The media thickness and media∶lumen ratio of the mesenteric arteries were significantly increased in angiotensin II-infused iPLA2β-Tg mice. Analysis revealed no difference in vascular smooth muscle cell proliferation. In contrast, adenovirus-mediated iPLA2β overexpression in cultured vascular smooth muscle cells promoted angiotensin II-induced [3H]-leucine incorporation, indicating enhanced hypertrophy. Moreover, angiotensin II infusion-induced c-Jun phosphorylation in vascular smooth muscle cells overexpressing iPLA2β to higher levels, which was abolished by inhibition of 12/15 lipoxygenase. In addition, we found that angiotensin II up-regulated the endogenous iPLA2β protein in-vitro and in-vivo. Conclusion The present study reports that iPLA2β up-regulation exacerbates angiotensin II-induced vascular smooth muscle cell hypertrophy, vascular remodeling and hypertension via the 12/15 lipoxygenase and c-Jun pathways.
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MESH Headings
- Angiotensin II/administration & dosage
- Angiotensin II/pharmacology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiopathology
- Arachidonate 15-Lipoxygenase
- Arachidonic Acid/metabolism
- Blood Pressure/drug effects
- Cell Proliferation/drug effects
- Diastole/drug effects
- Group VI Phospholipases A2/metabolism
- Hypertension/enzymology
- Hypertension/pathology
- Hypertension/physiopathology
- Hypertrophy
- Leucine/metabolism
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiopathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Organ Specificity/drug effects
- Proto-Oncogene Proteins c-jun/metabolism
- Rats
- Signal Transduction/drug effects
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Lindsay E. Calderon
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Shu Liu
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wen Su
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhongwen Xie
- Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhenheng Guo
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wanda Eberhard
- Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ming C. Gong
- Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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20
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Host cytosolic phospholipase A₂α contributes to group B Streptococcus penetration of the blood-brain barrier. Infect Immun 2011; 79:4088-93. [PMID: 21825068 DOI: 10.1128/iai.05506-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Group B Streptococcus (GBS) is the most common bacterium causing neonatal meningitis, and neonatal GBS meningitis continues to be an important cause of mortality and morbidity. Here we provide the first direct evidence that host cytosolic phospholipase A₂α (cPLA₂α) contributes to type III GBS invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier and penetration into the brain, the key step required for the development of GBS meningitis. This was shown by our demonstration that pharmacological inhibition and gene deletion of cPLA₂α significantly decreased GBS invasion of the HBMEC monolayer and penetration into the brain. cPLA₂α releases arachidonic acid from membrane phospholipids, and we showed that the contribution of cPLA₂α to GBS invasion of HBMEC involved lipoxygenated metabolites of arachidonic acid, cysteinyl leukotrienes (LTs). In addition, type III GBS invasion of the HBMEC monolayer involves protein kinase Cα (PKCα), as shown by time-dependent PKCα activation in response to GBS as well as decreased GBS invasion in HBMEC expressing dominant-negative PKCα. PKCα activation in response to GBS, however, was abolished by inhibition of cPLA₂α and cysteinyl LTs, suggesting that cPLA₂α and cysteinyl LTs contribute to type III GBS invasion of the HBMEC monolayer via PKCα. These findings demonstrate that specific host factors involving cPLA₂α and cysteinyl LTs contribute to type III GBS penetration of the blood-brain barrier and their contribution involves PKCα.
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21
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Tanaka K, Yamamoto Y, Ogino K, Tsujimoto S, Saito M, Uozumi N, Shimizu T, Hisatome I. Cytosolic phospholipase A2alpha contributes to blood pressure increases and endothelial dysfunction under chronic NO inhibition. Arterioscler Thromb Vasc Biol 2011; 31:1133-8. [PMID: 21350197 DOI: 10.1161/atvbaha.110.218370] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Nitric oxide (NO) is an important modulator of cardiovascular function. In this study, we examined whether cytosolic phospholipase A2α (cPLA2α), an initial enzyme in the arachidonic acid pathway, is involved in blood pressure (BP) elevation in a murine model of chronic NO inhibition. METHODS AND RESULTS cPLA2α gene-deficient mice (cPLA2α-/-) and wild-type mice (WT) were administered the NO synthesis inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) for 4 weeks. Before treatment, BP was comparable in both groups; it increased significantly in the WT but not in the cPLA2α-/- after treatment. Bone marrow transplantation experiments showed that cPLA2α in blood cells and plasma eicosanoid concentrations were not involved in BP elevation by L-NAME treatment. Activation of cPLA2α and subsequent production of eicosanoids in the aortic endothelium but not in aortic smooth muscle cell, heart, or kidney was observed after L-NAME treatment. Aortic ring assays revealed that endothelial function was comparable in both groups of mice before treatment. L-NAME treatment disturbed endothelial function in WT but not in cPLA2α-/-. CONCLUSIONS These results suggest that endothelial cPLA2α may play a principal role in L-NAME-induced hypertension and may be a target molecule for maintaining endothelial function under NO inhibition.
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Affiliation(s)
- Kohei Tanaka
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Tottori University Graduate School of Medical Science, and Center for Clinical Residency Program, Tottori University Hospital, 36-1 Nishi-machi, Yonago 683-8504, Japan
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22
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Park SJ, Yoo HY, Earm YE, Kim SJ, Kim JK, Kim SD. Role of arachidonic acid-derived metabolites in the control of pulmonary arterial pressure and hypoxic pulmonary vasoconstriction in rats. Br J Anaesth 2010; 106:31-7. [PMID: 20935003 DOI: 10.1093/bja/aeq268] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The roles of arachidonic acid (AA) metabolites in hypoxia-induced pulmonary vasoconstriction (HPV), a critical physiological mechanism that prevents ventilation/perfusion mismatch, are still incompletely understood. METHODS Pulmonary arterial pressure was measured in ventilated/perfused rat lungs. Isometric tones of rat intralobar pulmonary arteries were also measured, using a myograph. RESULTS Hypoxia (Po₂, 3%)-induced pulmonary arterial pressure increases (ΔPAP(hypox)) were stable with blood-mixed perfusate, but decayed spontaneously. ΔPAP(hypox) was inhibited by 29%, 16%, and 28% by the thromboxane A₂ (TXA₂) antagonist SQ-29548, the 5-lipoxygenase inhibitor, MK886, and the leukotriene D₄ antagonist, LY-171883, respectively. The prostacyclin synthase inhibitor tranylcypromine augmented ΔPAP(hypox) by 5%, whereas inhibition of cytochrome P450 did not affect ΔPAP(hypox). Consistently, the TXA₂ analogue U46619 increased ΔPAP(hypox) whereas prostacyclin abolished ΔPAP(hypox). However, leukotriene D₄ had no direct effect on ΔPAP(hypox). In the isolated pulmonary arteries, pretreatment with U46619 was essential to demonstrate hypoxia-induced contraction. CONCLUSIONS The above results suggest that TXA₂ and cysteinyl leukotrienes, other than leukotriene D₄, are endogenous factors that facilitate HPV in rats. The indispensable role of TXA₂-induced pretone in the HPV of isolated pulmonary arteries indicates that the signal from thromboxane receptors might be a critical component of oxygen sensation mechanisms.
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Affiliation(s)
- S J Park
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
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23
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Zhu L, Maruvada R, Sapirstein A, Malik KU, Peters-Golden M, Kim KS. Arachidonic acid metabolism regulates Escherichia coli penetration of the blood-brain barrier. Infect Immun 2010; 78:4302-10. [PMID: 20696828 PMCID: PMC2950368 DOI: 10.1128/iai.00624-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 07/09/2010] [Accepted: 07/30/2010] [Indexed: 01/29/2023] Open
Abstract
Escherichia coli K1 meningitis occurs following penetration of the blood-brain barrier, but the underlying mechanisms involved in E. coli penetration of the blood-brain barrier remain incompletely understood. We have previously shown that host cytosolic phospholipase A(2)α (cPLA(2)α) contributes to E. coli invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier, but the underlying mechanisms remain unclear. cPLA(2)α selectively liberates arachidonic acid from membrane phospholipids. Here, we provide the first direct evidence that host 5-lipoxygenase and lipoxygenase products of arachidonic acid, cysteinyl leukotrienes (LTs), contribute to E. coli K1 invasion of HBMEC and penetration into the brain, and their contributions involve protein kinase C alpha (PKCα). These findings demonstrate that arachidonic acid metabolism regulates E. coli penetration of the blood-brain barrier, and studies are needed to further elucidate the mechanisms involved with metabolic products of arachidonic acid for their contribution to E. coli invasion of the blood-brain barrier.
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Affiliation(s)
- Longkun Zhu
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Ravi Maruvada
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Adam Sapirstein
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Kafait U. Malik
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Marc Peters-Golden
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
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24
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Fuchs B, Sommer N, Dietrich A, Schermuly RT, Ghofrani HA, Grimminger F, Seeger W, Gudermann T, Weissmann N. Redox signaling and reactive oxygen species in hypoxic pulmonary vasoconstriction. Respir Physiol Neurobiol 2010; 174:282-91. [PMID: 20801235 DOI: 10.1016/j.resp.2010.08.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/20/2010] [Accepted: 08/20/2010] [Indexed: 11/16/2022]
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is an essential physiological mechanism of the lung that matches blood perfusion with alveolar ventilation to optimize gas exchange. Perturbations of HPV, as may occur in pneumonia or adult respiratory distress syndrome, can cause life-threatening hypoxemia. Despite intensive research for decades, the molecular mechanisms of HPV have not been fully elucidated. Reactive oxygen species (ROS) and changes in the cellular redox state are proposed to link O2 sensing and pulmonary arterial smooth muscle cell contraction underlying HPV. In this regard, mitochondria and NAD(P)H oxidases are discussed as sources of ROS. However, there is controversy whether ROS levels decrease or increase during hypoxia. With this background we summarize the current knowledge on the role of ROS and redox state in HPV.
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Affiliation(s)
- Beate Fuchs
- Excellence Cluster Cardio-Pulmonary System, University of Giessen Lung Center, Department of Internal Medicine II, Justus-Liebig-University Giessen, Aulweg 130, 35392 Giessen, Germany
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Keserü B, Barbosa-Sicard E, Popp R, Fisslthaler B, Dietrich A, Gudermann T, Hammock BD, Falck JR, Weissmann N, Busse R, Fleming I. Epoxyeicosatrienoic acids and the soluble epoxide hydrolase are determinants of pulmonary artery pressure and the acute hypoxic pulmonary vasoconstrictor response. FASEB J 2008; 22:4306-15. [PMID: 18725458 DOI: 10.1096/fj.08-112821] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent findings have indicated a role for cytochrome P-450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) in acute hypoxic pulmonary vasoconstriction (HPV). Given that the intracellular concentration of EETs is determined by the soluble epoxide hydrolase (sEH), we assessed the influence of the sEH and 11,12-EET on pulmonary artery pressure and HPV in the isolated mouse lung. In lungs from wild-type mice, HPV was significantly increased by sEH inhibition, an effect abolished by pretreatment with CYP epoxygenase inhibitors and the EET antagonist 14,15-EEZE. HPV and EET production were greater in lungs from sEH(-/-) mice than from wild-type mice and sEH inhibition had no further effect on HPV, while MSPPOH and 14,15-EEZE decreased the response. 11,12-EET increased pulmonary artery pressure in a concentration-dependent manner and enhanced HPV via a Rho-dependent mechanism. Both 11,12-EET and hypoxia elicited the membrane translocation of a transient receptor potential (TRP) C6-V5 fusion protein, the latter effect was sensitive to 14,15-EEZE. Moreover, while acute hypoxia and 11,12-EET increased pulmonary pressure in lungs from TRPC6(+/-) mice, lungs from TRPC6(-/-) mice did not respond to either stimuli. These data demonstrate that CYP-derived EETs are involved in HPV and that EET-induced pulmonary contraction under normoxic and hypoxic conditions involves a TRPC6-dependent pathway.
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Affiliation(s)
- Benjamin Keserü
- Vascular Signalling Group, Institut für Kardiovaskuläre Physiologie, Goethe-Universität Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
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26
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Meng F, To WKL, Gu Y. Inhibition effect of arachidonic acid on hypoxia-induced [Ca(2+)](i) elevation in PC12 cells and human pulmonary artery smooth muscle cells. Respir Physiol Neurobiol 2008; 162:18-23. [PMID: 18455484 DOI: 10.1016/j.resp.2008.03.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 03/13/2008] [Accepted: 03/17/2008] [Indexed: 11/29/2022]
Abstract
[Ca(2+)](i) elevation is a key event when O(2) sensitive cells, e.g. PC12 cells and pulmonary artery smooth muscle cells, face hypoxia. Ca(2+) entry pathways in mediating hypoxia-induced [Ca(2+)](i) elevation include: voltage-gated Ca(2+) channels (VGCCs), transient receptor potential (TRP) channel and Na(+)-Ca(2+) ex-changer (NCX). In the pulmonary artery, accumulated evidence strongly suggests that prostaglandins (PGs) are involved in pulmonary inflammation and cause vasoconstriction during hypoxia. In this study, we investigated the effect of arachidonic acid (AA), the upstream substrate for PGs, on hypoxia response in O(2) sensitive cells. Exogenous application of AA significantly inhibited hypoxia-induced [Ca(2+)](i) elevation. This effect was due to AA itself rather than its degenerative products. The pharmacological modulation of endogenous AA showed that the prevention of AA generation by blockage of cPLA2, diacylglycerol (DAG) lipase and fatty acid hydrolysis (FAAH), augments hypoxia-induced [Ca(2+)](i) elevation, whereas prevention of AA degeneration attenuates hypoxia-induced [Ca(2+)](i) elevation. Over-expression of COX2 enhances hypoxia-induced [Ca(2+)](i) elevation and this enhancement is reversed by exogenous AA. Our results suggest that AA inhibits hypoxia response. The dynamic alterations in cellular lipids might determine cell response to hypoxia.
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Affiliation(s)
- Fei Meng
- Department of Physiology, The Medical School, University of Birmingham, Vincent Drive, Birmingham, UK
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Pokreisz P, Marsboom G, Janssens S. Pressure overload-induced right ventricular dysfunction and remodelling in experimental pulmonary hypertension: the right heart revisited. Eur Heart J Suppl 2007. [DOI: 10.1093/eurheartj/sum021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Liu R, Hotta Y, Graveline AR, Evgenov OV, Buys ES, Bloch KD, Ichinose F, Zapol WM. Congenital NOS2 deficiency prevents impairment of hypoxic pulmonary vasoconstriction in murine ventilator-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2007; 293:L1300-5. [PMID: 17720871 DOI: 10.1152/ajplung.00396.2006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) preserves systemic arterial oxygenation during lung injury by diverting blood flow away from poorly ventilated lung regions. Ventilator-induced lung injury (VILI) is characterized by pulmonary inflammation, lung edema, and impaired HPV leading to systemic hypoxemia. Studying mice congenitally deficient in inducible nitric oxide synthase (NOS2) and wild-type mice treated with a selective NOS2 inhibitor, L-N(6)-(1-iminoethyl)lysine (L-NIL), we investigated the contribution of NOS2 to the impairment of HPV in anesthetized mice subjected to 6 h of either high tidal volume (HV(T)) or low tidal volume (LV(T)) ventilation. HPV was estimated by measuring the changes of left lung pulmonary vascular resistance (LPVR) in response to left mainstem bronchus occlusion (LMBO). LMBO increased the LPVR similarly in wild-type, NOS2(-/-), and wild-type mice treated with L-NIL 30 min before commencing 6 h of LV(T) ventilation (96% +/- 30%, 103% +/- 33%, and 80% +/- 16%, respectively, means +/- SD). HPV was impaired in wild-type mice subjected to 6 h of HV(T) ventilation (23% +/- 16%). In contrast, HPV was preserved after 6 h of HV(T) ventilation in NOS2(-/-) and wild-type mice treated with L-NIL either 30 min before or 6 h after commencing HV(T) ventilation (66% +/- 22%, 82% +/- 29%, and 85% +/- 16%, respectively). After 6 h of HV(T) ventilation and LMBO, systemic arterial oxygen tension was higher in NOS2(-/-) than in wild-type mice (192 +/- 11 vs. 171 +/- 17 mmHg; P < 0.05). We conclude that either congenital NOS2 deficiency or selective inhibition of NOS2 protects mice from the impairment of HPV occurring after 6 h of HV(T) ventilation.
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Affiliation(s)
- Rong Liu
- Dept. of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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Ko EA, Burg ED, Platoshyn O, Msefya J, Firth AL, Yuan JXJ. Functional characterization of voltage-gated K+ channels in mouse pulmonary artery smooth muscle cells. Am J Physiol Cell Physiol 2007; 293:C928-37. [PMID: 17581857 DOI: 10.1152/ajpcell.00101.2007] [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] [Indexed: 11/22/2022]
Abstract
Mice are useful animal models to study pathogenic mechanisms involved in pulmonary vascular disease. Altered expression and function of voltage-gated K(+) (K(V)) channels in pulmonary artery smooth muscle cells (PASMCs) have been implicated in the development of pulmonary arterial hypertension. K(V) currents (I(K(V))) in mouse PASMCs have not been comprehensively characterized. The main focus of this study was to determine the biophysical and pharmacological properties of I(K(V)) in freshly dissociated mouse PASMCs with the patch-clamp technique. Three distinct whole cell I(K(V)) were identified based on the kinetics of activation and inactivation: rapidly activating and noninactivating currents (in 58% of the cells tested), rapidly activating and slowly inactivating currents (23%), and slowly activating and noninactivating currents (17%). Of the cells that demonstrated the rapidly activating noninactivating current, 69% showed I(K(V)) inhibition with 4-aminopyridine (4-AP), while 31% were unaffected. Whole cell I(K(V)) were very sensitive to tetraethylammonium (TEA), as 1 mM TEA decreased the current amplitude by 32% while it took 10 mM 4-AP to decrease I(K(V)) by a similar amount (37%). Contribution of Ca(2+)-activated K(+) (K(Ca)) channels to whole cell I(K(V)) was minimal, as neither pharmacological inhibition with charybdotoxin or iberiotoxin nor perfusion with Ca(2+)-free solution had an effect on the whole cell I(K(V)). Steady-state activation and inactivation curves revealed a window K(+) current between -40 and -10 mV with a peak at -31.5 mV. Single-channel recordings revealed large-, intermediate-, and small-amplitude currents, with an averaged slope conductance of 119.4 +/- 2.7, 79.8 +/- 2.8, 46.0 +/- 2.2, and 23.6 +/- 0.6 pS, respectively. These studies provide detailed electrophysiological and pharmacological profiles of the native K(V) currents in mouse PASMCs.
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Affiliation(s)
- Eun A Ko
- Div. of Pulmonary and Critical Care Medicine, Dept. of Medicine, Univ. of California, San Diego, 9500 Gilman Dr., MC 0725, La Jolla, CA 92093-0725, USA
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Hung MS, Avner P, Rogner UC. Identification of the transcription factor ARNTL2 as a candidate gene for the type 1 diabetes locus Idd6. Hum Mol Genet 2006; 15:2732-42. [PMID: 16893914 DOI: 10.1093/hmg/ddl209] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Idd6 murine type 1 diabetes locus has been shown to control diabetes by regulating the protective activity of the peripheral immune system, as demonstrated by diabetes transfer assays using splenocytes. The analysis of three novel subcongenic (NOD.C3H nonobese. C3H) diabetes strains has confirmed the presence of at least two diabetes-related genes within the 5.8 Mb Idd6 interval with the disease protection conferred by splenocyte co-transfer being located to the 700 kb Idd6.3 subregion. This subinterval contains the circadian rhythm-related transcription factor Arntl2 (Bmal2), a homologue of the type 2 diabetes-associated ARNT (HIF1beta) gene. Arntl2 exhibited a six-fold upregulation in spleens of the NOD.C3H 6.VIII congenic strain compared with the NOD control strain, strain-specific splice variants and a large number of polymorphisms in both coding and non-coding regions. Arntl2 upregulation was not associated with changes in the expression levels of other circadian genes in the spleen, but did correlate with the upregulation of the ARNT-binding motif containing Pla2g4a gene, which has recently been described as being protective for the progression of insulitis and autoimmune diabetes in the NOD mouse via regulation of the tumour necrosis factor-alpha pathway. Our studies strongly suggest that the HIFbeta-homologous Arntl2 gene is involved in the control of type 1 diabetes.
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Affiliation(s)
- Ming-Shiu Hung
- Unité de Génétique Moléculaire Murine CNRS URA 2578, Institut Pasteur, Paris, France
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31
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Malaviya R, Ansell J, Hall L, Fahmy M, Argentieri RL, Olini GC, Pereira DW, Sur R, Cavender D. Targeting cytosolic phospholipase A2 by arachidonyl trifluoromethyl ketone prevents chronic inflammation in mice. Eur J Pharmacol 2006; 539:195-204. [PMID: 16712837 DOI: 10.1016/j.ejphar.2006.03.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 03/02/2006] [Accepted: 03/08/2006] [Indexed: 11/28/2022]
Abstract
Cytosolic phospholipase A(2) (cPLA(2)) plays a pivotal role in inflammation by catalyzing the release of arachidonic acid, a substrate for lipoxygenase and cyclooxygenase enzymes, from membrane phospholipids. In the present study we examined the role of cPLA(2) in inflammatory responses through the use of a specific inhibitor of the enzyme, cPLA(2), arachidonyl trifluoromethyl ketone (AACOCF3). Interestingly, we observed that AACOCF3 is an inhibitor of chronic but not acute inflammatory responses. Specifically, AACOCF3 inhibited phorbol 12-myristate 13-acetate (PMA)-induced chronic ear edema in mice. Additionally, oral treatment of ovalbumin-sensitized/ovalbumin-challenged BALB/c mice with 20 mg/kg AACOCF3 prevented the development of airway hyper-responsiveness in a model of asthma. Furthermore, AACOCF3 decreased cellular recruitment in the airway lumen and airway inflammation after the ovalbumin challenge. Taken together, these results suggest that a potent and specific chemical inhibitor of cPLA(2) may be useful for the treatment of chronic inflammatory diseases including rheumatoid arthritis, inflammatory bowel disease, psoriasis, and asthma.
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Affiliation(s)
- Ravi Malaviya
- Inflammation Research Team, Department of Drug Discovery, Johnson and Johnson Pharmaceutical Research and Development, LLC, Raritan, NJ 08869, USA
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Pokreisz P, Fleming I, Kiss L, Barbosa-Sicard E, Fisslthaler B, Falck JR, Hammock BD, Kim IH, Szelid Z, Vermeersch P, Gillijns H, Pellens M, Grimminger F, van Zonneveld AJ, Collen D, Busse R, Janssens S. Cytochrome P450 epoxygenase gene function in hypoxic pulmonary vasoconstriction and pulmonary vascular remodeling. Hypertension 2006; 47:762-70. [PMID: 16505204 PMCID: PMC1993904 DOI: 10.1161/01.hyp.0000208299.62535.58] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We assessed pulmonary cytochrome P450 (CYP) epoxygenase expression and activity during hypoxia and explored the effects of modulating epoxygenase activity on pulmonary hypertension. The acute hypoxic vasoconstrictor response was studied in Swiss Webster mice, who express CYP2C29 in their lungs. Animals were pretreated with vehicle, the epoxygenase inhibitor (N-methylsulfonyl-6-[2-propargyloxyphenyl] hexanamide) or an inhibitor of the soluble epoxide hydrolase. Whereas the epoxygenase inhibitor attenuated hypoxic pulmonary constriction (by 52%), the soluble epoxide hydrolase inhibitor enhanced the response (by 39%), indicating that CYP epoxygenase-derived epoxyeicosatrienoic acids elicit pulmonary vasoconstriction. Aerosol gene transfer of recombinant adenovirus containing the human CYP2C9 significantly elevated mean pulmonary artery pressure and total pulmonary resistance indices, both of which were sensitive to the inhibitor sulfaphenazole. The prolonged exposure of mice to hypoxia increased CYP2C29 expression, and transcript levels increased 5-fold after exposure to normobaric hypoxia (FIO2 0.07) for 2 hours. This was followed by a 2-fold increase in protein expression and by a significant increase in epoxyeicosatrienoic acid production after 24 hours. Chronic hypoxia (7 days) elicited pulmonary hypertension and pulmonary vascular remodeling, effects that were significantly attenuated in animals continually treated with N-methylsulfonyl-6-[2-propargyloxyphenyl] hexanamide (-46% and -55%, respectively). Our results indicate that endogenously generated epoxygenase products are associated with hypoxic pulmonary hypertension in mice and that selective epoxygenase inhibition significantly reduces acute hypoxic pulmonary vasoconstriction and chronic hypoxia-induced pulmonary vascular remodeling. These observations indicate potential novel targets for the treatment of pulmonary hypertension and highlight a pivotal role for CYP epoxygenases in pulmonary responses to hypoxia.
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Affiliation(s)
- Peter Pokreisz
- Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute of Biotechnology, University of Leuven, Belgium
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Weinmann M, Belka C, Güner D, Goecke B, Müller I, Bamberg M, Jendrossek V. Array-based comparative gene expression analysis of tumor cells with increased apoptosis resistance after hypoxic selection. Oncogene 2005; 24:5914-22. [PMID: 15897868 DOI: 10.1038/sj.onc.1208748] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tumor hypoxia is an adverse prognostic factor. In a recent study, we could demonstrate that cyclic hypoxia selects for hypoxia-tolerant tumor cells, which are cross-resistant to other stimuli of mitochondrial death pathways. In contrast, sensitivity of the cells to death-receptor ligands was mainly not affected. The aim of the present study was to further elucidate cellular changes induced by cyclic hypoxia and to identify alterations in gene expression pattern upon hypoxic selection by means of DNA-microarray analysis. Our data reveal that cyclic hypoxia resulted in the selection of cells with resistance to doxorubicine and radiation. Furthermore, hypoxic selection was accompanied by constitutive changes of the gene expression pattern with downregulation of 156 and upregulation of 82 genes. Most of the differentially regulated genes were involved in cellular responses to hypoxia and reoxygenation. While many of the genes that were downregulated upon hypoxic selection represent genes that are usually upregulated by acute hypoxia, the genes that were upregulated represent genes that are involved in stress resistance and anti-apoptotic signalling. Most importantly, hypoxic selection was not associated with changes of single apoptosis relevant genes, but with alterations in gene expression levels of a wide variety of genes indicating a more complex adaptation process.
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Affiliation(s)
- Martin Weinmann
- Department of Radiation Oncology, University of Tuebingen, Germany
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34
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Caironi P, Ichinose F, Liu R, Jones RC, Bloch KD, Zapol WM. 5-Lipoxygenase deficiency prevents respiratory failure during ventilator-induced lung injury. Am J Respir Crit Care Med 2005; 172:334-43. [PMID: 15894604 PMCID: PMC2718472 DOI: 10.1164/rccm.200501-034oc] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 05/04/2005] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Mechanical ventilation with high VT (HVT) progressively leads to lung injury and decreased efficiency of gas exchange. Hypoxic pulmonary vasoconstriction (HPV) directs blood flow to well-ventilated lung regions, preserving systemic oxygenation during pulmonary injury. Recent experimental studies have revealed an important role for leukotriene (LT) biosynthesis by 5-lipoxygenase (5LO) in the impairment of HPV by endotoxin. OBJECTIVES To investigate whether or not impairment of HPV contributes to the hypoxemia associated with HVT and to evaluate the role of LTs in ventilator-induced lung injury. METHODS We studied wild-type and 5LO-deficient mice ventilated for up to 10 hours with low VT (LVT) or HVT. RESULTS In wild-type mice, HVT, but not LVT, increased pulmonary vascular permeability and edema formation, impaired systemic oxygenation, and reduced survival. HPV, as reflected by the increase in left pulmonary vascular resistance induced by left mainstem bronchus occlusion, was markedly impaired in animals ventilated with HVT. HVT ventilation increased bronchoalveolar lavage levels of LTs and neutrophils. In 5LO-deficient mice, the HVT-induced increase of pulmonary vascular permeability and worsening of respiratory mechanics were markedly attenuated, systemic oxygenation was preserved, and survival increased. Moreover, in 5LO-deficient mice, HVT ventilation did not impair the ability of left mainstem bronchus occlusion to increase left pulmonary vascular resistance. Administration of MK886, a 5LO-activity inhibitor, or MK571, a selective cysteinyl-LT(1) receptor antagonist, largely prevented ventilator-induced lung injury. CONCLUSIONS These results indicate that LTs play a central role in the lung injury and impaired oxygenation induced by HVT ventilation.
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Affiliation(s)
- Pietro Caironi
- Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, 02114, USA
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35
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Ward JPT, Knock GA, Snetkov VA, Aaronson PI. Protein kinases in vascular smooth muscle tone--role in the pulmonary vasculature and hypoxic pulmonary vasoconstriction. Pharmacol Ther 2005; 104:207-31. [PMID: 15556675 DOI: 10.1016/j.pharmthera.2004.08.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is an adaptive mechanism that in the normal animal diverts blood away from poorly ventilated areas of the lung, thereby maintaining optimal ventilation-perfusion matching. In global hypoxia however, such as in respiratory disease or at altitude, it causes detrimental increases in pulmonary vascular resistance and pulmonary artery (PA) pressure. The precise intracellular pathways and mechanisms underlying HPV remain unclear, although it is now recognised that both an elevation in smooth muscle intracellular [Ca2+] and a concomitant increase in Ca2+ sensitivity are involved. Several key intracellular protein kinases have been proposed as components of the signal transduction pathways leading to development of HPV, specifically Rho kinase, non-receptor tyrosine kinases (NRTK), p38 mitogen activated protein (MAP) kinase, and protein kinase C (PKC). All of these have been implicated to a greater or lesser extent in pathways leading to Ca2+ sensitisation, and in some cases regulation of intracellular [Ca2+] as well. In this article, we review the role of these key protein kinases in the regulation of vascular smooth muscle (VSM) constriction, applying what is known in the systemic circulation to the pulmonary circulation and HPV. We conclude that the strongest evidence for direct involvement of protein kinases in the mechanisms of HPV concerns a central role for Rho kinase in Ca2+ sensitisation, and a potential role for Src-family kinases in both modulation of Ca2+ entry via capacitative Ca2+ entry (CCE) and activation of Rho kinase, though others are likely to have indirect or modulatory influences. In addition, we speculate that Src family kinases may provide a central interface between the proposed hypoxia-induced generation of reactive oxygen species by mitochondria and both the elevation in intracellular [Ca2+] and Rho kinase mediated Ca2+ sensitisation.
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Affiliation(s)
- Jeremy P T Ward
- Division of Asthma, Allergy and Lung Biology, Guy's, King's and St Thomas' School of Medicine, King's College London, London, UK.
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Liu R, Evgenov OV, Ichinose F. NOS3 deficiency augments hypoxic pulmonary vasoconstriction and enhances systemic oxygenation during one-lung ventilation in mice. J Appl Physiol (1985) 2005; 98:748-52. [PMID: 15465885 DOI: 10.1152/japplphysiol.00820.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitric oxide (NO), synthesized by NO synthases (NOS), plays a pivotal role in regulation of pulmonary vascular tone. To examine the role of endothelial NOS (NOS3) in hypoxic pulmonary vasoconstriction (HPV), we measured left lung pulmonary vascular resistance (LPVR), intrapulmonary shunting, and arterial Po2 (PaO2) before and during left mainstem bronchus occlusion (LMBO) in mice with and without a deletion of the gene encoding NOS3. The increase of LPVR induced by LMBO was greater in NOS3-deficient mice than in wild-type mice (151 ± 39% vs. 109 ± 36%, mean ± SD; P < 0.05). NOS3-deficient mice had a lower intrapulmonary shunt fraction than wild-type mice (17.1 ± 3.6% vs. 21.7 ± 2.4%, P < 0.05) during LMBO. Both real-time PaO2 monitoring with an intra-arterial probe and arterial blood-gas analysis during LMBO showed higher PaO2 in NOS3-deficient mice than in wild-type mice ( P < 0.05). Inhibition of all three NOS isoforms with Nω-nitro-l-arginine methyl ester (l-NAME) augmented the increase of LPVR induced by LMBO in wild-type mice (183 ± 67% in l-NAME treated vs. 109 ± 36% in saline treated, P < 0.01) but not in NOS3-deficient mice. Similarly, systemic oxygenation during one-lung ventilation was augmented by l-NAME in wild-type mice but not in NOS3-deficient mice. These findings indicate that NO derived from NOS3 modulates HPV in vivo and that inhibition of NOS3 improves systemic oxygenation during acute unilateral lung hypoxia.
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Affiliation(s)
- Rong Liu
- Dept. of Anesthesia and Critical Care, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
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Beppu H, Ichinose F, Kawai N, Jones RC, Yu PB, Zapol WM, Miyazono K, Li E, Bloch KD. BMPR-IIheterozygous mice have mild pulmonary hypertension and an impaired pulmonary vascular remodeling response to prolonged hypoxia. Am J Physiol Lung Cell Mol Physiol 2004; 287:L1241-7. [PMID: 15286002 DOI: 10.1152/ajplung.00239.2004] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heterozygous mutations of the bone morphogenetic protein type II receptor ( BMPR-II) gene have been identified in patients with primary pulmonary hypertension. The mechanisms by which these mutations contribute to the pathogenesis of primary pulmonary hypertension are not fully elucidated. To assess the impact of a heterozygous mutation of the BMPR-II gene on the pulmonary vasculature, we studied mice carrying a mutant BMPR-II allele lacking exons 4 and 5 ( BMPR-II+/−mice). BMPR-II+/−mice had increased mean pulmonary arterial pressure and pulmonary vascular resistance compared with their wild-type littermates. Histological analyses revealed that the wall thickness of muscularized pulmonary arteries (<100 μm in diameter) and the number of alveolar-capillary units were greater in BMPR-II+/−than in wild-type mice. Breathing 11% oxygen for 3 wk increased mean pulmonary arterial pressure, pulmonary vascular resistance, and hemoglobin concentration to similar levels in BMPR-II+/−and wild-type mice, but the degree of muscularization of small pulmonary arteries and formation of alveolar-capillary units were reduced in BMPR-II+/−mice. Our results suggest that, in mice, mutation of one copy of the BMPR-II gene causes pulmonary hypertension but impairs the ability of the pulmonary vasculature to remodel in response to prolonged hypoxic breathing.
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Affiliation(s)
- Hideyuki Beppu
- Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA. )
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Gilroy DW, Newson J, Sawmynaden P, Willoughby DA, Croxtall JD. A novel role for phospholipase A2 isoforms in the checkpoint control of acute inflammation. FASEB J 2004; 18:489-98. [PMID: 15003994 DOI: 10.1096/fj.03-0837com] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Acute inflammation can be considered in terms of a series of checkpoints where each phase of cellular influx, persistence, and clearance is controlled by endogenous stop and go signals. It is becoming increasingly apparent that in addition to initiating the inflammatory response, eicosanoids may also mediate resolution. This suggests there are two phases of arachidonic acid release: one at onset for the generation of proinflammatory eicosanoids and one at resolution for the synthesis of proresolving eicosanoids. What is unclear is the identity of the phospholipase (PLA2) isoforms involved in this biphasic release of arachidonic acid. We show here that type VI iPLA2 drives the onset of acute pleurisy through the synthesis of PGE2, LTB4, PAF, and IL-1beta. However, during resolution there is a switch to a sequential induction of first sPLA2 (types IIa and V) that mediates the release of PAF and lipoxin A4, which, in turn, are responsible for the subsequent induction of type IV cPLA2 that mediates the release of arachidonic acid for the synthesis of proresolving prostaglandins. This study is the first of its kind to address the respective roles of PLA2 isoforms in acute resolving inflammation and to identify type VI iPLA2 as a potentially selective target for the treatment of inflammatory diseases.
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Affiliation(s)
- Derek W Gilroy
- Department of Experimental Pathology, William Harvey Research Institute, St. Bartholomew's & The Royal London School of Medicine and Dentistry, London.
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Guibert C, Marthan R, Savineau JP. 5-HT induces an arachidonic acid-sensitive calcium influx in rat small intrapulmonary artery. Am J Physiol Lung Cell Mol Physiol 2004; 286:L1228-36. [PMID: 14751848 DOI: 10.1152/ajplung.00265.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
5-Hydroxytryptamine (5-HT) is a potent pulmonary vasoconstrictor and contributes to hypoxic pulmonary vasoconstriction and pulmonary arterial hypertension. Small intrapulmonary vessels are very sensitive to hypoxia and play a major role for blood flow regulation in the lung. Thus we have investigated the mechanisms involved in the calcium signal to 5-HT in rat small intrapulmonary artery (IPA). Effects of 5-HT were examined in isolated IPA (external diameter <250 microm) from rat. Digital imaging with fura-PE3 was used to record intracellular calcium concentration ([Ca(2+)](i)) and to follow external diameter of the vessels. 5-HT induced a sustained [Ca(2+)](i) variation that was sensitive to the inhibitor of the 5-HT(2A) receptors, ketanserin, and insensitive to voltage-dependent L-type calcium channel blockers (nitrendipine and nicardipine) or voltage-independent calcium channel antagonists (LOE-908, SKF-96365, and gadolinium). The calcium response to 5-HT was also not modified by a sarcoplasmic reticulum Ca(2+)-ATPase inhibitor (cyclopiazonic acid; CPA), which depletes intracellular calcium stores. CPA alone activated a capacitative calcium channel that was sensitive to LOE-908 and insensitive to SKF-96365 and gadolinium. The sustained calcium signal to 5-HT was partly blocked by inhibitors of arachidonic acid production (RHC-80267 and isotetrandrine) and mimicked by application of exogenous arachidonic acid. These results suggest that activation of a noncapacitative, arachidonic acid-sensitive, receptor-operated calcium channel contributes to 5-HT-induced sustained calcium increase in small IPA.
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Affiliation(s)
- Christelle Guibert
- Laboratoire de Physiologie Cellulaire Respiratoire, Institut National de la Santé et se la Recherche Médicale, Université Bordeaux 2, 146, rue Léo Saignat, 33076 Bordeaux Cedex, France.
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Wong DA, Uozumi N, Kita Y, Shimizu T. Cytosolic phospholipase A2alpha in mouse platelets. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 525:81-6. [PMID: 12751741 DOI: 10.1007/978-1-4419-9194-2_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Affiliation(s)
- Dennis A Wong
- Department of Medicine, University of Chicago, IL 60637, USA
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Nagase T, Uozumi N, Aoki-Nagase T, Terawaki K, Ishii S, Tomita T, Yamamoto H, Hashizume K, Ouchi Y, Shimizu T. A potent inhibitor of cytosolic phospholipase A2, arachidonyl trifluoromethyl ketone, attenuates LPS-induced lung injury in mice. Am J Physiol Lung Cell Mol Physiol 2003; 284:L720-6. [PMID: 12505870 DOI: 10.1152/ajplung.00396.2002] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) is an acute lung injury of high mortality rate, and sepsis syndrome is one of the most frequent causes of ARDS. Metabolites of arachidonic acid, including thromboxanes and leukotrienes, are proinflammatory mediators and potentially involved in the development of ARDS. A key enzyme for the production of these inflammatory mediators is cytosolic phospholipase A(2) (cPLA(2)). Recently, it has been reported that arachidonyl trifluoromethyl ketone (ATK) is a potent inhibitor of cPLA(2). In the present study, we hypothesized that pharmacological intervention of cPLA(2) could affect acute lung injury. To test this hypothesis, we examined the effects of ATK in a murine model of acute lung injury induced by septic syndrome. The treatment with ATK significantly attenuated lung injury, polymorphonuclear neutrophil sequestration, and deterioration of gas exchange caused by lipopolysaccharide and zymosan administration. The current observations suggest that pharmacological intervention of cPLA(2) could be a novel therapeutic approach to acute lung injury caused by sepsis syndrome.
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Affiliation(s)
- Takahide Nagase
- Department of Geriatric Medicine, Graduate School of Medicine, University of Tokyo, Japan.
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