1
|
Novel Molecular Mechanisms Involved in the Medical Treatment of Pulmonary Arterial Hypertension. Int J Mol Sci 2023; 24:ijms24044147. [PMID: 36835558 PMCID: PMC9965798 DOI: 10.3390/ijms24044147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a severe condition with a high mortality rate despite advances in diagnostic and therapeutic strategies. In recent years, significant scientific progress has been made in the understanding of the underlying pathobiological mechanisms. Since current available treatments mainly target pulmonary vasodilation, but lack an effect on the pathological changes that develop in the pulmonary vasculature, there is need to develop novel therapeutic compounds aimed at antagonizing the pulmonary vascular remodeling. This review presents the main molecular mechanisms involved in the pathobiology of PAH, discusses the new molecular compounds currently being developed for the medical treatment of PAH and assesses their potential future role in the therapeutic algorithms of PAH.
Collapse
|
2
|
Moreno-Domínguez A, Colinas O, Smani T, Ureña J, López-Barneo J. Acute oxygen sensing by vascular smooth muscle cells. Front Physiol 2023; 14:1142354. [PMID: 36935756 PMCID: PMC10020353 DOI: 10.3389/fphys.2023.1142354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
An adequate supply of oxygen (O2) is essential for most life forms on earth, making the delivery of appropriate levels of O2 to tissues a fundamental physiological challenge. When O2 levels in the alveoli and/or blood are low, compensatory adaptive reflexes are produced that increase the uptake of O2 and its distribution to tissues within a few seconds. This paper analyzes the most important acute vasomotor responses to lack of O2 (hypoxia): hypoxic pulmonary vasoconstriction (HPV) and hypoxic vasodilation (HVD). HPV affects distal pulmonary (resistance) arteries, with its homeostatic role being to divert blood to well ventilated alveoli to thereby optimize the ventilation/perfusion ratio. HVD is produced in most systemic arteries, in particular in the skeletal muscle, coronary, and cerebral circulations, to increase blood supply to poorly oxygenated tissues. Although vasomotor responses to hypoxia are modulated by endothelial factors and autonomic innervation, it is well established that arterial smooth muscle cells contain an acute O2 sensing system capable of detecting changes in O2 tension and to signal membrane ion channels, which in turn regulate cytosolic Ca2+ levels and myocyte contraction. Here, we summarize current knowledge on the nature of O2 sensing and signaling systems underlying acute vasomotor responses to hypoxia. We also discuss similarities and differences existing in O2 sensors and effectors in the various arterial territories.
Collapse
Affiliation(s)
- Alejandro Moreno-Domínguez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Olaia Colinas
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Tarik Smani
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - Juan Ureña
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- *Correspondence: José López-Barneo,
| |
Collapse
|
3
|
Pak O, Nolte A, Knoepp F, Giordano L, Pecina P, Hüttemann M, Grossman LI, Weissmann N, Sommer N. Mitochondrial oxygen sensing of acute hypoxia in specialized cells - Is there a unifying mechanism? BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148911. [PMID: 35988811 DOI: 10.1016/j.bbabio.2022.148911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Acclimation to acute hypoxia through cardiorespiratory responses is mediated by specialized cells in the carotid body and pulmonary vasculature to optimize systemic arterial oxygenation and thus oxygen supply to the tissues. Acute oxygen sensing by these cells triggers hyperventilation and hypoxic pulmonary vasoconstriction which limits pulmonary blood flow through areas of low alveolar oxygen content. Oxygen sensing of acute hypoxia by specialized cells thus is a fundamental pre-requisite for aerobic life and maintains systemic oxygen supply. However, the primary oxygen sensing mechanism and the question of a common mechanism in different specialized oxygen sensing cells remains unresolved. Recent studies unraveled basic oxygen sensing mechanisms involving the mitochondrial cytochrome c oxidase subunit 4 isoform 2 that is essential for the hypoxia-induced release of mitochondrial reactive oxygen species and subsequent acute hypoxic responses in both, the carotid body and pulmonary vasculature. This review compares basic mitochondrial oxygen sensing mechanisms in the pulmonary vasculature and the carotid body.
Collapse
Affiliation(s)
- Oleg Pak
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Anika Nolte
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Fenja Knoepp
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Luca Giordano
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Petr Pecina
- Laboratory of Bioenergetics, Institute of Physiology CAS, Prague, Czech Republic
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA
| | - Lawrence I Grossman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA
| | - Norbert Weissmann
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Natascha Sommer
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.
| |
Collapse
|
4
|
Redel-Traub G, Sampson KJ, Kass RS, Bohnen MS. Potassium Channels as Therapeutic Targets in Pulmonary Arterial Hypertension. Biomolecules 2022; 12:1341. [PMID: 36291551 PMCID: PMC9599705 DOI: 10.3390/biom12101341] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 12/08/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a devastating disease with high morbidity and mortality. Deleterious remodeling in the pulmonary arterial system leads to irreversible arterial constriction and elevated pulmonary arterial pressures, right heart failure, and eventually death. The difficulty in treating PAH stems in part from the complex nature of disease pathogenesis, with several signaling compounds known to be involved (e.g., endothelin-1, prostacyclins) which are indeed targets of PAH therapy. Over the last decade, potassium channelopathies were established as novel causes of PAH. More specifically, loss-of-function mutations in the KCNK3 gene that encodes the two-pore-domain potassium channel KCNK3 (or TASK-1) and loss-of-function mutations in the ABCC8 gene that encodes a key subunit, SUR1, of the ATP-sensitive potassium channel (KATP) were established as the first two potassium channelopathies in human cohorts with pulmonary arterial hypertension. Moreover, voltage-gated potassium channels (Kv) represent a third family of potassium channels with genetic changes observed in association with PAH. While other ion channel genes have since been reported in association with PAH, this review focuses on KCNK3, KATP, and Kv potassium channels as promising therapeutic targets in PAH, with recent experimental pharmacologic discoveries significantly advancing the field.
Collapse
Affiliation(s)
- Gabriel Redel-Traub
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Kevin J. Sampson
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Robert S. Kass
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Michael S. Bohnen
- Division of Cardiology, Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| |
Collapse
|
5
|
Ortiz M, Loidl F, Vázquez‐Borsetti P. Transition to extrauterine life and the modeling of perinatal asphyxia in rats. WIREs Mech Dis 2022; 14:e1568. [DOI: 10.1002/wsbm.1568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Mauro Ortiz
- Universidad de Buenos Aires Buenos Aires Argentina
| | - Fabián Loidl
- Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires Argentina
| | | |
Collapse
|
6
|
Kumar R, Soni H, Afolabi JM, Kanthakumar P, Mankuzhy PD, Iwhiwhu SA, Adebiyi A. Induction of reactive oxygen species by mechanical stretch drives endothelin production in neonatal pig renal epithelial cells. Redox Biol 2022; 55:102394. [PMID: 35841629 PMCID: PMC9289874 DOI: 10.1016/j.redox.2022.102394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 06/23/2022] [Accepted: 07/01/2022] [Indexed: 11/23/2022] Open
Abstract
Vasoactive endothelin (ET) is generated by ET converting enzyme (ECE)-induced proteolytic processing of pro-molecule big ET to biologically active peptides. H2O2 has been shown to increase the expression of ECE1 via transactivation of its promoter. The present study demonstrates that H2O2 triggered ECE1-dependent ET1-3 production in neonatal pig proximal tubule (PT) epithelial cells. A uniaxial stretch of PT cells decreased catalase, increased NADPH oxidase (NOX)2 and NOX4, and increased H2O2 levels. Stretch also increased cellular ECE1, an effect reversed by EUK-134 (a synthetic superoxide dismutase/catalase mimetic), NOX inhibitor apocynin, and siRNA-mediated knockdown of NOX2 and NOX4. Short-term unilateral ureteral obstruction (UUO), an inducer of renal tubular cell stretch and oxidative stress, increased renal ET1-3 generation and vascular resistance (RVR) in neonatal pigs. Despite removing the obstruction, UUO-induced increase in RVR persisted, resulting in early acute kidney injury (AKI). ET receptor (ETR)-operated Ca2+ entry in renal microvascular smooth muscle (SM) via transient receptor potential channel 3 (TRPC3) channels reduced renal blood flow and increased RVR. Although acute reversible UUO (rUUO) did not change protein expression levels of ETR and TRPC3 in renal microvessels, inhibition of ECE1, ETR, and TRPC3 protected against renal hypoperfusion, RVR increase, and early AKI. These data suggest that mechanical stretch-driven oxyradical generation stimulates ET production in neonatal pig renal epithelial cells. ET activates renal microvascular SM TRPC3, leading to persistent vasoconstriction and reduction in renal blood flow. These mechanisms may underlie rUUO-induced renal insufficiency in infants.
Collapse
Affiliation(s)
- Ravi Kumar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Hitesh Soni
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jeremiah M Afolabi
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Praghalathan Kanthakumar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Pratheesh D Mankuzhy
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Samson A Iwhiwhu
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Adebowale Adebiyi
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
| |
Collapse
|
7
|
Zhuang XL, Zhu ZL, Huang QH, Yan FR, Zheng SY, Lai SM, Jiao HX, Lin MJ. High magnesium mitigates the vasoconstriction mediated by different types of calcium influx from monocrotaline-induced pulmonary hypertensive rats. Exp Physiol 2022; 107:359-373. [PMID: 35193162 DOI: 10.1113/ep090029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 02/07/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? The aim was to examine and explore the involvement of Mg2+ in mitigating the vasoconstriction in PAs and sPAs in the MCT-PAH rat model. What are the main finding and its importance? 1.Both SOCE- and ROCE-mediated vasoconstriction enhanced in the MCT-PAH model. 2.High magnesium inhibited vasoconstriction due to directly antagonizing Ca2+ and increasing NO release. 3.The inhibition effect of high magnesium was more notable in sPA. ABSTRACT Increased extracellular magnesium concentration ([Mg2+ ]e ) has been evidenced to attenuate the endothelin-1 (ET-1)-induced contractile response via the release of nitric oxide (NO) from the endothelium in proximal pulmonary arteries (PAs) of chronic hypoxic (CH) mice. Here we further examined the involvement of Mg2+ in the inhibition of vasoconstriction in PAs and distal smaller pulmonary arteries (sPAs) in a monocrotaline-induced pulmonary arterial hypertension (MCT-PAH) rat model. The data showed that in control rats, vasoconstriction in sPAs is more intense than that in PAs. In MCT-PAH rats, the store-operated Ca2+ entry (SOCE)-, and receptor-operated Ca2+ entry (ROCE)-mediated contraction was significantly strengthened. However, there was no upregulation of the vasoconstriction mediated by voltage-dependent calcium entry (VDCE). Furthermore, high magnesium greatly inhibited the VDCE-mediated contraction in PAs instead of sPAs, which was opposite to the ROCE-mediated contraction. Moreover, MCT pretreatment partly eliminated the endothelium-dependent vasodilation in PAs, which in sPAs, however, was still promoted by magnesium due to the increased NO release in pulmonary microvascular endothelial cells (PMVECs). In conclusion, the findings suggest that both SOCE- and ROCE-mediated vasoconstriction in the MCT-PAH model are enhanced, especially in sPAs. The inhibition effect of high magnesium on vasoconstriction can be achieved partly by its direct role as a Ca2+ antagonist and partly by increasing the NO release in PMVECs. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Xiao-Ling Zhuang
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China.,Department of Pathology, Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Provinece, PR China
| | - Zhuang-Li Zhu
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China
| | - Qiu-Hong Huang
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China.,School of Basic Medicine, Quanzhou Medical College, Quanzhou, Fujian Provinece, PR China
| | - Fu-Rong Yan
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China.,Center for Molecular Diagnosis and Therapy, Respiratory Medicine Center of Fujian Provinece, Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian, PR China
| | - Si-Yi Zheng
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China
| | - Su-Mei Lai
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China
| | - Hai-Xia Jiao
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China
| | - Mo-Jun Lin
- Key Laboratory of Fujian Province Universities on Ion Channel and Signal Transduction in Cardiovascular Diseases, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Provinece, People's Republic of China
| |
Collapse
|
8
|
Mitochondrial iron-sulfur clusters: Structure, function, and an emerging role in vascular biology. Redox Biol 2021; 47:102164. [PMID: 34656823 PMCID: PMC8577454 DOI: 10.1016/j.redox.2021.102164] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/04/2021] [Accepted: 10/08/2021] [Indexed: 12/31/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are essential cofactors most commonly known for their role mediating electron transfer within the mitochondrial respiratory chain. The Fe-S cluster pathways that function within the respiratory complexes are highly conserved between bacteria and the mitochondria of eukaryotic cells. Within the electron transport chain, Fe-S clusters play a critical role in transporting electrons through Complexes I, II and III to cytochrome c, before subsequent transfer to molecular oxygen. Fe-S clusters are also among the binding sites of classical mitochondrial inhibitors, such as rotenone, and play an important role in the production of mitochondrial reactive oxygen species (ROS). Mitochondrial Fe-S clusters also play a critical role in the pathogenesis of disease. High levels of ROS produced at these sites can cause cell injury or death, however, when produced at low levels can serve as signaling molecules. For example, Ndufs2, a Complex I subunit containing an Fe-S center, N2, has recently been identified as a redox-sensitive oxygen sensor, mediating homeostatic oxygen-sensing in the pulmonary vasculature and carotid body. Fe-S clusters are emerging as transcriptionally-regulated mediators in disease and play a crucial role in normal physiology, offering potential new therapeutic targets for diseases including malaria, diabetes, and cancer.
Collapse
|
9
|
Yoo HY, Kim SJ. Oxygen-dependent regulation of ion channels: acute responses, post-translational modification, and response to chronic hypoxia. Pflugers Arch 2021; 473:1589-1602. [PMID: 34142209 DOI: 10.1007/s00424-021-02590-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/15/2021] [Accepted: 05/30/2021] [Indexed: 12/19/2022]
Abstract
Oxygen is a vital element for the survival of cells in multicellular aerobic organisms such as mammals. Lack of O2 availability caused by environmental or pathological conditions leads to hypoxia. Active oxygen distribution systems (pulmonary and circulatory) and their neural control mechanisms ensure that cells and tissues remain oxygenated. However, O2-carrying blood cells as well as immune and various parenchymal cells experience wide variations in partial pressure of oxygen (PO2) in vivo. Hence, the reactive modulation of the functions of the oxygen distribution systems and their ability to sense PO2 are critical. Elucidating the physiological responses of cells to variations in PO2 and determining the PO2-sensing mechanisms at the biomolecular level have attracted considerable research interest in the field of physiology. Herein, we review the current knowledge regarding ion channel-dependent oxygen sensing and associated signalling pathways in mammals. First, we present the recent findings on O2-sensing ion channels in representative chemoreceptor cells as well as in other types of cells such as immune cells. Furthermore, we highlight the transcriptional regulation of ion channels under chronic hypoxia and its physiological implications and summarize the findings of studies on the post-translational modification of ion channels under hypoxic or ischemic conditions.
Collapse
Affiliation(s)
- Hae Young Yoo
- Department of Nursing, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
| |
Collapse
|
10
|
Jain PP, Hosokawa S, Xiong M, Babicheva A, Zhao T, Rodriguez M, Rahimi S, Pourhashemi K, Balistrieri F, Lai N, Malhotra A, Shyy JYJ, Valdez-Jasso D, Thistlethwaite PA, Makino A, Yuan JXJ. Revisiting the mechanism of hypoxic pulmonary vasoconstriction using isolated perfused/ventilated mouse lung. Pulm Circ 2020; 10:2045894020956592. [PMID: 33282184 PMCID: PMC7691930 DOI: 10.1177/2045894020956592] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/16/2020] [Indexed: 12/13/2022] Open
Abstract
Hypoxic Pulmonary Vasoconstriction (HPV) is an important physiological mechanism of the lungs that matches perfusion to ventilation thus maximizing O2 saturation of the venous blood within the lungs. This study emphasizes on principal pathways in the initiation and modulation of hypoxic pulmonary vasoconstriction with a primary focus on the role of Ca2+ signaling and Ca2+ influx pathways in hypoxic pulmonary vasoconstriction. We used an ex vivo model, isolated perfused/ventilated mouse lung to evaluate hypoxic pulmonary vasoconstriction. Alveolar hypoxia (utilizing a mini ventilator) rapidly and reversibly increased pulmonary arterial pressure due to hypoxic pulmonary vasoconstriction in the isolated perfused/ventilated lung. By applying specific inhibitors for different membrane receptors and ion channels through intrapulmonary perfusion solution in isolated lung, we were able to define the targeted receptors and channels that regulate hypoxic pulmonary vasoconstriction. We show that extracellular Ca2+ or Ca2+ influx through various Ca2+-permeable channels in the plasma membrane is required for hypoxic pulmonary vasoconstriction. Removal of extracellular Ca2+ abolished hypoxic pulmonary vasoconstriction, while blockade of L-type voltage-dependent Ca2+ channels (with nifedipine), non-selective cation channels (with 30 µM SKF-96365), and TRPC6/TRPV1 channels (with 1 µM SAR-7334 and 30 µM capsazepine, respectively) significantly and reversibly inhibited hypoxic pulmonary vasoconstriction. Furthermore, blockers of Ca2+-sensing receptors (by 30 µM NPS2143, an allosteric Ca2+-sensing receptors inhibitor) and Notch (by 30 µM DAPT, a γ-secretase inhibitor) also attenuated hypoxic pulmonary vasoconstriction. These data indicate that Ca2+ influx in pulmonary arterial smooth muscle cells through voltage-dependent, receptor-operated, and store-operated Ca2+ entry pathways all contribute to initiation of hypoxic pulmonary vasoconstriction. The extracellular Ca2+-mediated activation of Ca2+-sensing receptors and the cell-cell interaction via Notch ligands and receptors contribute to the regulation of hypoxic pulmonary vasoconstriction.
Collapse
Affiliation(s)
- Pritesh P. Jain
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Susumu Hosokawa
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
- Department of Pediatrics, Tokyo Medical
and Dental University, Tokyo, Japan
| | - Mingmei Xiong
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
- Department of Critical Medicine, The
Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Aleksandra Babicheva
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Tengteng Zhao
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Marisela Rodriguez
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Shamin Rahimi
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Kiana Pourhashemi
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Francesca Balistrieri
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Ning Lai
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - Atul Malhotra
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| | - John Y.-J. Shyy
- Division of Cardiovascular Medicine,
Department of Medicine, University of California, San Diego, USA
| | | | | | - Ayako Makino
- Division of Endocrinology and
Metabolism, University of California, San Diego, CA, USA
| | - Jason X.-J. Yuan
- Section of Physiology, Division of
Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego,
CA, USA
| |
Collapse
|
11
|
Le Ribeuz H, Capuano V, Girerd B, Humbert M, Montani D, Antigny F. Implication of Potassium Channels in the Pathophysiology of Pulmonary Arterial Hypertension. Biomolecules 2020; 10:biom10091261. [PMID: 32882918 PMCID: PMC7564204 DOI: 10.3390/biom10091261] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/24/2020] [Accepted: 08/27/2020] [Indexed: 02/06/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a rare and severe cardiopulmonary disease without curative treatments. PAH is a multifactorial disease that involves genetic predisposition, epigenetic factors, and environmental factors (drugs, toxins, viruses, hypoxia, and inflammation), which contribute to the initiation or development of irreversible remodeling of the pulmonary vessels. The recent identification of loss-of-function mutations in KCNK3 (KCNK3 or TASK-1) and ABCC8 (SUR1), or gain-of-function mutations in ABCC9 (SUR2), as well as polymorphisms in KCNA5 (Kv1.5), which encode two potassium (K+) channels and two K+ channel regulatory subunits, has revived the interest of ion channels in PAH. This review focuses on KCNK3, SUR1, SUR2, and Kv1.5 channels in pulmonary vasculature and discusses their pathophysiological contribution to and therapeutic potential in PAH.
Collapse
Affiliation(s)
- Hélène Le Ribeuz
- Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin-Bicêtre, France; (H.L.R.); (V.C.); (B.G.); (M.H.); (D.M.)
- INSERM UMR_S 999, Hypertension pulmonaire, Physiopathologie et Innovation Thérapeutique, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France
- Assistance Publique—Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l’Hypertension Pulmonaire, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France
| | - Véronique Capuano
- Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin-Bicêtre, France; (H.L.R.); (V.C.); (B.G.); (M.H.); (D.M.)
- INSERM UMR_S 999, Hypertension pulmonaire, Physiopathologie et Innovation Thérapeutique, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France
- Assistance Publique—Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l’Hypertension Pulmonaire, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France
| | - Barbara Girerd
- Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin-Bicêtre, France; (H.L.R.); (V.C.); (B.G.); (M.H.); (D.M.)
- INSERM UMR_S 999, Hypertension pulmonaire, Physiopathologie et Innovation Thérapeutique, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France
- Assistance Publique—Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l’Hypertension Pulmonaire, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France
| | - Marc Humbert
- Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin-Bicêtre, France; (H.L.R.); (V.C.); (B.G.); (M.H.); (D.M.)
- INSERM UMR_S 999, Hypertension pulmonaire, Physiopathologie et Innovation Thérapeutique, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France
- Assistance Publique—Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l’Hypertension Pulmonaire, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France
| | - David Montani
- Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin-Bicêtre, France; (H.L.R.); (V.C.); (B.G.); (M.H.); (D.M.)
- INSERM UMR_S 999, Hypertension pulmonaire, Physiopathologie et Innovation Thérapeutique, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France
- Assistance Publique—Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l’Hypertension Pulmonaire, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France
| | - Fabrice Antigny
- Faculté de Médecine, Université Paris-Saclay, 94270 Le Kremlin-Bicêtre, France; (H.L.R.); (V.C.); (B.G.); (M.H.); (D.M.)
- INSERM UMR_S 999, Hypertension pulmonaire, Physiopathologie et Innovation Thérapeutique, Hôpital Marie Lannelongue, 92350 Le Plessis-Robinson, France
- Assistance Publique—Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l’Hypertension Pulmonaire, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France
- Correspondence: or ; Tel.: +33-1-40-94-22-99
| |
Collapse
|
12
|
Dasgupta A, Wu D, Tian L, Xiong PY, Dunham-Snary KJ, Chen KH, Alizadeh E, Motamed M, Potus F, Hindmarch CCT, Archer SL. Mitochondria in the Pulmonary Vasculature in Health and Disease: Oxygen-Sensing, Metabolism, and Dynamics. Compr Physiol 2020; 10:713-765. [PMID: 32163206 DOI: 10.1002/cphy.c190027] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In lung vascular cells, mitochondria serve a canonical metabolic role, governing energy homeostasis. In addition, mitochondria exist in dynamic networks, which serve noncanonical functions, including regulation of redox signaling, cell cycle, apoptosis, and mitochondrial quality control. Mitochondria in pulmonary artery smooth muscle cells (PASMC) are oxygen sensors and initiate hypoxic pulmonary vasoconstriction. Acquired dysfunction of mitochondrial metabolism and dynamics contribute to a cancer-like phenotype in pulmonary arterial hypertension (PAH). Acquired mitochondrial abnormalities, such as increased pyruvate dehydrogenase kinase (PDK) and pyruvate kinase muscle isoform 2 (PKM2) expression, which increase uncoupled glycolysis (the Warburg phenomenon), are implicated in PAH. Warburg metabolism sustains energy homeostasis by the inhibition of oxidative metabolism that reduces mitochondrial apoptosis, allowing unchecked cell accumulation. Warburg metabolism is initiated by the induction of a pseudohypoxic state, in which DNA methyltransferase (DNMT)-mediated changes in redox signaling cause normoxic activation of HIF-1α and increase PDK expression. Furthermore, mitochondrial division is coordinated with nuclear division through a process called mitotic fission. Increased mitotic fission in PAH, driven by increased fission and reduced fusion favors rapid cell cycle progression and apoptosis resistance. Downregulation of the mitochondrial calcium uniporter complex (MCUC) occurs in PAH and is one potential unifying mechanism linking Warburg metabolism and mitochondrial fission. Mitochondrial metabolic and dynamic disorders combine to promote the hyperproliferative, apoptosis-resistant, phenotype in PAH PASMC, endothelial cells, and fibroblasts. Understanding the molecular mechanism regulating mitochondrial metabolism and dynamics has permitted identification of new biomarkers, nuclear and CT imaging modalities, and new therapeutic targets for PAH. © 2020 American Physiological Society. Compr Physiol 10:713-765, 2020.
Collapse
Affiliation(s)
- Asish Dasgupta
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Danchen Wu
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Lian Tian
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Ping Yu Xiong
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | | | - Kuang-Hueih Chen
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Elahe Alizadeh
- Department of Medicine, Queen's Cardiopulmonary Unit (QCPU), Translational Institute of Medicine (TIME), Queen's University, Kingston, Ontario, Canada
| | - Mehras Motamed
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - François Potus
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Charles C T Hindmarch
- Department of Medicine, Queen's Cardiopulmonary Unit (QCPU), Translational Institute of Medicine (TIME), Queen's University, Kingston, Ontario, Canada
| | - Stephen L Archer
- Department of Medicine, Queen's University, Kingston, Ontario, Canada.,Kingston Health Sciences Centre, Kingston, Ontario, Canada.,Providence Care Hospital, Kingston, Ontario, Canada
| |
Collapse
|
13
|
Zuniga-Hertz JP, Patel HH. The Evolution of Cholesterol-Rich Membrane in Oxygen Adaption: The Respiratory System as a Model. Front Physiol 2019; 10:1340. [PMID: 31736773 PMCID: PMC6828933 DOI: 10.3389/fphys.2019.01340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/08/2019] [Indexed: 12/14/2022] Open
Abstract
The increase in atmospheric oxygen levels imposed significant environmental pressure on primitive organisms concerning intracellular oxygen concentration management. Evidence suggests the rise of cholesterol, a key molecule for cellular membrane organization, as a cellular strategy to restrain free oxygen diffusion under the new environmental conditions. During evolution and the increase in organismal complexity, cholesterol played a pivotal role in the establishment of novel and more complex functions associated with lipid membranes. Of these, caveolae, cholesterol-rich membrane domains, are signaling hubs that regulate important in situ functions. Evolution resulted in complex respiratory systems and molecular response mechanisms that ensure responses to critical events such as hypoxia facilitated oxygen diffusion and transport in complex organisms. Caveolae have been structurally and functionally associated with respiratory systems and oxygen diffusion control through their relationship with molecular response systems like hypoxia-inducible factors (HIF), and particularly as a membrane-localized oxygen sensor, controlling oxygen diffusion balanced with cellular physiological requirements. This review will focus on membrane adaptations that contribute to regulating oxygen in living systems.
Collapse
Affiliation(s)
- Juan Pablo Zuniga-Hertz
- Department of Anesthesiology, VA San Diego Healthcare System, University of California, San Diego, San Diego, CA, United States
| | - Hemal H Patel
- Department of Anesthesiology, VA San Diego Healthcare System, University of California, San Diego, San Diego, CA, United States
| |
Collapse
|
14
|
Weise-Cross L, Resta TC, Jernigan NL. Redox Regulation of Ion Channels and Receptors in Pulmonary Hypertension. Antioxid Redox Signal 2019; 31:898-915. [PMID: 30569735 PMCID: PMC7061297 DOI: 10.1089/ars.2018.7699] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 12/11/2018] [Indexed: 02/06/2023]
Abstract
Significance: Pulmonary hypertension (PH) is characterized by elevated vascular resistance due to vasoconstriction and remodeling of the normally low-pressure pulmonary vasculature. Redox stress contributes to the pathophysiology of this disease by altering the regulation and activity of membrane receptors, K+ channels, and intracellular Ca2+ homeostasis. Recent Advances: Antioxidant therapies have had limited success in treating PH, leading to a growing appreciation that reductive stress, in addition to oxidative stress, plays a role in metabolic and cell signaling dysfunction in pulmonary vascular cells. Reactive oxygen species generation from mitochondria and NADPH oxidases has substantial effects on K+ conductance and membrane potential, and both receptor-operated and store-operated Ca2+ entry. Critical Issues: Some specific redox changes resulting from oxidation, S-nitrosylation, and S-glutathionylation are known to modulate membrane receptor and ion channel activity in PH. However, many sites of regulation that have been elucidated in nonpulmonary cell types have not been tested in the pulmonary vasculature, and context-specific molecular mechanisms are lacking. Future Directions: Here, we review what is known about redox regulation of membrane receptors and ion channels in PH. Further investigation of the mechanisms involved is needed to better understand the etiology of PH and develop better targeted treatment strategies.
Collapse
Affiliation(s)
- Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C. Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| |
Collapse
|
15
|
Tian H, Fan F, Geng J, Deng J, Tian H. Beraprost Upregulates KV Channel Expression and Function via EP4 Receptor in Pulmonary Artery Smooth Muscle Cells Obtained from Rats with Hypoxia-Induced Pulmonary Hypertension. J Vasc Res 2019; 56:204-214. [PMID: 31189158 DOI: 10.1159/000500424] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 04/15/2019] [Indexed: 11/19/2022] Open
Abstract
The reduced expression and function of voltage-dependent potassium (KV) channels have been involved in the pathogenesis of hypoxia-induced pulmonary hypertension (HPH), leading to pulmonary vasoconstriction and vascular remodeling, while the upregulation of KV channels is of therapeutic significance for pulmonary hypertension. Beraprost sodium (BPS) has been shown to be effective in patients with pulmonary hypertension. However, the effect of BPS on O2-sensitive KV channels in pulmonary artery smooth muscle cells (PASMCs) remains unclear. In the present study, the effect of BPS on rats with HPH was observed, and the influence of BPS on the expression and function of O2-sensitive KV channels in PASMCs was investigated. The results revealed that BPS reduced mean pulmonary artery pressure, suppressed right ventricular hypertrophy, and attenuated the remodeling of pulmonary arteries in rats exposed to discontinuous hypoxia for 4 weeks (8 h/day). This was accompanied with the significantly upregulated expression of KV channel α-subunits (KV1.2, KV1.5 and KV2.1) and O2-sensitive voltage-gated K+ (KV) channel current (IK(V)) in small pulmonary arteries in HPH model rats, as well as in hypoxia-induced PASMCs. Furthermore, in vitrostudies have revealed that the upregulation of BPS on O2-sensitive KV channels was significantly inhibited after treatment with prostaglandin E2 receptor subtype EP4 antagonist GW627368X. Taken together, these results suggest that BPS attenuates the development of HPH through the upregulation of O2-sensitive KV channels, which was probably via the EP4 receptor-related pathway.
Collapse
Affiliation(s)
- Hua Tian
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Fenling Fan
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jie Geng
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jizhao Deng
- Department of Cardiology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Hongyan Tian
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China,
| |
Collapse
|
16
|
Dogan MF, Yildiz O, Arslan SO, Ulusoy KG. Potassium channels in vascular smooth muscle: a pathophysiological and pharmacological perspective. Fundam Clin Pharmacol 2019; 33:504-523. [PMID: 30851197 DOI: 10.1111/fcp.12461] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/28/2019] [Accepted: 03/07/2019] [Indexed: 12/23/2022]
Abstract
Potassium (K+ ) ion channel activity is an important determinant of vascular tone by regulating cell membrane potential (MP). Activation of K+ channels leads to membrane hyperpolarization and subsequently vasodilatation, while inhibition of the channels causes membrane depolarization and then vasoconstriction. So far five distinct types of K+ channels have been identified in vascular smooth muscle cells (VSMCs): Ca+2 -activated K+ channels (BKC a ), voltage-dependent K+ channels (KV ), ATP-sensitive K+ channels (KATP ), inward rectifier K+ channels (Kir ), and tandem two-pore K+ channels (K2 P). The activity and expression of vascular K+ channels are changed during major vascular diseases such as hypertension, pulmonary hypertension, hypercholesterolemia, atherosclerosis, and diabetes mellitus. The defective function of K+ channels is commonly associated with impaired vascular responses and is likely to become as a result of changes in K+ channels during vascular diseases. Increased K+ channel function and expression may also help to compensate for increased abnormal vascular tone. There are many pharmacological and genotypic studies which were carried out on the subtypes of K+ channels expressed in variable amounts in different vascular beds. Modulation of K+ channel activity by molecular approaches and selective drug development may be a novel treatment modality for vascular dysfunction in the future. This review presents the basic properties, physiological functions, pathophysiological, and pharmacological roles of the five major classes of K+ channels that have been determined in VSMCs.
Collapse
Affiliation(s)
- Muhammed Fatih Dogan
- Department of Pharmacology, Ankara Yildirim Beyazit University, Bilkent, Ankara, 06010, Turkey
| | - Oguzhan Yildiz
- Department of Pharmacology, Gulhane Faculty of Medicine, University of Health Sciences, Etlik, Ankara, 06170, Turkey
| | - Seyfullah Oktay Arslan
- Department of Pharmacology, Ankara Yildirim Beyazit University, Bilkent, Ankara, 06010, Turkey
| | - Kemal Gokhan Ulusoy
- Department of Pharmacology, Gulhane Faculty of Medicine, University of Health Sciences, Etlik, Ankara, 06170, Turkey
| |
Collapse
|
17
|
Dunham-Snary KJ, Wu D, Potus F, Sykes EA, Mewburn JD, Charles RL, Eaton P, Sultanian RA, Archer SL. Ndufs2, a Core Subunit of Mitochondrial Complex I, Is Essential for Acute Oxygen-Sensing and Hypoxic Pulmonary Vasoconstriction. Circ Res 2019; 124:1727-1746. [PMID: 30922174 DOI: 10.1161/circresaha.118.314284] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
RATIONALE Hypoxic pulmonary vasoconstriction (HPV) optimizes systemic oxygen delivery by matching ventilation to perfusion. HPV is intrinsic to pulmonary artery smooth muscle cells (PASMCs). Hypoxia dilates systemic arteries, including renal arteries. Hypoxia is sensed by changes in mitochondrial-derived reactive oxygen species, notably hydrogen peroxide (H2O2) ([H2O2]mito). Decreases in [H2O2]mito elevate pulmonary vascular tone by increasing intracellular calcium ([Ca2+]i) through reduction-oxidation regulation of ion channels. Although HPV is mimicked by the Complex I inhibitor, rotenone, the molecular identity of the O2 sensor is unknown. OBJECTIVE To determine the role of Ndufs2 (NADH [nicotinamide adenine dinucleotide] dehydrogenase [ubiquinone] iron-sulfur protein 2), Complex I's rotenone binding site, in pulmonary vascular oxygen-sensing. METHODS AND RESULTS Mitochondria-conditioned media from pulmonary and renal mitochondria isolated from normoxic and chronically hypoxic rats were infused into an isolated lung bioassay. Mitochondria-conditioned media from normoxic lungs contained more H2O2 than mitochondria-conditioned media from chronic hypoxic lungs or kidneys and uniquely attenuated HPV via a catalase-dependent mechanism. In PASMC, acute hypoxia decreased H2O2 within 112±7 seconds, followed, within 205±34 seconds, by increased intracellular calcium concentration, [Ca2+]i. Hypoxia had no effects on [Ca2+]i in renal artery SMC. Hypoxia decreases both cytosolic and mitochondrial H2O2 in PASMC while increasing cytosolic H2O2 in renal artery SMC. Ndufs2 expression was greater in PASMC versus renal artery SMC. Lung Ndufs2 cysteine residues became reduced during acute hypoxia and both hypoxia and reducing agents caused functional inhibition of Complex I. In PASMC, siNdufs2 (cells/tissue treated with Ndufs2 siRNA) decreased normoxic H2O2, prevented hypoxic increases in [Ca2+]i, and mimicked aspects of chronic hypoxia, including decreasing Complex I activity, elevating the nicotinamide adenine dinucleotide (NADH/NAD+) ratio and decreasing expression of the O2-sensitive ion channel, Kv1.5. Knocking down another Fe-S center within Complex I (Ndufs1, NADH [nicotinamide adenine dinucleotide] dehydrogenase [ubiquinone] iron-sulfur protein 1) or other mitochondrial subunits proposed as putative oxygen sensors (Complex III's Rieske Fe-S center and COX4i2 [cytochrome c oxidase subunit 4 isoform 2] in Complex IV) had no effect on hypoxic increases in [Ca2+]i. In vivo, siNdufs2 significantly decreased hypoxia- and rotenone-induced constriction while enhancing phenylephrine-induced constriction. CONCLUSIONS Ndufs2 is essential for oxygen-sensing and HPV.
Collapse
Affiliation(s)
- Kimberly J Dunham-Snary
- From the Department of Medicine, Queen's University, Kingston, ON, Canada (K.J.D.-S., D.W., F.P., E.A.S., J.D.M., S.L.A.)
| | - Danchen Wu
- From the Department of Medicine, Queen's University, Kingston, ON, Canada (K.J.D.-S., D.W., F.P., E.A.S., J.D.M., S.L.A.)
| | - François Potus
- From the Department of Medicine, Queen's University, Kingston, ON, Canada (K.J.D.-S., D.W., F.P., E.A.S., J.D.M., S.L.A.)
| | - Edward A Sykes
- From the Department of Medicine, Queen's University, Kingston, ON, Canada (K.J.D.-S., D.W., F.P., E.A.S., J.D.M., S.L.A.)
| | - Jeffrey D Mewburn
- From the Department of Medicine, Queen's University, Kingston, ON, Canada (K.J.D.-S., D.W., F.P., E.A.S., J.D.M., S.L.A.)
| | - Rebecca L Charles
- British Heart Foundation Centre of Excellence, King´s College London, The Rayne Institute, St Thomas' Hospital, London, United Kingdom (R.L.C., P.E.)
| | - Philip Eaton
- British Heart Foundation Centre of Excellence, King´s College London, The Rayne Institute, St Thomas' Hospital, London, United Kingdom (R.L.C., P.E.)
| | - Richard A Sultanian
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada (R.A.S.)
| | - Stephen L Archer
- From the Department of Medicine, Queen's University, Kingston, ON, Canada (K.J.D.-S., D.W., F.P., E.A.S., J.D.M., S.L.A.).,Queen's Cardiopulmonary Unit (QCPU), Translational Institute of Medicine (TIME), Department of Medicine, Queen's University, Kingston, ON, Canada (S.L.A.)
| |
Collapse
|
18
|
Lv Y, Fu L, Zhang Z, Gu W, Luo X, Zhong Y, Xu S, Wang Y, Yan L, Li M, Du L. Increased Expression of MicroRNA-206 Inhibits Potassium Voltage-Gated Channel Subfamily A Member 5 in Pulmonary Arterial Smooth Muscle Cells and Is Related to Exaggerated Pulmonary Artery Hypertension Following Intrauterine Growth Retardation in Rats. J Am Heart Assoc 2019; 8:e010456. [PMID: 30636484 PMCID: PMC6497345 DOI: 10.1161/jaha.118.010456] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/11/2018] [Indexed: 12/18/2022]
Abstract
Background Intrauterine growth retardation ( IUGR ) is related to pulmonary artery hypertension in adults, and mi croRNA -206 (miR-206) is proposed to affect the proliferation and apoptosis of pulmonary artery smooth muscle cells ( PASMC s) via post-transcriptional regulation. Methods and Results In an IUGR rat model, we found that the expression and function of potassium voltage-gated channel subfamily A member 5 (Kv1.5) in PASMC s was inhibited, and pulmonary artery hypertension was exaggerated after chronic hypoxia ( CH ) treatment as adults. micro RNA expression was investigated in PASMC s from 12-week-old male IUGR rats with CH by microarray, polymerase chain reaction, and in situ hybridization. The expression levels of Kv1.5 in primary cultured PASMC s and pulmonary artery smooth muscle from IUGR or control rats were evaluated with and without application of an miR-206 inhibitor. Right ventricular systolic pressure, cell proliferation, luciferase reporter assay, and IKv were also calculated. We found increased expression of miR-206 in resistance pulmonary arteries of IUGR rats at 12 weeks compared with newborns. Application of an miR-206 inhibitor in vivo or in vitro increased expression of Kv1.5 α-protein and KCNA 5. Also, decreased right ventricular systolic pressure and cell proliferation were observed in PASMC s from 12-week-old control and IUGR rats after CH , while inhibitor did not significantly affect control and IUGR rats. Conclusions These results suggest that expression of Kv1.5 and 4-aminopyridine (Kv channel special inhibitor)-sensitive Kv current were correlated with the inhibition of miR-206 in PA rings of IUGR - CH rats and cultured IUGR PASMC s exposed to hypoxia. Thus, miR-206 may be a trigger for induction of exaggerated CH-pulmonary artery hypertension of IUGR via Kv1.5.
Collapse
MESH Headings
- Animals
- Rats
- Animals, Newborn
- Cell Proliferation
- Cells, Cultured
- Disease Models, Animal
- Fetal Growth Retardation/metabolism
- Fetal Growth Retardation/pathology
- Gene Expression Regulation, Developmental
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/genetics
- Hypertension, Pulmonary/metabolism
- In Situ Hybridization
- Kv1.5 Potassium Channel/biosynthesis
- Kv1.5 Potassium Channel/genetics
- Microarray Analysis
- MicroRNAs/biosynthesis
- MicroRNAs/genetics
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Pulmonary Artery/metabolism
- Pulmonary Artery/pathology
- Pulmonary Artery/physiopathology
- RNA/genetics
- Vascular Resistance/physiology
Collapse
Affiliation(s)
- Ying Lv
- Department of Pediatric Health Carethe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Linchen Fu
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Ziming Zhang
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Weizhong Gu
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Xiaofei Luo
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Ying Zhong
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Shanshan Xu
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Yu Wang
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Lingling Yan
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Min Li
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| | - Lizhong Du
- Department of Neonatologythe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvincePeople's Republic of China
| |
Collapse
|
19
|
Fan F, Tian H, Geng J, Deng J, Liu Y, Chen C, Zhang S, Zhang Y, Li J, Tian H, Dart AM, Zou Y. Mechanism of Beraprost Effects on Pulmonary Hypertension: Contribution of Cross-Binding to PGE2 Receptor 4 and Modulation of O 2 Sensitive Voltage-Gated K + Channels. Front Pharmacol 2019; 9:1518. [PMID: 30713496 PMCID: PMC6346678 DOI: 10.3389/fphar.2018.01518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/11/2018] [Indexed: 01/23/2023] Open
Abstract
Background: The purpose of this study is to elucidate mechanism(s) by which the orally active PGI2 analog, Beraprost (BPS), ameliorates pulmonary hypertension (PH). Prostaglandins are an important treatment for PH. Mechanisms of their action are not fully elucidated in relation to receptor subtype and effects on O2 sensitive Kv channels. Methods: Distal (3rd order and beyond) pulmonary arteries from chronically hypoxic rats and from humans with established PH were studied. Measurements included pulmonary haemodynamics and histology, vascular reactivity, prostanoid receptor expression and activity of the O2 sensitive Kv channels. Results: Prostacyclin receptor (IP), prostaglandin receptor E3 (EP3) and prostaglandin receptor E4 (EP4) are the main pulmonary artery receptor subtypes in both rat and human pulmonary arteries. Circulating levels of PGI2 and PGE2 were reduced in PH. PH was also associated with reduced receptor expression of IP but not of EP4. The effects on IP expression were overcome with BPS. Dilatory responses in PH to BPS were reduced in the presence of EP4 blockade. Expression and activity of oxygen sensitive Kv channels were reduced in pulmonary artery smooth muscle cell from rats with PH and humans with PAH and were also overcome by administration of BPS. Effects of BPS on oxygen sensitive Kv channels were reduced in the presence of EP4 blockade implicating the EP4 receptor, as well as the IP receptor, in mediating BPS effects. Conclusion: Reduced expression of pulmonary IP receptors and reduced activity of O2 sensitive Kv channels are found in PH in both humans and rats. The orally active prostacyclin analogue, BPS, is able to reverse these changes, partly through binding to the EP4 receptor.
Collapse
Affiliation(s)
- Fenling Fan
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Hua Tian
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Jie Geng
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Jizhao Deng
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Ya Liu
- Department of Respiratory, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Chunyan Chen
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Songlin Zhang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Yushun Zhang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Jie Li
- Department of Gynecology and Obstetrics, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Hongyan Tian
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Anthony M. Dart
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Department of Cardiovascular Medicine, The Alfred Hospital, Melbourne, VIC, Australia
| | - Yuliang Zou
- Department of Gynecology and Obstetrics, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| |
Collapse
|
20
|
Fu LC, Lv Y, Zhong Y, He Q, Liu X, Du LZ. Tyrosine phosphorylation of Kv1.5 is upregulated in intrauterine growth retardation rats with exaggerated pulmonary hypertension. ACTA ACUST UNITED AC 2017; 50:e6237. [PMID: 28902925 PMCID: PMC5597283 DOI: 10.1590/1414-431x20176237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/04/2017] [Indexed: 12/12/2022]
Abstract
Intrauterine growth retardation (IUGR) is associated with the development of adult-onset diseases, including pulmonary hypertension. However, the underlying mechanism of the early nutritional insult that results in pulmonary vascular dysfunction later in life is not fully understood. Here, we investigated the role of tyrosine phosphorylation of voltage-gated potassium channel 1.5 (Kv1.5) in this prenatal event that results in exaggerated adult vascular dysfunction. A rat model of chronic hypoxia (2 weeks of hypoxia at 12 weeks old) following IUGR was used to investigate the physiological and structural effect of intrauterine malnutrition on the pulmonary artery by evaluating pulmonary artery systolic pressure and vascular diameter in male rats. Kv1.5 expression and tyrosine phosphorylation in pulmonary artery smooth muscle cells (PASMCs) were determined. We found that IUGR increased mean pulmonary artery pressure and resulted in thicker pulmonary artery smooth muscle layer in 14-week-old rats after 2 weeks of hypoxia, while no difference was observed in normoxia groups. In the PASMCs of IUGR-hypoxia rats, Kv1.5 mRNA and protein expression decreased while that of tyrosine-phosphorylated Kv1.5 significantly increased. These results demonstrate that IUGR leads to exaggerated chronic hypoxia pulmonary arterial hypertension (CH-PAH) in association with decreased Kv1.5 expression in PASMCs. This phenomenon may be mediated by increased tyrosine phosphorylation of Kv1.5 in PASMCs and it provides new insight into the prevention and treatment of IUGR-related CH-PAH.
Collapse
Affiliation(s)
- L C Fu
- Department of Neonatology, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Y Lv
- Department of Neonatology, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Y Zhong
- Department of Neonatology, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Q He
- Department of Neonatology, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - X Liu
- Department of Neonatology, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - L Z Du
- Department of Neonatology, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| |
Collapse
|
21
|
Grignola JC, Domingo E. Conceptos básicos en circulación pulmonar. REVISTA COLOMBIANA DE CARDIOLOGÍA 2017. [DOI: 10.1016/j.rccar.2017.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Ohanyan V, Yin L, Bardakjian R, Kolz C, Enrick M, Hakobyan T, Luli J, Graham K, Khayata M, Logan S, Kmetz J, Chilian WM. Kv1.3 channels facilitate the connection between metabolism and blood flow in the heart. Microcirculation 2017; 24:10.1111/micc.12334. [PMID: 28504408 PMCID: PMC5433265 DOI: 10.1111/micc.12334] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 10/23/2016] [Accepted: 11/01/2016] [Indexed: 12/17/2022]
Abstract
The connection between metabolism and flow in the heart, metabolic dilation, is essential for cardiac function. We recently found redox-sensitive Kv1.5 channels play a role in coronary metabolic dilation; however, more than one ion channel likely plays a role in this process as animals null for these channels still showed limited coronary metabolic dilation. Accordingly, we examined the role of another Kv1 family channel, the energetically linked Kv1.3 channel, in coronary metabolic dilation. We measured myocardial blood flow (contrast echocardiography) during norepinephrine-induced increases in cardiac work (heart rate x mean arterial pressure) in WT, WT mice given correolide (preferential Kv1.3 antagonist), and Kv1.3-null mice (Kv1.3-/- ). We also measured relaxation of isolated small arteries mounted in a myograph. During increased cardiac work, myocardial blood flow was attenuated in Kv1.3-/- and in correolide-treated mice. In isolated vessels from Kv1.3-/- mice, relaxation to H2 O2 was impaired (vs WT), but responses to adenosine and acetylcholine were equivalent to WT. Correolide reduced dilation to adenosine and acetylcholine in WT and Kv1.3-/- , but had no effect on H2 O2 -dependent dilation in vessels from Kv1.3-/- mice. We conclude that Kv1.3 channels participate in the connection between myocardial blood flow and cardiac metabolism.
Collapse
Affiliation(s)
- Vahagn Ohanyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Liya Yin
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | | | - Christopher Kolz
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Molly Enrick
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Tatevik Hakobyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Jordan Luli
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Kathleen Graham
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | | | - Suzanna Logan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - John Kmetz
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - William M Chilian
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| |
Collapse
|
24
|
Abstract
Pulmonary arterial hypertension (PAH) remains a mysterious killer that, like cancer, is characterized by tremendous complexity. PAH development occurs under sustained and persistent environmental stress, such as inflammation, shear stress, pseudo-hypoxia, and more. After inducing an initial death of the endothelial cells, these environmental stresses contribute with time to the development of hyper-proliferative and apoptotic resistant clone of cells including pulmonary artery smooth muscle cells, fibroblasts, and even pulmonary artery endothelial cells allowing vascular remodeling and PAH development. Molecularly, these cells exhibit many features common to cancer cells offering the opportunity to exploit therapeutic strategies used in cancer to treat PAH. In this review, we outline the signaling pathways and mechanisms described in cancer that drive PAH cells' survival and proliferation and discuss the therapeutic potential of antineoplastic drugs in PAH.
Collapse
Affiliation(s)
- Olivier Boucherat
- Pulmonary Hypertension and Vascular Biology Research Group, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Department of Medicine, Québec, Canada
| | - Geraldine Vitry
- Pulmonary Hypertension and Vascular Biology Research Group, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Department of Medicine, Québec, Canada
| | - Isabelle Trinh
- Pulmonary Hypertension and Vascular Biology Research Group, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Department of Medicine, Québec, Canada
| | - Roxane Paulin
- Pulmonary Hypertension and Vascular Biology Research Group, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Department of Medicine, Québec, Canada
| | - Steeve Provencher
- Pulmonary Hypertension and Vascular Biology Research Group, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Department of Medicine, Québec, Canada
| | - Sebastien Bonnet
- Pulmonary Hypertension and Vascular Biology Research Group, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Department of Medicine, Québec, Canada
| |
Collapse
|
25
|
Heteromeric complexes of aldo-keto reductase auxiliary K Vβ subunits (AKR6A) regulate sarcolemmal localization of K V1.5 in coronary arterial myocytes. Chem Biol Interact 2017; 276:210-217. [PMID: 28342889 DOI: 10.1016/j.cbi.2017.03.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/02/2017] [Accepted: 03/21/2017] [Indexed: 01/20/2023]
Abstract
Redox-sensitive potassium channels consisting of the voltage-gated K+ (KV) channel pore subunit KV1.5 regulate resting membrane potential and thereby contractility of vascular smooth muscle cells. Members of the KV1 family associate with cytosolic auxiliary β subunits, which are members of the aldo-keto reductase (AKR) superfamily (AKR6A subfamily). The Kvβ subunits have been proposed to regulate Kv1 gating via pyridine nucleotide cofactor binding. However, the molecular identity of KVβ subunits that associate with native KV1.5 channels in the vasculature is unknown. Here, we examined mRNA and protein expression of KVβ subunits and tested whether KVβ isoforms interact with KV1.5 channels in murine coronary arteries. We detected KVβ1 (AKR6A3), KVβ2 (AKR6A5) and KVβ3 (AKR6A9) transcripts and KVβ1 and KVβ2 protein in left anterior descending coronary arteries by real time quantitative PCR and Western blot, respectively. In situ proximity ligation assays indicated abundant protein-protein interactions between KV1.5/KVβ1, KV1.5/KVβ2 and KVβ1/β2 in coronary arterial myocytes. Confocal microscopy and membrane fractionation analyses suggest that arterial myocytes from KVβ2-null mice have reduced abundance of sarcolemmal KV1.5. Together, data suggest that in coronary arterial myocytes, KV1.5 channels predominantly associate with KVβ1 and KVβ2 proteins and that KVβ2 performs a chaperone function for KV1.5 channels in arterial myocytes, thereby facilitating Kv1α trafficking and membrane localization.
Collapse
|
26
|
Molecular targets of the Warburg effect and inflammatory cytokines in the pathogenesis of pulmonary artery hypertension. Clin Chim Acta 2017; 466:98-104. [DOI: 10.1016/j.cca.2017.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/09/2017] [Accepted: 01/12/2017] [Indexed: 02/01/2023]
|
27
|
Song T, Zheng YM, Wang YX. Cross Talk Between Mitochondrial Reactive Oxygen Species and Sarcoplasmic Reticulum Calcium in Pulmonary Arterial Smooth Muscle Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 967:289-298. [DOI: 10.1007/978-3-319-63245-2_17] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
28
|
Dunham-Snary KJ, Wu D, Sykes EA, Thakrar A, Parlow LRG, Mewburn JD, Parlow JL, Archer SL. Hypoxic Pulmonary Vasoconstriction: From Molecular Mechanisms to Medicine. Chest 2017; 151:181-192. [PMID: 27645688 PMCID: PMC5310129 DOI: 10.1016/j.chest.2016.09.001] [Citation(s) in RCA: 262] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 09/01/2016] [Accepted: 09/02/2016] [Indexed: 12/11/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a homeostatic mechanism that is intrinsic to the pulmonary vasculature. Intrapulmonary arteries constrict in response to alveolar hypoxia, diverting blood to better-oxygenated lung segments, thereby optimizing ventilation/perfusion matching and systemic oxygen delivery. In response to alveolar hypoxia, a mitochondrial sensor dynamically changes reactive oxygen species and redox couples in pulmonary artery smooth muscle cells (PASMC). This inhibits potassium channels, depolarizes PASMC, activates voltage-gated calcium channels, and increases cytosolic calcium, causing vasoconstriction. Sustained hypoxia activates rho kinase, reinforcing vasoconstriction, and hypoxia-inducible factor (HIF)-1α, leading to adverse pulmonary vascular remodeling and pulmonary hypertension (PH). In the nonventilated fetal lung, HPV diverts blood to the systemic vasculature. After birth, HPV commonly occurs as a localized homeostatic response to focal pneumonia or atelectasis, which optimizes systemic Po2 without altering pulmonary artery pressure (PAP). In single-lung anesthesia, HPV reduces blood flow to the nonventilated lung, thereby facilitating thoracic surgery. At altitude, global hypoxia causes diffuse HPV, increases PAP, and initiates PH. Exaggerated or heterogeneous HPV contributes to high-altitude pulmonary edema. Conversely, impaired HPV, whether due to disease (eg, COPD, sepsis) or vasodilator drugs, promotes systemic hypoxemia. Genetic and epigenetic abnormalities of this oxygen-sensing pathway can trigger normoxic activation of HIF-1α and can promote abnormal metabolism and cell proliferation. The resulting pseudohypoxic state underlies the Warburg metabolic shift and contributes to the neoplasia-like phenotype of PH. HPV and oxygen sensing are important in human health and disease.
Collapse
Affiliation(s)
| | - Danchen Wu
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Edward A Sykes
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Amar Thakrar
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Leah R G Parlow
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | | | - Joel L Parlow
- Department of Anesthesiology and Perioperative Medicine, Queen's University, Kingston, ON, Canada
| | - Stephen L Archer
- Department of Medicine, Queen's University, Kingston, ON, Canada.
| |
Collapse
|
29
|
Hayabuchi Y. The Action of Smooth Muscle Cell Potassium Channels in the Pathology of Pulmonary Arterial Hypertension. Pediatr Cardiol 2017; 38:1-14. [PMID: 27826710 DOI: 10.1007/s00246-016-1491-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 10/25/2016] [Indexed: 01/05/2023]
Abstract
Many different types of potassium channels with various functions exist in pulmonary artery smooth muscle cells, contributing to many physiological actions and pathological conditions. The deep involvement of these channels in the onset and exacerbation of pulmonary arterial hypertension (PAH) also continues to be revealed. In 2013, KCNK3 (TASK1), which encodes a type of two-pore domain potassium channel, was shown to be a predisposing gene for PAH by genetic mutation, and it was added to the PAH classification at the Fifth World Symposium on Pulmonary Hypertension (Nice International Conference). Decreased expression and inhibited activity of voltage-gated potassium channels, particularly KCNA5 (Kv1.5), are also seen in PAH, regardless of the cause, and facilitation of pulmonary arterial contraction and vascular remodeling has been shown. The calcium-activated potassium channels seen in smooth muscle cells also change from BKca (Kca1.1) to IKca (Kca3.1) predominance in PAH due to transformation and have effects including the facilitation of smooth muscle cell migration, enhancement of proliferation, and inhibition of apoptosis. Elucidation of these roles for potassium channels in pulmonary vasoconstriction and remodeling may help bring new therapeutic strategies into view.
Collapse
Affiliation(s)
- Yasunobu Hayabuchi
- Department of Pediatrics, Tokushima University, Kuramoto-cho-3, Tokushima, 770-8503, Japan.
| |
Collapse
|
30
|
Wen W, Yan L, Dunquan X. Role of ROS/Kv/HIF Axis in the Development of Hypoxia-Induced Pulmonary Hypertension. ACTA ACUST UNITED AC 2017; 32:253-259. [DOI: 10.24920/j1001-9294.2017.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
31
|
Brinks L, Moonen RMJ, Moral-Sanz J, Barreira B, Kessels L, Perez-Vizcaino F, Cogolludo A, Villamor E. Hypoxia-induced contraction of chicken embryo mesenteric arteries: mechanisms and developmental changes. Am J Physiol Regul Integr Comp Physiol 2016; 311:R858-R869. [DOI: 10.1152/ajpregu.00461.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 08/10/2016] [Indexed: 11/22/2022]
Abstract
The fetal cardiovascular responses to acute hypoxia include a redistribution of the cardiac output toward the heart and the brain at the expense of other organs, such as the intestine. We hypothesized that hypoxia exerts a direct effect on the mesenteric artery (MA) that may contribute to this response. Using wire myography, we investigated the response to hypoxia (Po2 ~2.5 kPa for 20 min) of isolated MAs from 15- to 21-day chicken embryos (E15, E19, E21), and 1- to 45-day-old chickens (P1, P3, P14, P45). Agonist-induced pretone or an intact endothelium were not required to obtain a consistent and reproducible response to hypoxia, which showed a pattern of initial rapid phasic contraction followed by a sustained tonic contraction. Phasic contraction was reduced by elimination of extracellular Ca2+ or by presence of the neurotoxin tetrodotoxin, the α1-adrenoceptor antagonist prazosin, or inhibitors of L-type voltage-gated Ca2+ channels (nifedipine), mitochondrial electron transport chain (rotenone and antimycin A), and NADPH oxidase (VAS2870). The Rho-kinase inhibitor Y27632 impaired both phasic and tonic contraction and, when combined with elimination of extracellular Ca2+, hypoxia-induced contraction was virtually abolished. Hypoxic MA contraction was absent at E15 but present from E19 and increased toward the first days posthatching. It then decreased during the first weeks of life and P45 MAs were unable to sustain hypoxia-induced contraction over time. In conclusion, the results of the present study demonstrate that hypoxic vasoconstriction is an intrinsic feature of chicken MA vascular smooth muscle cells during late embryogenesis and the perinatal period.
Collapse
Affiliation(s)
- Leonie Brinks
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
| | - Rob M. J. Moonen
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
- Department of Pediatrics, Zuyderland Medical Center, Heerlen, The Netherlands; and
| | - Javier Moral-Sanz
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Bianca Barreira
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Lilian Kessels
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
| | - Francisco Perez-Vizcaino
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Angel Cogolludo
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Eduardo Villamor
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
| |
Collapse
|
32
|
Kim HJ, Yoo HY. Hypoxic pulmonary vasoconstriction and vascular contractility in monocrotaline-induced pulmonary arterial hypertensive rats. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 20:641-647. [PMID: 27847441 PMCID: PMC5106398 DOI: 10.4196/kjpp.2016.20.6.641] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 08/26/2016] [Accepted: 08/29/2016] [Indexed: 02/04/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a progressive disease characterized by vascular remodeling of pulmonary arteries (PAs) and increased vascular resistance in the lung. Monocrotaline (MCT), a toxic alkaloid, is widely used for developing rat models of PAH caused by injury to pulmonary endothelial cells; however, characteristics of vascular functions in MCT-induced PAH vary and are not fully understood. Here, we investigated hypoxic pulmonary vasoconstriction (HPV) responses and effects of various vasoconstrictors with isolated/perfused lungs of MCT-induced PAH (PAH-MCT) rats. Using hematoxylin and eosin staining, we confirmed vascular remodeling (i.e., medial thickening of PA) and right ventricle hypertrophy in PAH-MCT rats. The basal pulmonary arterial pressure (PAP) and PAP increase by a raised flow rate (40 mL/min) were higher in the PAH-MCT than in the control rats. In addition, both high K+ (40 mM KCl)- and angiotensin II-induced PAP increases were higher in the PAH-MCT than in the control rats. Surprisingly, application of a nitric oxide synthase inhibitor, L-NG-Nitroarginine methyl ester (L-NAME), induced a marked PAP increase in the PAH-MCT rats, suggesting that endothelial functions were recovered in the three-week PAH-MCT rats. In addition, the medial thickening of the PA was similar to that in chronic hypoxia-induced PAH (PAH-CH) rats. However, the HPV response (i.e., PAP increased by acute hypoxia) was not affected in the MCT rats, whereas HPV disappeared in the PAH-CH rats. These results showed that vascular contractility and HPV remain robust in the MCT-induced PAH rat model with vascular remodeling.
Collapse
Affiliation(s)
- Hae Jin Kim
- Department of Physiology, Department of Biomedical Sciences and Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Hae Young Yoo
- Chung-Ang University Red Cross College of Nursing, Seoul 06974, Korea
| |
Collapse
|
33
|
Moral-Sanz J, Mahmoud AD, Ross FA, Eldstrom J, Fedida D, Hardie DG, Evans AM. AMP-activated protein kinase inhibits Kv 1.5 channel currents of pulmonary arterial myocytes in response to hypoxia and inhibition of mitochondrial oxidative phosphorylation. J Physiol 2016; 594:4901-15. [PMID: 27062501 PMCID: PMC5009768 DOI: 10.1113/jp272032] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/26/2016] [Indexed: 12/29/2022] Open
Abstract
KEY POINTS Progression of hypoxic pulmonary hypertension is thought to be due, in part, to suppression of voltage-gated potassium channels (Kv ) in pulmonary arterial smooth muscle by hypoxia, although the precise molecular mechanisms have been unclear. AMP-activated protein kinase (AMPK) has been proposed to couple inhibition of mitochondrial metabolism by hypoxia to acute hypoxic pulmonary vasoconstriction and progression of pulmonary hypertension. Inhibition of complex I of the mitochondrial electron transport chain activated AMPK and inhibited Kv 1.5 channels in pulmonary arterial myocytes. AMPK activation by 5-aminoimidazole-4-carboxamide riboside, A769662 or C13 attenuated Kv 1.5 currents in pulmonary arterial myocytes, and this effect was non-additive with respect to Kv 1.5 inhibition by hypoxia and mitochondrial poisons. Recombinant AMPK phosphorylated recombinant human Kv 1.5 channels in cell-free assays, and inhibited K(+) currents when introduced into HEK 293 cells stably expressing Kv 1.5. These results suggest that AMPK is the primary mediator of reductions in Kv 1.5 channels following inhibition of mitochondrial oxidative phosphorylation during hypoxia and by mitochondrial poisons. ABSTRACT Progression of hypoxic pulmonary hypertension is thought to be due, in part, to suppression of voltage-gated potassium channels (Kv ) in pulmonary arterial smooth muscle cells that is mediated by the inhibition of mitochondrial oxidative phosphorylation. We sought to determine the role in this process of the AMP-activated protein kinase (AMPK), which is intimately coupled to mitochondrial function due to its activation by LKB1-dependent phosphorylation in response to increases in the cellular AMP:ATP and/or ADP:ATP ratios. Inhibition of complex I of the mitochondrial electron transport chain using phenformin activated AMPK and inhibited Kv currents in pulmonary arterial myocytes, consistent with previously reported effects of mitochondrial inhibitors. Myocyte Kv currents were also markedly inhibited upon AMPK activation by A769662, 5-aminoimidazole-4-carboxamide riboside and C13 and by intracellular dialysis from a patch-pipette of activated (thiophosphorylated) recombinant AMPK heterotrimers (α2β2γ1 or α1β1γ1). Hypoxia and inhibitors of mitochondrial oxidative phosphorylation reduced AMPK-sensitive K(+) currents, which were also blocked by the selective Kv 1.5 channel inhibitor diphenyl phosphine oxide-1 but unaffected by the presence of the BKCa channel blocker paxilline. Moreover, recombinant human Kv 1.5 channels were phosphorylated by AMPK in cell-free assays, and K(+) currents carried by Kv 1.5 stably expressed in HEK 293 cells were inhibited by intracellular dialysis of AMPK heterotrimers and by A769662, the effects of which were blocked by compound C. We conclude that AMPK mediates Kv channel inhibition by hypoxia in pulmonary arterial myocytes, at least in part, through phosphorylation of Kv 1.5 and/or an associated protein.
Collapse
Affiliation(s)
- Javier Moral-Sanz
- Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Amira D Mahmoud
- Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Fiona A Ross
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Jodene Eldstrom
- Department of Anaesthesiology. Pharmacology and Therapeutics, University of British Columbia, 2350 Health Science Mall, Vancouver, Canada, V6T 1Z3
| | - David Fedida
- Department of Anaesthesiology. Pharmacology and Therapeutics, University of British Columbia, 2350 Health Science Mall, Vancouver, Canada, V6T 1Z3
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - A Mark Evans
- Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, EH8 9XD, UK
| |
Collapse
|
34
|
Arsyad A, Dobson GP. Adenosine relaxation in isolated rat aortic rings and possible roles of smooth muscle Kv channels, KATP channels and A2a receptors. BMC Pharmacol Toxicol 2016; 17:23. [PMID: 27211886 PMCID: PMC4876563 DOI: 10.1186/s40360-016-0067-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/29/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND An area of ongoing controversy is the role adenosine to regulate vascular tone in conduit vessels that regulate compliance, and the role of nitric oxide (NO), potassium channels and receptor subtypes involved. The aim of our study was to investigate adenosine relaxation in rat thoracic aortic rings, and the effect of inhibitors of NO, prostanoids, Kv, KATP channels, and A2a and A2b receptors. METHODS Aortic rings were freshly harvested from adult male Sprague Dawley rats and equilibrated in an organ bath containing oxygenated, modified Krebs-Henseleit solution, 11 mM glucose, pH 7.4, 37 °C. Isolated rings were pre-contracted sub-maximally with 0.3 μM norepinephrine (NE), and the effect of increasing concentrations of adenosine (1 to 1000 μM) were examined. The drugs L-NAME, indomethacin, 4-aminopyridine (4-AP), glibenclamide, 5-hydroxydecanoate, ouabain, 8-(3-chlorostyryl) caffeine and PSB-0788 were examined in intact and denuded rings. Rings were tested for viability after each experiment. RESULTS Adenosine induced a dose-dependent, triphasic relaxation response, and the mechanical removal of the endothelium significantly deceased adenosine relaxation above 10 μM. Interestingly, endothelial removal significantly decreased the responsiveness (defined as % relaxation per μM adenosine) by two-thirds between 10 and 100 μM, but not in the lower (1-10 μM) or higher (>100 μM) ranges. In intact rings, L-NAME significantly reduced relaxation, but not indomethacin. Antagonists of voltage-dependent Kv (4-AP), sarcolemma KATP (glibenclamide) and mitochondrial KATP channels (5-HD) led to significant reductions in relaxation in both intact and denuded rings, with ouabain having little or no effect. Adenosine-induced relaxation appeared to involve the A2a receptor, but not the A2b subtype. CONCLUSIONS It was concluded that adenosine relaxation in NE-precontracted rat aortic rings was triphasic and endothelium-dependent above 10 μM, and relaxation involved endothelial nitric oxide (not prostanoids) and a complex interplay between smooth muscle A2a subtype and voltage-dependent Kv, SarcKATP and MitoKATP channels. The possible in vivo significance of the regulation of arterial compliance to left ventricular function coupling is discussed.
Collapse
Affiliation(s)
- Aryadi Arsyad
- Physiology Department, Medical Faculty, Hasanuddin University, Jl. Perintis Kemerdekaan, Km. 10, Tamalanrea, Makassar, 90213, Indonesia
| | - Geoffrey P Dobson
- Heart, Trauma and Sepsis Research Laboratory, Australian Institute of Tropical Health and Medicine, College of Medicine and Dentistry, James Cook University, 1 James Cook Drive, Queensland, 4811, Australia.
| |
Collapse
|
35
|
Bocksteins E. Kv5, Kv6, Kv8, and Kv9 subunits: No simple silent bystanders. J Gen Physiol 2016; 147:105-25. [PMID: 26755771 PMCID: PMC4727947 DOI: 10.1085/jgp.201511507] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/11/2015] [Indexed: 12/19/2022] Open
Abstract
Members of the electrically silent voltage-gated K(+) (Kv) subfamilies (Kv5, Kv6, Kv8, and Kv9, collectively identified as electrically silent voltage-gated K(+) channel [KvS] subunits) do not form functional homotetrameric channels but assemble with Kv2 subunits into heterotetrameric Kv2/KvS channels with unique biophysical properties. Unlike the ubiquitously expressed Kv2 subunits, KvS subunits show a more restricted expression. This raises the possibility that Kv2/KvS heterotetramers have tissue-specific functions, making them potential targets for the development of novel therapeutic strategies. Here, I provide an overview of the expression of KvS subunits in different tissues and discuss their proposed role in various physiological and pathophysiological processes. This overview demonstrates the importance of KvS subunits and Kv2/KvS heterotetramers in vivo and the importance of considering KvS subunits and Kv2/KvS heterotetramers in the development of novel treatments.
Collapse
Affiliation(s)
- Elke Bocksteins
- Laboratory for Molecular Biophysics, Physiology, and Pharmacology, Department for Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium
| |
Collapse
|
36
|
Archer SL. Acquired Mitochondrial Abnormalities, Including Epigenetic Inhibition of Superoxide Dismutase 2, in Pulmonary Hypertension and Cancer: Therapeutic Implications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:29-53. [PMID: 27343087 DOI: 10.1007/978-1-4899-7678-9_3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There is no cure for non-small-cell lung cancer (NSCLC) or pulmonary arterial hypertension (PAH). Therapies lack efficacy and/or are toxic, reflecting a failure to target disease abnormalities that are distinct from processes vital to normal cells. NSCLC and PAH share reversible mitochondrial-metabolic abnormalities which may offer selective therapeutic targets. The following mutually reinforcing, mitochondrial abnormalities favor proliferation, impair apoptosis, and are relatively restricted to PAH and cancer cells: (1) Epigenetic silencing of superoxide dismutase-2 (SOD2) by methylation of CpG islands creates a pseudohypoxic redox environment that causes normoxic activation of hypoxia inducible factor (HIF-1α). (2) HIF-1α increases expression of pyruvate dehydrogenase kinase (PDK), which impairs oxidative metabolism and promotes a glycolytic metabolic state. (3) Mitochondrial fragmentation, partially due to mitofusin-2 downregulation, promotes proliferation. This review focuses on the recent discovery that decreased expression of SOD2, a putative tumor-suppressor gene and the major source of H2O2, results from hypermethylation of CpG islands. In cancer and PAH hypermethylation of a site in the enhancer region of intron 2 inhibits SOD2 transcription. In normal PASMC, SOD2 siRNA decreases H2O2 and activates HIF-1α. In PAH, reduced SOD2 expression decreases H2O2, reduces the cytosol and thereby activates HIF-1α. This causes a glycolytic shift in metabolism and increases the proliferation/apoptosis ratio by downregulating Kv1.5 channels, increasing cytosolic calcium, and inhibiting caspases. The DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine, which restores SOD2 expression, corrects the proliferation/apoptosis imbalance in PAH and cancer cells. The specificity of PAH for lung vessels may relate to the selective upregulation of DNA methyltransferases that mediate CpG methylation in PASMC (DNA MT-1A and -3B). SOD2 augmentation inactivates HIF-1α in PAH PASMC and therapy with the SOD mimetic, MnTBAP, regresses experimental PAH. In conclusion, cancer and PAH share acquired mitochondrial abnormalities that increase proliferation and inhibit apoptosis, suggesting new therapeutic targets.
Collapse
Affiliation(s)
- Stephen L Archer
- Head Department of Medicine, Queen's University Program Medical Director KGH, HD, SMOL Etherington Hall, Room 3041 94 Stuart St., Kingston, Ontario, Canada, K7L 3N6.
| |
Collapse
|
37
|
Jahn N, Lamberts RR, Busch CJ, Voelker MT, Busch T, Koel-Simmelink MJA, Teunissen CE, Oswald DD, Loer SA, Kaisers UX, Weimann J. Inhaled carbon monoxide protects time-dependently from loss of hypoxic pulmonary vasoconstriction in endotoxemic mice. Respir Res 2015; 16:119. [PMID: 26415503 PMCID: PMC4587582 DOI: 10.1186/s12931-015-0274-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 09/07/2015] [Indexed: 11/30/2022] Open
Abstract
Background Inhaled carbon monoxide (CO) appears to have beneficial effects on endotoxemia-induced impairment of hypoxic pulmonary vasoconstriction (HPV). This study aims to specify correct timing of CO application, it’s biochemical mechanisms and effects on inflammatory reactions. Methods Mice (C57BL/6; n = 86) received lipopolysaccharide (LPS, 30 mg/kg) intraperitoneally and subsequently breathed 50 ppm CO continuously during defined intervals of 3, 6, 12 or 18 h. Two control groups received saline intraperitoneally and additionally either air or CO, and one control group received LPS but breathed air only. In an isolated lung perfusion model vasoconstrictor response to hypoxia (FiO2 = 0.01) was quantified by measurements of pulmonary artery pressure. Pulmonary capillary pressure was estimated by double occlusion technique. Further, inflammatory plasma cytokines and lung tissue mRNA of nitric-oxide-synthase-2 (NOS-2) and heme oxygenase-1 (HO-1) were measured. Results HPV was impaired after LPS-challenge (p < 0.01). CO exposure restored HPV-responsiveness if administered continuously for full 18 h, for the first 6 h and if given in the interval between the 3rd and 6th hour after LPS-challenge (p < 0.05). Preserved HPV was attributable to recovered arterial resistance and associated with significant reduction in NOS-2 mRNA when compared to controls (p < 0.05). We found no effects on inflammatory plasma cytokines. Conclusion Low-dose CO prevented LPS-induced impairment of HPV in a time-dependent manner, associated with a decreased NOS-2 expression.
Collapse
Affiliation(s)
- Nora Jahn
- Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany.
| | - Regis R Lamberts
- Department of Anaesthesiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Centre, Amsterdam, The Netherlands.
| | - Cornelius J Busch
- Department of Anaesthesiology, Ruprecht-Karls-University, Heidelberg, Germany.
| | - Maria T Voelker
- Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany.
| | - Thilo Busch
- Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany.
| | - Marleen J A Koel-Simmelink
- Department of Clinical Chemistry, Neurological Laboratory and Biobank, VU University Medical Centre, Amsterdam, The Netherlands.
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, Neurological Laboratory and Biobank, VU University Medical Centre, Amsterdam, The Netherlands.
| | - Daniel D Oswald
- Department of Anaesthesiology, Universitätsklinikum, Münster, Germany.
| | - Stephan A Loer
- Department of Anaesthesiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Centre, Amsterdam, The Netherlands.
| | - Udo X Kaisers
- Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany.
| | - Jörg Weimann
- Department of Anaesthesia and Intensive Care Medicine, Sankt Gertrauden-Krankenhaus, Berlin, Germany.
| |
Collapse
|
38
|
Dunham-Snary KJ, Hong ZG, Xiong PY, Del Paggio JC, Herr JE, Johri AM, Archer SL. A mitochondrial redox oxygen sensor in the pulmonary vasculature and ductus arteriosus. Pflugers Arch 2015; 468:43-58. [PMID: 26395471 DOI: 10.1007/s00424-015-1736-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/09/2015] [Accepted: 09/15/2015] [Indexed: 12/18/2022]
Abstract
The mammalian homeostatic oxygen sensing system (HOSS) initiates changes in vascular tone, respiration, and neurosecretion that optimize oxygen uptake and tissue oxygen delivery within seconds of detecting altered environmental or arterial PO2. The HOSS includes carotid body type 1 cells, adrenomedullary cells, neuroepithelial bodies, and smooth muscle cells (SMCs) in pulmonary arteries (PAs), ductus arteriosus (DA), and fetoplacental arteries. Hypoxic pulmonary vasoconstriction (HPV) optimizes ventilation-perfusion matching. In utero, HPV diverts placentally oxygenated blood from the non-ventilated lung through the DA. At birth, increased alveolar and arterial oxygen tension dilates the pulmonary vasculature and constricts the DA, respectively, thereby transitioning the newborn to an air-breathing organism. Though modulated by endothelial-derived relaxing and constricting factors, O2 sensing is intrinsic to PASMCs and DASMCs. Within the SMC's dynamic mitochondrial network, changes in PO2 alter the reduction-oxidation state of redox couples (NAD(+)/NADH, NADP(+)/NADPH) and the production of reactive oxygen species, ROS (e.g., H2O2), by complexes I and III of the electron transport chain (ETC). ROS and redox couples regulate ion channels, transporters, and enzymes, changing intracellular calcium [Ca(2+)]i and calcium sensitivity and eliciting homeostatic responses to hypoxia. In PASMCs, hypoxia inhibits ROS production and reduces redox couples, thereby inhibiting O2-sensitive voltage-gated potassium (Kv) channels, depolarizing the plasma membrane, activating voltage-gated calcium channels (CaL), increasing [Ca(2+)]i, and causing vasoconstriction. In DASMCs, elevated PO2 causes mitochondrial fission, increasing ETC complex I activity and ROS production. The DASMC's downstream response to elevated PO2 (Kv channel inhibition, CaL activation, increased [Ca(2+)]i, and rho kinase activation) is similar to the PASMC's hypoxic response. Impaired O2 sensing contributes to human diseases, including pulmonary arterial hypertension and patent DA.
Collapse
Affiliation(s)
- Kimberly J Dunham-Snary
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada
| | - Zhigang G Hong
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada
| | - Ping Y Xiong
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada
| | - Joseph C Del Paggio
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada
| | - Julia E Herr
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada
| | - Amer M Johri
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada
| | - Stephen L Archer
- Department of Medicine, Queen's University, Etherington Hall, Room 3041, 94 Stuart St, Kingston, ON, K7L 3N6, Canada.
| |
Collapse
|
39
|
Boucherat O, Chabot S, Antigny F, Perros F, Provencher S, Bonnet S. Potassium channels in pulmonary arterial hypertension. Eur Respir J 2015; 46:1167-77. [PMID: 26341985 DOI: 10.1183/13993003.00798-2015] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/09/2015] [Indexed: 12/15/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a devastating cardiopulmonary disorder with various origins. All forms of PAH share a common pulmonary arteriopathy characterised by vasoconstriction, remodelling of the pre-capillary pulmonary vessel wall, and in situ thrombosis. Although the pathogenesis of PAH is recognised as a complex and multifactorial process, there is growing evidence that potassium channels dysfunction in pulmonary artery smooth muscle cells is a hallmark of PAH. Besides regulating many physiological functions, reduced potassium channels expression and/or activity have significant effects on PAH establishment and progression. This review describes the molecular mechanisms and physiological consequences of potassium channel modulation. Special emphasis is placed on KCNA5 (Kv1.5) and KCNK3 (TASK1), which are considered to play a central role in determining pulmonary vascular tone and may represent attractive therapeutic targets in the treatment of PAH.
Collapse
Affiliation(s)
- Olivier Boucherat
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Sophie Chabot
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Fabrice Antigny
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada UMRS 999, INSERM and Univ. Paris-Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France
| | - Frédéric Perros
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada UMRS 999, INSERM and Univ. Paris-Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France
| | - Steeve Provencher
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Sébastien Bonnet
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| |
Collapse
|
40
|
Ohanyan V, Yin L, Bardakjian R, Kolz C, Enrick M, Hakobyan T, Kmetz J, Bratz I, Luli J, Nagane M, Khan N, Hou H, Kuppusamy P, Graham J, Fu FK, Janota D, Oyewumi MO, Logan S, Lindner JR, Chilian WM. Requisite Role of Kv1.5 Channels in Coronary Metabolic Dilation. Circ Res 2015. [PMID: 26224794 DOI: 10.1161/circresaha.115.306642] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
RATIONALE In the working heart, coronary blood flow is linked to the production of metabolites, which modulate tone of smooth muscle in a redox-dependent manner. Voltage-gated potassium channels (Kv), which play a role in controlling membrane potential in vascular smooth muscle, have certain members that are redox-sensitive. OBJECTIVE To determine the role of redox-sensitive Kv1.5 channels in coronary metabolic flow regulation. METHODS AND RESULTS In mice (wild-type [WT], Kv1.5 null [Kv1.5(-/-)], and Kv1.5(-/-) and WT with inducible, smooth muscle-specific expression of Kv1.5 channels), we measured mean arterial pressure, myocardial blood flow, myocardial tissue oxygen tension, and ejection fraction before and after inducing cardiac stress with norepinephrine. Cardiac work was estimated as the product of mean arterial pressure and heart rate. Isolated arteries were studied to establish whether genetic alterations modified vascular reactivity. Despite higher levels of cardiac work in the Kv1.5(-/-) mice (versus WT mice at baseline and all doses of norepinephrine), myocardial blood flow was lower in Kv1.5(-/-) mice than in WT mice. At high levels of cardiac work, tissue oxygen tension dropped significantly along with ejection fraction. Expression of Kv1.5 channels in smooth muscle in the null background rescued this phenotype of impaired metabolic dilation. In isolated vessels from Kv1.5(-/-) mice, relaxation to H2O2 was impaired, but responses to adenosine and acetylcholine were normal compared with those from WT mice. CONCLUSIONS Kv1.5 channels in vascular smooth muscle play a critical role in coupling myocardial blood flow to cardiac metabolism. Absence of these channels disassociates metabolism from flow, resulting in cardiac pump dysfunction and tissue hypoxia.
Collapse
Affiliation(s)
| | - Liya Yin
- Department of Integrative Medical Sciences
| | - Raffi Bardakjian
- Departement Internal Medicine, Canton Medical Education Foundation
| | | | | | | | - John Kmetz
- Department of Integrative Medical Sciences
| | - Ian Bratz
- Department of Integrative Medical Sciences
| | | | - Masaki Nagane
- Department of Radiology and Medicine, Geisel School of Medicine at Dartmouth College
| | - Nadeem Khan
- Department of Radiology and Medicine, Geisel School of Medicine at Dartmouth College
| | - Huagang Hou
- Department of Radiology and Medicine, Geisel School of Medicine at Dartmouth College
| | - Periannan Kuppusamy
- Department of Radiology and Medicine, Geisel School of Medicine at Dartmouth College
| | | | | | | | - Moses O Oyewumi
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University
| | | | - Jonathan R Lindner
- Division of Cardiovascular Medicine, UHN62, Oregon Health and Science University
| | | |
Collapse
|
41
|
Ma H, Xu D, Wu Y, Ma Y, Li Z. To decipher the hypoxic pulmonary hypertension: Vascular heterogeneity and the hypothesis of hypoxic responsive threshold. JOURNAL OF MEDICAL HYPOTHESES AND IDEAS 2015. [DOI: 10.1016/j.jmhi.2015.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
42
|
Zheng L, Liu M, Wei M, Liu Y, Dong M, Luo Y, Zhao P, Dong H, Niu W, Yan Z, Li Z. Tanshinone IIA attenuates hypoxic pulmonary hypertension via modulating KV currents. Respir Physiol Neurobiol 2015; 205:120-8. [DOI: 10.1016/j.resp.2014.09.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/22/2014] [Accepted: 09/30/2014] [Indexed: 01/10/2023]
|
43
|
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.
Collapse
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
| |
Collapse
|
44
|
Shin DH, Lin H, Zheng H, Kim KS, Kim JY, Chun YS, Park JW, Nam JH, Kim WK, Zhang YH, Kim SJ. HIF-1α-mediated upregulation of TASK-2 K⁺ channels augments Ca²⁺ signaling in mouse B cells under hypoxia. THE JOURNAL OF IMMUNOLOGY 2014; 193:4924-33. [PMID: 25305321 DOI: 10.4049/jimmunol.1301829] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The general consensus is that immune cells are exposed to physiological hypoxia in vivo (PhyO2, 2-5% P(O2)). However, functional studies of B cells in hypoxic conditions are sparse. Recently, we reported the expression in mouse B cells of TASK-2, a member of pH-sensitive two-pore domain K(+) channels with background activity. In this study, we investigated the response of K(+) channels to sustained PhyO2 (sustained hypoxia [SH], 3% P(O2) for 24 h) in WEHI-231 mouse B cells. SH induced voltage-independent background K(+) conductance (SH-K(bg)) and hyperpolarized the membrane potential. The pH sensitivity and the single-channel conductance of SH-K(bg) were consistent with those of TASK-2. Immunoblotting assay results showed that SH significantly increased plasma membrane expressions of TASK-2. Conversely, SH failed to induce any current following small interfering (si)TASK-2 transfection. Similar hypoxic upregulation of TASK-2 was also observed in splenic primary B cells. Mechanistically, upregulation of TASK-2 by SH was prevented by si hypoxia-inducible factor-1α (HIF-1α) transfection or by YC-1, a pharmacological HIF-1α inhibitor. In addition, TASK-2 current was increased in WEHI-231 cells overexpressed with O2-resistant HIF-1α. Importantly, [Ca(2+)]c increment in response to BCR stimulation was significantly higher in SH-exposed B cells, which was abolished by high K(+)-induced depolarization or by siTASK-2 transfection. The data demonstrate that TASK-2 is upregulated under hypoxia via HIF-1α-dependent manner in B cells. This is functionally important in maintaining the negative membrane potential and providing electrical driving force to control Ca(2+) influx.
Collapse
Affiliation(s)
- Dong Hoon Shin
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Division of Natural Medical Sciences, College of Health Science, Chosun University, Gwangju 501-759, Republic of Korea
| | - Haiyue Lin
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Haifeng Zheng
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Kyung Su Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Jin Young Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Yang Sook Chun
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Jong Wan Park
- Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; and
| | - Joo Hyun Nam
- Channelopathy Research Center, Dongguk University College of Medicine, Goyang 410-773, Republic of Korea
| | - Woo Kyung Kim
- Channelopathy Research Center, Dongguk University College of Medicine, Goyang 410-773, Republic of Korea
| | - Yin Hua Zhang
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea;
| |
Collapse
|
45
|
Pandit LM, Lloyd EE, Reynolds JO, Lawrence WS, Reynolds C, Wehrens XHT, Bryan RM. TWIK-2 channel deficiency leads to pulmonary hypertension through a rho-kinase-mediated process. Hypertension 2014; 64:1260-5. [PMID: 25245387 DOI: 10.1161/hypertensionaha.114.03406] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
TWIK-2 (KCNK6) is a member of the 2-pore domain (K2P) family of potassium channels, which are highly expressed in the vascular system. We tested the hypothesis that TWIK-2 deficiency leads to pulmonary hypertension. TWIK-2 knockout mice and their wildtype littermates at 8 weeks of age had similar mean right ventricular systolic pressures (24±3 and 21±3 mm Hg, respectively.) Significantly, by 20 weeks of age, the mean right ventricular systolic pressures in TWIK-2 knockout mice increased to 35±3 mm Hg (P≤0.036), whereas mean right ventricular systolic pressures in wildtype littermates remained at 22±3 mm Hg. Elevated mean right ventricular systolic pressures in the TWIK-2 knockout mice was accompanied by pulmonary vascular remodeling as determined by a 25% increase in the cross-sectional area of the vessels occupied by the vessel wall. Additionally, secondary branches of the pulmonary artery from 20-week-old TWIK-2 knockout mice showed an enhanced contractile response to U46619 (10(-6) moles/L), a thromboxane A2 mimetic, which was completely abolished with the Rho-kinase inhibitor, Y27632 (10(-6) and 10(-5) moles/L). Treatment of TWIK-2 knockout mice with the Rho-kinase inhibitor, fasudil, in the drinking water for 12 weeks, abolished the development of pulmonary hypertension and attenuated the vessel remodeling. We concluded that mice deficient in the TWIK-2 channel develop pulmonary hypertension between 8 and 20 weeks of age through a mechanism involving Rho-kinase. Our results suggest that downregulation of TWIK-2 in the pulmonary vasculature may be an underlying mechanism in the development of pulmonary hypertension.
Collapse
Affiliation(s)
- Lavannya M Pandit
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Eric E Lloyd
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Julia O Reynolds
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - William S Lawrence
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Corey Reynolds
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Xander H T Wehrens
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Robert M Bryan
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| |
Collapse
|
46
|
Ramiro-Diaz JM, Giermakowska W, Weaver JM, Jernigan NL, Gonzalez Bosc LV. Mechanisms of NFATc3 activation by increased superoxide and reduced hydrogen peroxide in pulmonary arterial smooth muscle. Am J Physiol Cell Physiol 2014; 307:C928-38. [PMID: 25163518 DOI: 10.1152/ajpcell.00244.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We recently demonstrated increased superoxide (O2(·-)) and decreased H2O2 levels in pulmonary arteries of chronic hypoxia-exposed wild-type and normoxic superoxide dismutase 1 (SOD1) knockout mice. We also showed that this reciprocal change in O2(·-) and H2O2 is associated with elevated activity of nuclear factor of activated T cells isoform c3 (NFATc3) in pulmonary arterial smooth muscle cells (PASMC). This suggests that an imbalance in reactive oxygen species levels is required for NFATc3 activation. However, how such imbalance activates NFATc3 is unknown. This study evaluated the importance of O2(·-) and H2O2 in the regulation of NFATc3 activity. We tested the hypothesis that an increase in O2(·-) enhances actin cytoskeleton dynamics and a decrease in H2O2 enhances intracellular Ca(2+) concentration, contributing to NFATc3 nuclear import and activation in PASMC. We demonstrate that, in PASMC, endothelin-1 increases O2(·-) while decreasing H2O2 production through the decrease in SOD1 activity without affecting SOD protein levels. We further demonstrate that O2(·-) promotes, while H2O2 inhibits, NFATc3 activation in PASMC. Additionally, increased O2(·-)-to-H2O2 ratio activates NFATc3, even in the absence of a Gq protein-coupled receptor agonist. Furthermore, O2(·-)-dependent actin polymerization and low intracellular H2O2 concentration-dependent increases in intracellular Ca(2+) concentration contribute to NFATc3 activation. Together, these studies define important and novel regulatory mechanisms of NFATc3 activation in PASMC by reactive oxygen species.
Collapse
Affiliation(s)
- Juan Manuel Ramiro-Diaz
- Vascular Physiology Group, Department of Cell Biology and Physiology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Wieslawa Giermakowska
- Vascular Physiology Group, Department of Cell Biology and Physiology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - John M Weaver
- Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico; and Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Laura V Gonzalez Bosc
- Vascular Physiology Group, Department of Cell Biology and Physiology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico;
| |
Collapse
|
47
|
Olschewski A, Papp R, Nagaraj C, Olschewski H. Ion channels and transporters as therapeutic targets in the pulmonary circulation. Pharmacol Ther 2014; 144:349-68. [PMID: 25108211 DOI: 10.1016/j.pharmthera.2014.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 10/24/2022]
Abstract
Pulmonary circulation is a low pressure, low resistance, high flow system. The low resting vascular tone is maintained by the concerted action of ion channels, exchangers and pumps. Under physiological as well as pathophysiological conditions, they are targets of locally secreted or circulating vasodilators and/or vasoconstrictors, leading to changes in expression or to posttranslational modifications. Both structural changes in the pulmonary arteries and a sustained increase in pulmonary vascular tone result in pulmonary vascular remodeling contributing to morbidity and mortality in pediatric and adult patients. There is increasing evidence demonstrating the pivotal role of ion channels such as K(+) and Cl(-) or transient receptor potential channels in different cell types which are thought to play a key role in vasoconstrictive remodeling. This review focuses on ion channels, exchangers and pumps in the pulmonary circulation and summarizes their putative pathophysiological as well as therapeutic role in pulmonary vascular remodeling. A better understanding of the mechanisms of their actions may allow for the development of new options for attenuating acute and chronic pulmonary vasoconstriction and remodeling treating the devastating disease pulmonary hypertension.
Collapse
Affiliation(s)
- Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Experimental Anesthesiology, Department of Anesthesia and Intensive Care Medicine, Medical University of Graz, Austria.
| | - Rita Papp
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Horst Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Austria
| |
Collapse
|
48
|
Vadivel A, Alphonse RS, Ionescu L, Machado DS, O’Reilly M, Eaton F, Haromy A, Michelakis ED, Thébaud B. Exogenous hydrogen sulfide (H2S) protects alveolar growth in experimental O2-induced neonatal lung injury. PLoS One 2014; 9:e90965. [PMID: 24603989 PMCID: PMC3946270 DOI: 10.1371/journal.pone.0090965] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 02/05/2014] [Indexed: 01/02/2023] Open
Abstract
Background Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, remains a major health problem. BPD is characterized by impaired alveolar development and complicated by pulmonary hypertension (PHT). Currently there is no specific treatment for BPD. Hydrogen sulfide (H2S), carbon monoxide and nitric oxide (NO), belong to a class of endogenously synthesized gaseous molecules referred to as gasotransmitters. While inhaled NO is already used for the treatment of neonatal PHT and currently tested for the prevention of BPD, H2S has until recently been regarded exclusively as a toxic gas. Recent evidence suggests that endogenous H2S exerts beneficial biological effects, including cytoprotection and vasodilatation. We hypothesized that H2S preserves normal alveolar development and prevents PHT in experimental BPD. Methods We took advantage of a recently described slow-releasing H2S donor, GYY4137 (morpholin-4-ium-4-methoxyphenyl(morpholino) phosphinodithioate) to study its lung protective potential in vitro and in vivo. Results In vitro, GYY4137 promoted capillary-like network formation, viability and reduced reactive oxygen species in hyperoxia-exposed human pulmonary artery endothelial cells. GYY4137 also protected mitochondrial function in alveolar epithelial cells. In vivo, GYY4137 preserved and restored normal alveolar growth in rat pups exposed from birth for 2 weeks to hyperoxia. GYY4137 also attenuated PHT as determined by improved pulmonary arterial acceleration time on echo-Doppler, pulmonary artery remodeling and right ventricular hypertrophy. GYY4137 also prevented pulmonary artery smooth muscle cell proliferation. Conclusions H2S protects from impaired alveolar growth and PHT in experimental O2-induced lung injury. H2S warrants further investigation as a new therapeutic target for alveolar damage and PHT.
Collapse
Affiliation(s)
- Arul Vadivel
- Ottawa Hospital Research Institute, Sprott Center for Stem Cell Research, Regenerative Medicine Program and Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - Rajesh S. Alphonse
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Lavinia Ionescu
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Desiree S. Machado
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Megan O’Reilly
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Farah Eaton
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Al Haromy
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Evangelos D. Michelakis
- Department of Pediatrics, School of Human Development, Women and Children’s Health Research Institute, Cardiovascular Research Center and Pulmonary Research Group, University of Alberta, Edmonton, Canada
| | - Bernard Thébaud
- Ottawa Hospital Research Institute, Sprott Center for Stem Cell Research, Regenerative Medicine Program and Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
| |
Collapse
|
49
|
Yan J, Chen R, Liu P, Gu Y. Docosahexaenoic acid attenuates hypoxic pulmonary vasoconstriction by activating the large conductance Ca2+-activated K+ currents in pulmonary artery smooth muscle cells. Pulm Pharmacol Ther 2013; 28:9-16. [PMID: 24269522 DOI: 10.1016/j.pupt.2013.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 10/14/2013] [Accepted: 11/11/2013] [Indexed: 01/31/2023]
Abstract
BACKGROUND The inhibition of potassium (K(+)) channels plays an important role in pulmonary circulation for its close relationship with hypoxic pulmonary vasoconstriction (HPV). Docosahexaenoic acid (DHA), a n-3 polyunsaturated fatty acid, is well known for its prevention and treatment of cardiovascular diseases. However the role which DHA plays in HPV remains unclear. Here, we tested the hypothesis that DHA contributes to pulmonary vascular tone by activating the large conductance Ca(2+)-activated K(+) (BKCa) channels via calcium sparks. METHODS AND RESULTS Isolated resistance pulmonary artery preparation was used to study the vasomotor response to DHA. Pulmonary artery smooth muscle cells (PASMCs) were isolated from third- to fourth order branches of pulmonary arteries by collagenase digestion method. BKCa and the voltage-dependent potassium channel (Kv) currents in PASMCs were measured by the whole-cell patch-clamp technique. Fluo-8 was used as a fluorescence indicator for the real-time measurement of calcium dynamics in PASMCs. DHA dilated resistance pulmonary arteries in a dose-dependent manner in hypoxic or normoxic solution, and the effects of DHA were abolished after pre-treatment with heparin (100 μg/ml), a 1,4,5-triphosphate (IP3) receptor (IP3R) inhibitor or iberiotoxin (100 nmol/L), a specific inhibitor of BKCa channel. DHA activated BKCa channels in a dose-dependent manner, however, the activation induced by DHA was not seen in PASMCs pre-incubated with heparin. While the Kv currents decreased from 102.6 ± 5.4 to 36.5 ± 6.7 pA/pF by addition of 10 μmol/L DHA. DHA also caused calcium sparks in PASMCs. Moreover, hypoxia inhibited BKCa currents in PASMCs, but this inhibition was reversed by DHA. CONCLUSION Our findings suggest that DHA is a novel BKCa opener in PASMCs, which may indicate a potential therapeutic role in HPV.
Collapse
Affiliation(s)
- Jinchuan Yan
- Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu Province 212001, China.
| | - Rui Chen
- Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu Province 212001, China
| | - Peijing Liu
- Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu Province 212001, China.
| | - Yuchun Gu
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| |
Collapse
|
50
|
Reho JJ, Zheng X, Fisher SA. Smooth muscle contractile diversity in the control of regional circulations. Am J Physiol Heart Circ Physiol 2013; 306:H163-72. [PMID: 24186099 DOI: 10.1152/ajpheart.00493.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Each regional circulation has unique requirements for blood flow and thus unique mechanisms by which it is regulated. In this review we consider the role of smooth muscle contractile diversity in determining the unique properties of selected regional circulations and its potential influence on drug targeting in disease. Functionally smooth muscle diversity can be dichotomized into fast versus slow contractile gene programs, giving rise to phasic versus tonic smooth muscle phenotypes, respectively. Large conduit vessel smooth muscle is of the tonic phenotype; in contrast, there is great smooth muscle contractile diversity in the other parts of the vascular system. In the renal circulation, afferent and efferent arterioles are arranged in series and determine glomerular filtration rate. The afferent arteriole has features of phasic smooth muscle, whereas the efferent arteriole has features of tonic smooth muscle. In the splanchnic circulation, the portal vein and hepatic artery are arranged in parallel and supply blood for detoxification and metabolism to the liver. Unique features of this circulation include the hepatic-arterial buffer response to regulate blood flow and the phasic contractile properties of the portal vein. Unique features of the pulmonary circulation include the low vascular resistance and hypoxic pulmonary vasoconstriction, the latter attribute inherent to the smooth muscle cells but the mechanism uncertain. We consider how these unique properties may allow for selective drug targeting of regional circulations for therapeutic benefit and point out gaps in our knowledge and areas in need of further investigation.
Collapse
Affiliation(s)
- John J Reho
- Division of Cardiology, School of Medicine, University of Maryland, Baltimore, Maryland
| | | | | |
Collapse
|