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Csáki R, Nagaraj C, Almássy J, Khozeimeh MA, Jeremic D, Olschewski H, Dobolyi A, Hoetzenecker K, Olschewski A, Enyedi P, Lengyel M. The TREK-1 potassium channel is a potential pharmacological target for vasorelaxation in pulmonary hypertension. Br J Pharmacol 2024; 181:3576-3593. [PMID: 38807478 DOI: 10.1111/bph.16426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 03/22/2024] [Accepted: 04/09/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND AND PURPOSE Pulmonary arterial hypertension (PAH) is a progressive disease in which chronic membrane potential (Em) depolarisation of the pulmonary arterial smooth muscle cells (PASMCs) causes calcium overload, a key pathological alteration. Under resting conditions, the negative Em is mainly set by two pore domain potassium (K2P) channels, of which the TASK-1 has been extensively investigated. EXPERIMENTAL APPROACH Ion channel currents and membrane potential of primary cultured human(h) PASMCs were measured using the voltage- and current clamp methods. Intracellular [Ca2+] was monitored using fluorescent microscopy. Pulmonary BP and vascular tone measurements were also performed ex vivo using a rat PAH model. KEY RESULTS TREK-1 was the most abundantly expressed K2P in hPASMCs of healthy donors and idiopathic(I) PAH patients. Background K+-current was similar in hPASMCs for both groups and significantly enhanced by the TREK activator ML-335. In donor hPASMCs, siRNA silencing or pharmacological inhibition of TREK-1 caused depolarisation, reminiscent of the electrophysiological phenotype of idiopathic PAH. ML-335 hyperpolarised donor hPASMCs and normalised the Em of IPAH hPASMCs. A close link was found between TREK-1 activity and intracellular Ca2+-signalling using a channel activator, ML-335, and an inhibitor, spadin. In the rat, ML-335 relaxed isolated pre-constricted pulmonary arteries and significantly decreased pulmonary arterial pressure in the isolated perfused lung. CONCLUSIONS AND IMPLICATIONS These data suggest that TREK-1is a key factor in Em setting and Ca2+ homeostasis of hPASMC, and therefore, essential for maintenance of a low resting pulmonary vascular tone. Thus TREK-1 may represent a new therapeutic target for PAH.
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MESH Headings
- Potassium Channels, Tandem Pore Domain/antagonists & inhibitors
- Potassium Channels, Tandem Pore Domain/metabolism
- Animals
- Humans
- Hypertension, Pulmonary/drug therapy
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/physiopathology
- Male
- Rats
- Vasodilation/drug effects
- Pulmonary Artery/drug effects
- Pulmonary Artery/metabolism
- Cells, Cultured
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Female
- Rats, Sprague-Dawley
- Membrane Potentials/drug effects
- Rats, Wistar
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Calcium/metabolism
- Middle Aged
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Affiliation(s)
- Réka Csáki
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Chandran Nagaraj
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - János Almássy
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | | | - Dusan Jeremic
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria
| | - Horst Olschewski
- Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Graz, Austria
| | - Alice Dobolyi
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Konrad Hoetzenecker
- Department of Thoracic Surgery, Medical University of Vienna, Vienna, Austria
| | - Andrea Olschewski
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria
| | - Péter Enyedi
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Miklós Lengyel
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
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Balistrieri A, Makino A, Yuan JXJ. Pathophysiology and pathogenic mechanisms of pulmonary hypertension: role of membrane receptors, ion channels, and Ca 2+ signaling. Physiol Rev 2023; 103:1827-1897. [PMID: 36422993 PMCID: PMC10110735 DOI: 10.1152/physrev.00030.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/11/2022] [Accepted: 11/19/2022] [Indexed: 11/25/2022] Open
Abstract
The pulmonary circulation is a low-resistance, low-pressure, and high-compliance system that allows the lungs to receive the entire cardiac output. Pulmonary arterial pressure is a function of cardiac output and pulmonary vascular resistance, and pulmonary vascular resistance is inversely proportional to the fourth power of the intraluminal radius of the pulmonary artery. Therefore, a very small decrease of the pulmonary vascular lumen diameter results in a significant increase in pulmonary vascular resistance and pulmonary arterial pressure. Pulmonary arterial hypertension is a fatal and progressive disease with poor prognosis. Regardless of the initial pathogenic triggers, sustained pulmonary vasoconstriction, concentric vascular remodeling, occlusive intimal lesions, in situ thrombosis, and vascular wall stiffening are the major and direct causes for elevated pulmonary vascular resistance in patients with pulmonary arterial hypertension and other forms of precapillary pulmonary hypertension. In this review, we aim to discuss the basic principles and physiological mechanisms involved in the regulation of lung vascular hemodynamics and pulmonary vascular function, the changes in the pulmonary vasculature that contribute to the increased vascular resistance and arterial pressure, and the pathogenic mechanisms involved in the development and progression of pulmonary hypertension. We focus on reviewing the pathogenic roles of membrane receptors, ion channels, and intracellular Ca2+ signaling in pulmonary vascular smooth muscle cells in the development and progression of pulmonary hypertension.
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Affiliation(s)
- Angela Balistrieri
- Section of Physiology, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
- Harvard University, Cambridge, Massachusetts
| | - Ayako Makino
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Jason X-J Yuan
- Section of Physiology, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
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Yeo Y, Jeong H, Kim M, Choi Y, Kim KL, Suh W. Crosstalk between BMP signaling and KCNK3 in phenotypic switching of pulmonary vascular smooth muscle cells. BMB Rep 2022; 55:565-570. [PMID: 36016502 PMCID: PMC9712703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/11/2022] [Accepted: 08/12/2022] [Indexed: 12/14/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a progressive and devastating disease whose pathogenesis is associated with a phenotypic switch of pulmonary arterial vascular smooth muscle cells (PASMCs). Bone morphogenetic protein (BMP) signaling and potassium two pore domain channel subfamily K member 3 (KCNK3) play crucial roles in PAH pathogenesis. However, the relationship between BMP signaling and KCNK3 expression in the PASMC phenotypic switching process has not been studied. In this study, we explored the effect of BMPs on KCNK3 expression and the role of KCNK3 in the BMP-mediated PASMC phenotypic switch. Expression levels of BMP receptor 2 (BMPR2) and KCNK3 were downregulated in PASMCs of rats with PAH compared to those in normal controls, implying a possible association between BMP/BMPR2 signaling and KCNK3 expression in the pulmonary vasculature. Treatment with BMP2, BMP4, and BMP7 significantly increased KCNK3 expression in primary human PASMCs (HPASMCs). BMPR2 knockdown and treatment with Smad1/5 signaling inhibitor substantially abrogated the BMP-induced increase in KCNK3 expression, suggesting that KCNK3 expression in HPASMCs is regulated by the canonical BMP-BMPR2-Smad1/5 signaling pathway. Furthermore, KCNK3 knockdown and treatment with a KCNK3 channel blocker completely blocked BMP-mediated anti-proliferation and expression of contractile marker genes in HPAMSCs, suggesting that the expression and functional activity of KCNK3 are required for BMP-mediated acquisition of the quiescent PASMC phenotype. Overall, our findings show a crosstalk between BMP signaling and KCNK3 in regulating the PASMC phenotype, wherein BMPs upregulate KCNK3 expression and KCNK3 then mediates BMP-induced phenotypic switching of PASMCs. Our results indicate that the dysfunction and/or downregulation of BMPR2 and KCNK3 observed in PAH work together to induce aberrant changes in the PASMC phenotype, providing insights into the complex molecular pathogenesis of PAH. [BMB Reports 2022; 55(11): 565-570].
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Affiliation(s)
- Yeongju Yeo
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Hayoung Jeong
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Minju Kim
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Yanghee Choi
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Koung Li Kim
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Wonhee Suh
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
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Yeo Y, Jeong H, Kim M, Choi Y, Kim KL, Suh W. Crosstalk between BMP signaling and KCNK3 in phenotypic switching of pulmonary vascular smooth muscle cells. BMB Rep 2022; 55:565-570. [PMID: 36016502 PMCID: PMC9712703 DOI: 10.5483/bmbrep.2022.55.11.098] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/11/2022] [Accepted: 08/12/2022] [Indexed: 02/18/2024] Open
Abstract
Pulmonary arterial hypertension (PAH) is a progressive and devastating disease whose pathogenesis is associated with a phenotypic switch of pulmonary arterial vascular smooth muscle cells (PASMCs). Bone morphogenetic protein (BMP) signaling and potassium two pore domain channel subfamily K member 3 (KCNK3) play crucial roles in PAH pathogenesis. However, the relationship between BMP signaling and KCNK3 expression in the PASMC phenotypic switching process has not been studied. In this study, we explored the effect of BMPs on KCNK3 expression and the role of KCNK3 in the BMP-mediated PASMC phenotypic switch. Expression levels of BMP receptor 2 (BMPR2) and KCNK3 were downregulated in PASMCs of rats with PAH compared to those in normal controls, implying a possible association between BMP/BMPR2 signaling and KCNK3 expression in the pulmonary vasculature. Treatment with BMP2, BMP4, and BMP7 significantly increased KCNK3 expression in primary human PASMCs (HPASMCs). BMPR2 knockdown and treatment with Smad1/5 signaling inhibitor substantially abrogated the BMP-induced increase in KCNK3 expression, suggesting that KCNK3 expression in HPASMCs is regulated by the canonical BMP-BMPR2-Smad1/5 signaling pathway. Furthermore, KCNK3 knockdown and treatment with a KCNK3 channel blocker completely blocked BMP-mediated anti-proliferation and expression of contractile marker genes in HPAMSCs, suggesting that the expression and functional activity of KCNK3 are required for BMP-mediated acquisition of the quiescent PASMC phenotype. Overall, our findings show a crosstalk between BMP signaling and KCNK3 in regulating the PASMC phenotype, wherein BMPs upregulate KCNK3 expression and KCNK3 then mediates BMP-induced phenotypic switching of PASMCs. Our results indicate that the dysfunction and/or downregulation of BMPR2 and KCNK3 observed in PAH work together to induce aberrant changes in the PASMC phenotype, providing insights into the complex molecular pathogenesis of PAH. [BMB Reports 2022; 55(11): 565-570].
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Affiliation(s)
- Yeongju Yeo
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Hayoung Jeong
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Minju Kim
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Yanghee Choi
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Koung Li Kim
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Wonhee Suh
- Department of Global Innovative Drug, The Graduate School of Chung-Ang University, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
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Khreesha L, Qaswal AB, Al Omari B, Albliwi MA, Ababneh O, Albanna A, Abunab'ah A, Iswaid M, Alarood S, Guzu H, Alshawabkeh G, Zayed FM, Abuhilaleh MA, Al-Jbour MN, Obeidat S, Suleiman A. Quantum Tunneling-Induced Membrane Depolarization Can Explain the Cellular Effects Mediated by Lithium: Mathematical Modeling and Hypothesis. MEMBRANES 2021; 11:851. [PMID: 34832080 PMCID: PMC8625630 DOI: 10.3390/membranes11110851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022]
Abstract
Lithium imposes several cellular effects allegedly through multiple physiological mechanisms. Membrane depolarization is a potential unifying concept of these mechanisms. Multiple inherent imperfections of classical electrophysiology limit its ability to fully explain the depolarizing effect of lithium ions; these include incapacity to explain the high resting permeability of lithium ions, the degree of depolarization with extracellular lithium concentration, depolarization at low therapeutic concentration, or the differences between the two lithium isotopes Li-6 and Li-7 in terms of depolarization. In this study, we implemented a mathematical model that explains the quantum tunneling of lithium ions through the closed gates of voltage-gated sodium channels as a conclusive approach that decodes the depolarizing action of lithium. Additionally, we compared our model to the classical model available and reported the differences. Our results showed that lithium can achieve high quantum membrane conductance at the resting state, which leads to significant depolarization. The quantum model infers that quantum membrane conductance of lithium ions emerges from quantum tunneling of lithium through the closed gates of sodium channels. It also differentiates between the two lithium isotopes (Li-6 and Li-7) in terms of depolarization compared with the previous classical model. Moreover, our study listed many examples of the cellular effects of lithium and membrane depolarization to show similarity and consistency with model predictions. In conclusion, the study suggests that lithium mediates its multiple cellular effects through membrane depolarization, and this can be comprehensively explained by the quantum tunneling model of lithium ions.
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Affiliation(s)
- Lubna Khreesha
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | | | - Baheth Al Omari
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | | | - Omar Ababneh
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | - Ahmad Albanna
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | | | - Mohammad Iswaid
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | - Salameh Alarood
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | - Hasan Guzu
- Anesthesia Department, Farah Medical Campus, 18 Mai Zeyadeh Street, Amman 11942, Jordan
| | - Ghadeer Alshawabkeh
- Anesthesia and Pain Management Department, King Hussein Cancer Center, Amman 11942, Jordan
| | | | | | | | - Salameh Obeidat
- Department of Anesthesia, Intensive Care and Pain Management, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Aiman Suleiman
- Department of Anesthesia, Intensive Care and Pain Management, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
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Jernigan NL, Naik JS, Resta TC. Acid-sensing ion channel 1 contributes to pulmonary arterial smooth muscle cell depolarization following hypoxic pulmonary hypertension. J Physiol 2021; 599:4749-4762. [PMID: 34487355 DOI: 10.1113/jp282231] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 08/31/2021] [Indexed: 12/17/2022] Open
Abstract
Pulmonary hypertension is characterized by sustained vasoconstriction and remodelling of the small pulmonary arteries, which is associated with persistent depolarization of the resting membrane potential (Em ) of pulmonary arterial smooth muscle cells (PASMCs). It is well-known that the underlying mechanism of this depolarization includes inhibition of K+ channels; however, whether other ion channels contribute to this depolarization is unknown. We previously reported that acid-sensing ion channel 1 (ASIC1), a non-selective cation channel (NSCC) that conducts both Na+ and Ca2+ , is present in PASMCs and contributes to the development of chronic hypoxia (CH)-induced pulmonary hypertension. Therefore, we tested the hypothesis that ASIC1-mediated Na+ influx contributes to PASMC Em regulation following CH-induced pulmonary hypertension. Using sharp electrode intracellular recordings in isolated, pressurized small pulmonary arteries from rats and mice, we show that exposure to CH leads to PASMC membrane depolarization compared with control animals, and this is independent of intraluminal pressure-induced depolarization. In addition to a decrease in PASMC whole-cell K+ currents following CH, we demonstrate that whole-cell NSCC currents are increased and essential to the persistent CH-induced Em depolarization in PASMCs. Both the specific inhibitor of ASIC1, psalmotoxin 1, and global knockout of ASIC1 (Asic1-/- ) prevents CH-induced Em depolarization and largely inhibits whole-cell NSCC currents, without affecting whole-cell K+ currents. Our results show a combination of factors, including inhibition of K+ efflux and augmented Na+ influx, mediate CH-induced PASMC depolarization. Furthermore, this study demonstrates a novel role for ASIC1 in the regulation of Em in PASMCs during CH-induced pulmonary hypertension. KEY POINTS: In pulmonary hypertensive patients and animal models of pulmonary hypertension, the resting membrane potential (Em ) of pulmonary arterial smooth muscle cells (PASMCs) is persistently depolarized. In addition to the well-established reduction of K+ conductance, we show that non-selective cation channel currents are increased and essential to the persistent Em depolarization in PASMCs following chronic hypoxia (CH)-induced pulmonary hypertension. The current study provides novel evidence that acid-sensing ion channel 1 (ASIC1)-mediated Na+ influx induces membrane depolarization and regulates Em in PASMCs following CH exposure. Although fairly quiescent under control conditions, our findings demonstrate a pathological function of ASIC1 in the development of chronic hypoxia-induced pulmonary hypertension.
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Affiliation(s)
- Nikki L Jernigan
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - Jay S Naik
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - Thomas C Resta
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
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Fazal S, Bisserier M, Hadri L. Molecular and Genetic Profiling for Precision Medicines in Pulmonary Arterial Hypertension. Cells 2021; 10:cells10030638. [PMID: 33805595 PMCID: PMC7999465 DOI: 10.3390/cells10030638] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 12/11/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a rare and chronic lung disease characterized by progressive occlusion of the small pulmonary arteries, which is associated with structural and functional alteration of the smooth muscle cells and endothelial cells within the pulmonary vasculature. Excessive vascular remodeling is, in part, responsible for high pulmonary vascular resistance and the mean pulmonary arterial pressure, increasing the transpulmonary gradient and the right ventricular “pressure overload”, which may result in right ventricular (RV) dysfunction and failure. Current technological advances in multi-omics approaches, high-throughput sequencing, and computational methods have provided valuable tools in molecular profiling and led to the identification of numerous genetic variants in PAH patients. In this review, we summarized the pathogenesis, classification, and current treatments of the PAH disease. Additionally, we outlined the latest next-generation sequencing technologies and the consequences of common genetic variants underlying PAH susceptibility and disease progression. Finally, we discuss the importance of molecular genetic testing for precision medicine in PAH and the future of genomic medicines, including gene-editing technologies and gene therapies, as emerging alternative approaches to overcome genetic disorders in PAH.
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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.
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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
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Prins KW, Thenappan T, Weir EK, Kalra R, Pritzker M, Archer SL. Repurposing Medications for Treatment of Pulmonary Arterial Hypertension: What's Old Is New Again. J Am Heart Assoc 2020; 8:e011343. [PMID: 30590974 PMCID: PMC6405714 DOI: 10.1161/jaha.118.011343] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Kurt W Prins
- 1 Cardiovascular Division University of Minnesota Medical School Minneapolis MN
| | - Thenappan Thenappan
- 1 Cardiovascular Division University of Minnesota Medical School Minneapolis MN
| | - E Kenneth Weir
- 1 Cardiovascular Division University of Minnesota Medical School Minneapolis MN
| | - Rajat Kalra
- 1 Cardiovascular Division University of Minnesota Medical School Minneapolis MN
| | - Marc Pritzker
- 1 Cardiovascular Division University of Minnesota Medical School Minneapolis MN
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Babicheva A, Ayon RJ, Zhao T, Ek Vitorin JF, Pohl NM, Yamamura A, Yamamura H, Quinton BA, Ba M, Wu L, Ravellette KS, Rahimi S, Balistrieri F, Harrington A, Vanderpool RR, Thistlethwaite PA, Makino A, Yuan JXJ. MicroRNA-mediated downregulation of K + channels in pulmonary arterial hypertension. Am J Physiol Lung Cell Mol Physiol 2020; 318:L10-L26. [PMID: 31553627 PMCID: PMC6985878 DOI: 10.1152/ajplung.00010.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 08/19/2019] [Accepted: 09/06/2019] [Indexed: 12/22/2022] Open
Abstract
Downregulated expression of K+ channels and decreased K+ currents in pulmonary artery smooth muscle cells (PASMC) have been implicated in the development of sustained pulmonary vasoconstriction and vascular remodeling in patients with idiopathic pulmonary arterial hypertension (IPAH). However, it is unclear exactly how K+ channels are downregulated in IPAH-PASMC. MicroRNAs (miRNAs) are small non-coding RNAs that are capable of posttranscriptionally regulating gene expression by binding to the 3'-untranslated regions of their targeted mRNAs. Here, we report that specific miRNAs are responsible for the decreased K+ channel expression and function in IPAH-PASMC. We identified 3 miRNAs (miR-29b, miR-138, and miR-222) that were highly expressed in IPAH-PASMC in comparison to normal PASMC (>2.5-fold difference). Selectively upregulated miRNAs are correlated with the decreased expression and attenuated activity of K+ channels. Overexpression of miR-29b, miR-138, or miR-222 in normal PASMC significantly decreased whole cell K+ currents and downregulated voltage-gated K+ channel 1.5 (KV1.5/KCNA5) in normal PASMC. Inhibition of miR-29b in IPAH-PASMC completely recovered K+ channel function and KV1.5 expression, while miR-138 and miR-222 had a partial or no effect. Luciferase assays further revealed that KV1.5 is a direct target of miR-29b. Additionally, overexpression of miR-29b in normal PASMC decreased large-conductance Ca2+-activated K+ (BKCa) channel currents and downregulated BKCa channel β1 subunit (BKCaβ1 or KCNMB1) expression, while inhibition of miR-29b in IPAH-PASMC increased BKCa channel activity and BKCaβ1 levels. These data indicate upregulated miR-29b contributes at least partially to the attenuated function and expression of KV and BKCa channels in PASMC from patients with IPAH.
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Affiliation(s)
- Aleksandra Babicheva
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Ramon J Ayon
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Tengteng Zhao
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Jose F Ek Vitorin
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Nicole M Pohl
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Aya Yamamura
- Kinjo Gakuin University School of Pharmacy, Nagoya, Japan
| | - Hisao Yamamura
- Nagoya City University Graduate School of Pharmaceutical Sciences, Nagoya, Japan
| | - Brooke A Quinton
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Manqing Ba
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Linda Wu
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Keeley S Ravellette
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Shamin Rahimi
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
| | - Francesca Balistrieri
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
| | - Angela Harrington
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
| | - Rebecca R Vanderpool
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | | | - Ayako Makino
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, California
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
| | - Jason X-J Yuan
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
- Departments of Medicine and Physiology, The University of Arizona, Tucson, Arizona
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
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Dong F, Zhang J, Zhu S, Lan T, Yang J, Li L. Chrysin Alleviates Chronic Hypoxia–Induced Pulmonary Hypertension by Reducing Intracellular Calcium Concentration in Pulmonary Arterial Smooth Muscle Cells. J Cardiovasc Pharmacol 2019; 74:426-435. [DOI: 10.1097/fjc.0000000000000726] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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12
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Affiliation(s)
- Aleksandra Babicheva
- From the Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, School of Medicine, San Diego, CA
| | - Tengteng Zhao
- From the Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, School of Medicine, San Diego, CA
| | - Jason X-J Yuan
- From the Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, School of Medicine, San Diego, CA
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13
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Morikawa S, Iribar H, Gutiérrez-Rivera A, Ezaki T, Izeta A. Pericytes in Cutaneous Wound Healing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1147:1-63. [DOI: 10.1007/978-3-030-16908-4_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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14
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Lambert M, Capuano V, Olschewski A, Sabourin J, Nagaraj C, Girerd B, Weatherald J, Humbert M, Antigny F. Ion Channels in Pulmonary Hypertension: A Therapeutic Interest? Int J Mol Sci 2018; 19:ijms19103162. [PMID: 30322215 PMCID: PMC6214085 DOI: 10.3390/ijms19103162] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/05/2018] [Accepted: 10/08/2018] [Indexed: 12/25/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a multifactorial and severe disease without curative therapies. PAH pathobiology involves altered pulmonary arterial tone, endothelial dysfunction, distal pulmonary vessel remodeling, and inflammation, which could all depend on ion channel activities (K⁺, Ca2+, Na⁺ and Cl-). This review focuses on ion channels in the pulmonary vasculature and discusses their pathophysiological contribution to PAH as well as their therapeutic potential in PAH.
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Affiliation(s)
- Mélanie Lambert
- Univ. Paris-Sud, Faculté de Médecine, 94270 Kremlin-Bicêtre, France.
- AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, 94270 Le Kremlin-Bicêtre, France.
- UMRS 999, INSERM and Univ. Paris⁻Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, 92350 Le Plessis Robinson, France.
| | - Véronique Capuano
- Univ. Paris-Sud, Faculté de Médecine, 94270 Kremlin-Bicêtre, France.
- AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, 94270 Le Kremlin-Bicêtre, France.
- UMRS 999, INSERM and Univ. Paris⁻Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, 92350 Le Plessis Robinson, France.
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Stiftingtalstrasse 24, Graz 8010, Austria.
- Department of Physiology, Medical University Graz, Neue Stiftingtalstraße 6, Graz 8010, Austria.
| | - Jessica Sabourin
- Signalisation et Physiopathologie Cardiovasculaire, UMRS 1180, Univ. Paris-Sud, INSERM, Université Paris-Saclay, 92296 Châtenay-Malabry, France.
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Stiftingtalstrasse 24, Graz 8010, Austria.
| | - Barbara Girerd
- Univ. Paris-Sud, Faculté de Médecine, 94270 Kremlin-Bicêtre, France.
- AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, 94270 Le Kremlin-Bicêtre, France.
- UMRS 999, INSERM and Univ. Paris⁻Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, 92350 Le Plessis Robinson, France.
| | - Jason Weatherald
- Univ. Paris-Sud, Faculté de Médecine, 94270 Kremlin-Bicêtre, France.
- AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, 94270 Le Kremlin-Bicêtre, France.
- UMRS 999, INSERM and Univ. Paris⁻Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, 92350 Le Plessis Robinson, France.
- Division of Respirology, Department of Medicine, University of Calgary, Calgary, AB T1Y 6J4, Canada.
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB T1Y 6J4, Canada.
| | - Marc Humbert
- Univ. Paris-Sud, Faculté de Médecine, 94270 Kremlin-Bicêtre, France.
- AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, 94270 Le Kremlin-Bicêtre, France.
- UMRS 999, INSERM and Univ. Paris⁻Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, 92350 Le Plessis Robinson, France.
| | - Fabrice Antigny
- Univ. Paris-Sud, Faculté de Médecine, 94270 Kremlin-Bicêtre, France.
- AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, 94270 Le Kremlin-Bicêtre, France.
- UMRS 999, INSERM and Univ. Paris⁻Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, 92350 Le Plessis Robinson, France.
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15
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Rorsman NJG, Ta CM, Garnett H, Swietach P, Tammaro P. Defining the ionic mechanisms of optogenetic control of vascular tone by channelrhodopsin-2. Br J Pharmacol 2018; 175:2028-2045. [PMID: 29486056 PMCID: PMC5979753 DOI: 10.1111/bph.14183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 01/16/2018] [Accepted: 02/14/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Optogenetic control of electromechanical coupling in vascular smooth muscle cells (VSMCs) is emerging as a powerful research tool with potential applications in drug discovery and therapeutics. However, the precise ionic mechanisms involved in this control remain unclear. EXPERIMENTAL APPROACH Cell imaging, patch-clamp electrophysiology and muscle tension recordings were used to define these mechanisms over a wide range of light stimulations. KEY RESULTS Transgenic mice expressing a channelrhodopsin-2 variant [ChR2(H134R)] selectively in VSMCs were generated. Isolated VSMCs obtained from these mice demonstrated blue light-induced depolarizing whole-cell currents. Fine control of artery tone was attained by varying the intensity of the light stimulus. This arterial response was sufficient to overcome the endogenous, melanopsin-mediated, light-evoked, arterial relaxation observed in the presence of contractile agonists. Ca2+ entry through voltage-gated Ca2+ channels, and opening of plasmalemmal depolarizing channels (TMEM16A and TRPM) and intracellular IP3 receptors were involved in the ChR2(H134R)-dependent arterial response to blue light at intensities lower than ~0.1 mW·mm-2 . Light stimuli of greater intensity evoked a significant Ca2+ influx directly through ChR2(H134R) and produced marked intracellular alkalinization of VSMCs. CONCLUSIONS AND IMPLICATIONS We identified the range of light intensity allowing optical control of arterial tone, primarily by means of endogenous channels and without substantial alteration to intracellular pH. Within this range, mice expressing ChR2(H134R) in VSMCs are a powerful experimental model for achieving accurate and tuneable optical voltage-clamp of VSMCs and finely graded control of arterial tone, offering new approaches to the discovery of vasorelaxant drugs.
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Affiliation(s)
- Nils J G Rorsman
- Department of PharmacologyUniversity of OxfordOxfordUK
- OXION Initiative in Ion Channels and DiseaseUniversity of OxfordOxfordUK
| | - Chau M Ta
- Department of PharmacologyUniversity of OxfordOxfordUK
| | | | - Pawel Swietach
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
| | - Paolo Tammaro
- Department of PharmacologyUniversity of OxfordOxfordUK
- OXION Initiative in Ion Channels and DiseaseUniversity of OxfordOxfordUK
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16
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Involvement of AMP-activated Protein Kinase (AMPK) in Regulation of Cell Membrane Potential in a Gastric Cancer Cell Line. Sci Rep 2018; 8:6028. [PMID: 29662080 PMCID: PMC5902619 DOI: 10.1038/s41598-018-24460-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/12/2018] [Indexed: 12/26/2022] Open
Abstract
Membrane potential (Vmem) is a key bioelectric property of non-excitable cells that plays important roles in regulating cell proliferation. However, the regulation of Vmem itself remains largely unexplored. We found that, under nutrient starvation, during which cell division is inhibited, MKN45 gastric cancer cells were in a hyperpolarized state associated with a high intracellular chloride concentration. AMP-activated protein kinase (AMPK) activity increased, and expression of cystic fibrosis transmembrane conductance regulator (CFTR) decreased, in nutrient-starved cells. Furthermore, the increase in intracellular chloride concentration level and Vmem hyperpolarization in nutrient-starved cells was suppressed by inhibition of AMPK activity. Intracellular chloride concentrations and hyperpolarization increased after over-activation of AMPK using the specific activator AICAR or suppression of CFTR activity using specific inhibitor GlyH-101. Under these conditions, proliferation of MKN45 cells was inhibited. These results reveal that AMPK controls the dynamic change in Vmem by regulating CFTR and influencing the intracellular chloride concentration, which in turn influences cell-cycle progression. These findings offer new insights into the mechanisms underlying cell-cycle arrest regulated by AMPK and CFTR.
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17
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Yadav VR, Song T, Mei L, Joseph L, Zheng YM, Wang YX. PLCγ1-PKCε-IP 3R1 signaling plays an important role in hypoxia-induced calcium response in pulmonary artery smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2018; 314:L724-L735. [PMID: 29388468 DOI: 10.1152/ajplung.00243.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxia-induced pulmonary vasoconstriction (HPV) is attributed to an increase in intracellular Ca2+ concentration ([Ca2+]i) in pulmonary artery smooth muscle cells (PASMCs). We have reported that phospholipase C-γ1 (PLCγ1) plays a significant role in the hypoxia-induced increase in [Ca2+]i in PASMCs and attendant HPV. In this study, we intended to determine molecular mechanisms for hypoxic Ca2+ and contractile responses in PASMCs. Our data reveal that hypoxic vasoconstriction occurs in pulmonary arteries, but not in mesenteric arteries. Hypoxia caused a large increase in [Ca2+]i in PASMCs, which is diminished by the PLC inhibitor U73122 and not by its inactive analog U73433 . Hypoxia augments PLCγ1-dependent inositol 1,4,5-trisphosphate (IP3) generation. Exogenous ROS, hydrogen peroxide (H2O2), increases PLCγ1 phosphorylation at tyrosine-783 and IP3 production. IP3 receptor-1 (IP3R1) knock-down remarkably diminishes hypoxia- or H2O2-induced increase in [Ca2+]i. Hypoxia or H2O2 increases the activity of IP3Rs, which is significantly reduced in protein kinase C-ε (PKCε) knockout PASMCs. A higher PLCγ1 expression, activity, and basal [Ca2+]i are found in PASMCs, but not in mesenteric artery smooth muscle cells from mice exposed to chronic hypoxia (CH) for 21 days. CH enhances H2O2- and ATP-induced increase in [Ca2+]i in PASMCs and PLC-dependent, norepinephrine-evoked pulmonary vasoconstriction. In conclusion, acute hypoxia uniquely causes ROS-dependent PLCγ1 activation, IP3 production, PKCε activation, IP3R1 opening, Ca2+ release, and contraction in mouse PASMCs; CH enhances PASM PLCγ1 expression, activity, and function, playing an essential role in pulmonary hypertension in mice.
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Affiliation(s)
- Vishal R Yadav
- Department of Molecular and Cellular Physiology, Albany Medical College , Albany, New York
| | - Tengyao Song
- Department of Molecular and Cellular Physiology, Albany Medical College , Albany, New York
| | - Lin Mei
- Department of Molecular and Cellular Physiology, Albany Medical College , Albany, New York
| | - Leroy Joseph
- Department of Molecular and Cellular Physiology, Albany Medical College , Albany, New York
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College , Albany, New York
| | - Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College , Albany, New York
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18
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Al-Owais MM, Hettiarachchi NT, Boyle JP, Scragg JL, Elies J, Dallas ML, Lippiat JD, Steele DS, Peers C. Multiple mechanisms mediating carbon monoxide inhibition of the voltage-gated K + channel Kv1.5. Cell Death Dis 2017; 8:e3163. [PMID: 29095440 PMCID: PMC5775415 DOI: 10.1038/cddis.2017.568] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 12/13/2022]
Abstract
The voltage-gated K+ channel has key roles in the vasculature and in atrial excitability and contributes to apoptosis in various tissues. In this study, we have explored its regulation by carbon monoxide (CO), a product of the cytoprotective heme oxygenase enzymes, and a recognized toxin. CO inhibited recombinant Kv1.5 expressed in HEK293 cells in a concentration-dependent manner that involved multiple signalling pathways. CO inhibition was partially reversed by superoxide dismutase mimetics and by suppression of mitochondrial reactive oxygen species. CO also elevated intracellular nitric oxide (NO) levels. Prevention of NO formation also partially reversed CO inhibition of Kv1.5, as did inhibition of soluble guanylyl cyclase. CO also elevated intracellular peroxynitrite levels, and a peroxynitrite scavenger markedly attenuated the ability of CO to inhibit Kv1.5. CO caused nitrosylation of Kv1.5, an effect that was also observed in C331A and C346A mutant forms of the channel, which had previously been suggested as nitrosylation sites within Kv1.5. Augmentation of Kv1.5 via exposure to hydrogen peroxide was fully reversed by CO. Native Kv1.5 recorded in HL-1 murine atrial cells was also inhibited by CO. Action potentials recorded in HL-1 cells were increased in amplitude and duration by CO, an effect mimicked and occluded by pharmacological inhibition of Kv1.5. Our data indicate that Kv1.5 is a target for modulation by CO via multiple mechanisms. This regulation has important implications for diverse cellular functions, including excitability, contractility and apoptosis.
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Affiliation(s)
- Moza M Al-Owais
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Nishani T Hettiarachchi
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - John P Boyle
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Jason L Scragg
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Jacobo Elies
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Mark L Dallas
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Jon D Lippiat
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Derek S Steele
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Chris Peers
- Division of Cardiovascular and Diabetes Research, LICAMM, Faculty of Medicine and Health, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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19
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Xu X, Hu H, Wang X, Ye W, Su H, Hu Y, Dong L, Zhang R, Ying K. Involvement of CapG in proliferation and apoptosis of pulmonary arterial smooth muscle cells and in hypoxia-induced pulmonary hypertension rat model. Exp Lung Res 2016; 42:142-53. [PMID: 27093378 DOI: 10.3109/01902148.2016.1160304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE Actin-binding protein capping protein gelsolin-like (CapG) was preferentially expressed in human pulmonary arterial smooth muscle cells (PASMCs) under hypoxia, and reduced CapG expression was accompanied by impaired migration ability in vitro. We intended to investigate the effects of CapG on rat PASMCs and hypoxia-induced pulmonary hypertension (HPH) rat model. MATERIALS AND METHODS We investigated the effect of RNA interference-medicated down-regulation of CapG expression in rat PASMCs as well as in HPH rat model. The proliferation, apoptosis and cell cycle of PASMCs were evaluated. The HPH rat model was established by intratracheal instillation of lentiviral vector and subsequent hypoxia exposure for four weeks. Right ventricular systolic pressure, right ventricular hypertrophy and the percentage of medial wall thickness were measured to evaluate the development of HPH. RESULTS Knock-down CapG in PASMCs resulted in decreased proliferation, increased apoptosis and induced cell cycle inhibition. Down-regulation of CapG expression locally could attenuate pulmonary hypertension, pulmonary vascular remodeling and right ventricular hypertrophy in HPH rat model. CONCLUSIONS Our study indicated that CapG participated in the pathogenesis of pulmonary vascular remodeling in HPH rats, which was probably mediated by promoting the proliferation and inhibiting the apoptosis of PASMCs. We proposed CapG modulating protective effects of pulmonary hypertension.
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Affiliation(s)
- Xiaoling Xu
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Huihui Hu
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Xiaohua Wang
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Wu Ye
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Hua Su
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Yanjie Hu
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Liangliang Dong
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Ruifeng Zhang
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
| | - Kejing Ying
- a Department of Respiratory Medicine , Sir Run Run Shaw Hospital , Zhejiang University School of Medicine , Hangzhou, Zhejiang , China
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20
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Zhang J, Lu W, Chen Y, Jiang Q, Yang K, Li M, Wang Z, Duan X, Xu L, Tang H, Sun D, Wang J. Bortezomib alleviates experimental pulmonary hypertension by regulating intracellular calcium homeostasis in PASMCs. Am J Physiol Cell Physiol 2016; 311:C482-97. [PMID: 27413173 PMCID: PMC5129762 DOI: 10.1152/ajpcell.00324.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 06/27/2016] [Indexed: 01/18/2023]
Abstract
The ubiquitin-proteasome system is considered to be the key regulator of protein degradation. Bortezomib (BTZ) is the first proteasome inhibitor approved by the US Food and Drug Administration for treatment of relapsed multiple myeloma and mantle cell lymphoma. Recently, BTZ treatment was reported to inhibit right ventricular hypertrophy and vascular remodeling in hypoxia-exposed and monocrotaline-injected rats. However, the underlying mechanisms remain poorly understood. We previously confirmed that hypoxia-elevated basal intracellular Ca(2+) concentration ([Ca(2+)]i) and store-operated Ca(2+) entry (SOCE) in pulmonary artery smooth muscle cells (PASMCs) are involved in pulmonary vascular remodeling. In this study we aim to determine whether BTZ attenuates the hypoxia-induced elevation of [Ca(2+)] in PASMCs and the signaling pathway involved in this mechanism. Our results showed that 1) in hypoxia- and monocrotaline-induced rat pulmonary hypertension (PH) models, BTZ markedly attenuated the development and progression of PH, 2) BTZ inhibited the hypoxia-induced increase in cell proliferation, basal [Ca(2+)]i, and SOCE in PASMCs, and 3) BTZ significantly normalized the hypoxia-upregulated expression of hypoxia-inducible factor-1α, bone morphogenetic protein 4, canonical transient receptor potential isoforms 1 and 6, and the hypoxia-downregulated expression of peroxisome proliferator-activated receptor-γ in rat distal pulmonary arteries and PASMCs. These results indicate that BTZ exerts its protective role in the development of PH potentially by inhibiting the canonical transient receptor potential-SOCE-[Ca(2+)]i signaling axis in PASMCs.
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Affiliation(s)
- Jun Zhang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Wenju Lu
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yuqin Chen
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Qian Jiang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Kai Yang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Meichan Li
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Ziyi Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xin Duan
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; and
| | - Lei Xu
- Division of Pulmonary and Critical Care Medicine, Affiliated Hospital of Inner Mongolia Medical University, Huhhot, Inner Mongolia, China
| | - Haiyang Tang
- Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, Arizona
| | - Dejun Sun
- Division of Pulmonary Medicine, The People's Hospital of Inner Mongolia, Hohhot, Inner Mongolia, China
| | - Jian Wang
- State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China; Division of Translational and Regenerative Medicine, Department of Medicine, The University of Arizona, Tucson, Arizona; Division of Pulmonary Medicine, The People's Hospital of Inner Mongolia, Hohhot, Inner Mongolia, China;
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21
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Mishra A, Mohammad G, Norboo T, Newman JH, Pasha MAQ. Lungs at high-altitude: genomic insights into hypoxic responses. J Appl Physiol (1985) 2015; 119:1-15. [DOI: 10.1152/japplphysiol.00513.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 04/20/2015] [Indexed: 11/22/2022] Open
Abstract
Hypobaric hypoxia at high altitude (HA) results in reduced blood arterial oxygen saturation, perfusion of organs with hypoxemic blood, and direct hypoxia of lung tissues. The pulmonary complications in the cells of the pulmonary arterioles due to hypobaric hypoxia are the basis of the pathophysiological mechanisms of high-altitude pulmonary edema (HAPE). Some populations that have dwelled at HA for thousands of years have evolutionarily adapted to this environmental stress; unadapted populations may react with excessive physiological responses that impair health. Individual variations in response to hypoxia and the mechanisms of HA adaptation provide insight into physiological responses. Adaptive and maladaptive responses include alterations in pathways such as oxygen sensing, hypoxia signaling, K+- and Ca2+-gated channels, redox balance, and the renin-angiotensin-aldosterone system. Physiological imbalances are linked with genetic susceptibilities, and nonhomeostatic responses in gene regulation that occur by small RNAs, histone modification, and DNA methylation predispose susceptible humans to these HA illnesses. Elucidation of the interaction of these factors will lead to a more comprehensive understanding of HA adaptations and maladaptations and will lead to new therapeutics for HA disorders related to hypoxic lungs.
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Affiliation(s)
- Aastha Mishra
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Department of Biotechnology, University of Pune, Pune, India
| | - Ghulam Mohammad
- Department of Medicine, SNM Hospital, Leh, Ladakh, J&K, India
| | - Tsering Norboo
- Ladakh Institute of Prevention, Leh, Ladakh, J&K, India; and
| | - John H. Newman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - M. A. Qadar Pasha
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
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22
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Fan Z, Liu B, Zhang S, Liu H, Li Y, Wang D, Liu Y, Li J, Wang N, Liu Y, Zhang B. YM155, a selective survivin inhibitor, reverses chronic hypoxic pulmonary hypertension in rats via upregulating voltage-gated potassium channels. Clin Exp Hypertens 2015; 37:381-7. [PMID: 25856227 DOI: 10.3109/10641963.2014.987390] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To test the hypothesis that chronic hypoxic pulmonary hypertension (CH-PH) is associated with increased survivin and decreased voltage-gated potassium (KV) channels expression in pulmonary arteries, rats were randomized as: normoxia (N); normoxia + YM155, survivin suppressor (NY); hypoxia (H); hypoxia + YM155 (HY). HY group had significantly reduced pulmonary arterial pressure, right ventricular weight and right ventricular hypertrophy compared with H group. Survivin mRNA and protein were detected in pulmonary arteries of rats with CH-PH, but not rats without CH-PH. YM155 downregulated survivin protein and mRNA. KV channel expression and activity were upregulated after YM155 treatment. Survivin may play a role in the pathogenesis of CH-PH.
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Affiliation(s)
- Zaiwen Fan
- Department of Respiratory Medicine, General Hospital of PLA Air Force , Beijing , China
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23
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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]
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Veit F, Pak O, Brandes RP, Weissmann N. Hypoxia-dependent reactive oxygen species signaling in the pulmonary circulation: focus on ion channels. Antioxid Redox Signal 2015; 22:537-52. [PMID: 25545236 PMCID: PMC4322788 DOI: 10.1089/ars.2014.6234] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SIGNIFICANCE An acute lack of oxygen in the lung causes hypoxic pulmonary vasoconstriction, which optimizes gas exchange. In contrast, chronic hypoxia triggers a pathological vascular remodeling causing pulmonary hypertension, and ischemia can cause vascular damage culminating in lung edema. RECENT ADVANCES Regulation of ion channel expression and gating by cellular redox state is a widely accepted mechanism; however, it remains a matter of debate whether an increase or a decrease in reactive oxygen species (ROS) occurs under hypoxic conditions. Ion channel redox regulation has been described in detail for some ion channels, such as Kv channels or TRPC6. However, in general, information on ion channel redox regulation remains scant. CRITICAL ISSUES AND FUTURE DIRECTIONS In addition to the debate of increased versus decreased ROS production during hypoxia, we aim here at describing and deciphering why different oxidants, under different conditions, can cause both activation and inhibition of channel activity. While the upstream pathways affecting channel gating are often well described, we need a better understanding of redox protein modifications to be able to determine the complexity of ion channel redox regulation. Against this background, we summarize the current knowledge on hypoxia-induced ROS-mediated ion channel signaling in the pulmonary circulation.
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Affiliation(s)
- Florian Veit
- 1 Excellence Cluster Cardiopulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), German Center for Lung Research (DZL) , Giessen, Germany
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25
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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]
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26
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Ahmadi A, Ohira H, Mielniczuk LM. FDG PET Imaging for Identifying Pulmonary Hypertension and Right Heart Failure. Curr Cardiol Rep 2014; 17:555. [DOI: 10.1007/s11886-014-0555-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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27
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Tang H, Chen J, Fraidenburg DR, Song S, Sysol JR, Drennan AR, Offermanns S, Ye RD, Bonini MG, Minshall RD, Garcia JGN, Machado RF, Makino A, Yuan JXJ. Deficiency of Akt1, but not Akt2, attenuates the development of pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2014; 308:L208-20. [PMID: 25416384 DOI: 10.1152/ajplung.00242.2014] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Pulmonary vascular remodeling, mainly attributable to enhanced pulmonary arterial smooth muscle cell proliferation and migration, is a major cause for elevated pulmonary vascular resistance and pulmonary arterial pressure in patients with pulmonary hypertension. The signaling cascade through Akt, comprised of three isoforms (Akt1-3) with distinct but overlapping functions, is involved in regulating cell proliferation and migration. This study aims to investigate whether the Akt/mammalian target of rapamycin (mTOR) pathway, and particularly which Akt isoform, contributes to the development and progression of pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension (HPH). Compared with the wild-type littermates, Akt1(-/-) mice were protected against the development and progression of chronic HPH, whereas Akt2(-/-) mice did not demonstrate any significant protection against the development of HPH. Furthermore, pulmonary vascular remodeling was significantly attenuated in the Akt1(-/-) mice, with no significant effect noted in the Akt2(-/-) mice after chronic exposure to normobaric hypoxia (10% O2). Overexpression of the upstream repressor of Akt signaling, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), and conditional and inducible knockout of mTOR in smooth muscle cells were also shown to attenuate the rise in right ventricular systolic pressure and the development of right ventricular hypertrophy. In conclusion, Akt isoforms appear to have a unique function within the pulmonary vasculature, with the Akt1 isoform having a dominant role in pulmonary vascular remodeling associated with HPH. The PTEN/Akt1/mTOR signaling pathway will continue to be a critical area of study in the pathogenesis of pulmonary hypertension, and specific Akt isoforms may help specify therapeutic targets for the treatment of pulmonary hypertension.
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Affiliation(s)
- Haiyang Tang
- Department of Medicine, Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, Arizona; Department of Physiology, The University of Arizona College of Medicine, Tucson, Arizona; Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Jiwang Chen
- Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Dustin R Fraidenburg
- Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Shanshan Song
- Department of Medicine, Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, Arizona; Department of Physiology, The University of Arizona College of Medicine, Tucson, Arizona; Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Justin R Sysol
- Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Abigail R Drennan
- Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Richard D Ye
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Marcelo G Bonini
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Richard D Minshall
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Joe G N Garcia
- Department of Medicine, Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, Arizona
| | - Roberto F Machado
- Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Ayako Makino
- Department of Physiology, The University of Arizona College of Medicine, Tucson, Arizona
| | - Jason X-J Yuan
- Department of Medicine, Division of Translational and Regenerative Medicine, The University of Arizona College of Medicine, Tucson, Arizona; Department of Physiology, The University of Arizona College of Medicine, Tucson, Arizona; Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy Medicine, University of Illinois at Chicago, Chicago, Illinois; Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois; and
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28
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Sedivy V, Joshi S, Ghaly Y, Mizera R, Zaloudikova M, Brennan S, Novotna J, Herget J, Gurney AM. Role of Kv7 channels in responses of the pulmonary circulation to hypoxia. Am J Physiol Lung Cell Mol Physiol 2014; 308:L48-57. [PMID: 25361569 PMCID: PMC4281702 DOI: 10.1152/ajplung.00362.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a beneficial mechanism that diverts blood from hypoxic alveoli to better ventilated areas of the lung, but breathing hypoxic air causes the pulmonary circulation to become hypertensive. Responses to airway hypoxia are associated with depolarization of smooth muscle cells in the pulmonary arteries and reduced activity of K+ channels. As Kv7 channels have been proposed to play a key role in regulating the smooth muscle membrane potential, we investigated their involvement in the development of HPV and hypoxia-induced pulmonary hypertension. Vascular effects of the selective Kv7 blocker, linopirdine, and Kv7 activator, flupirtine, were investigated in isolated, saline-perfused lungs from rats maintained for 3–5 days in an isobaric hypoxic chamber (FiO2 = 0.1) or room air. Linopirdine increased vascular resistance in lungs from normoxic, but not hypoxic rats. This effect was associated with reduced mRNA expression of the Kv7.4 channel α-subunit in hypoxic arteries, whereas Kv7.1 and Kv7.5 were unaffected. Flupirtine had no effect in normoxic lungs but reduced vascular resistance in hypoxic lungs. Moreover, oral dosing with flupirtine (30 mg/kg/day) prevented short-term in vivo hypoxia from increasing pulmonary vascular resistance and sensitizing the arteries to acute hypoxia. These findings suggest a protective role for Kv7.4 channels in the pulmonary circulation, limiting its reactivity to pressor agents and preventing hypoxia-induced pulmonary hypertension. They also provide further support for the therapeutic potential of Kv7 activators in pulmonary vascular disease.
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Affiliation(s)
- Vojtech Sedivy
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic; Department of Paediatrics, Charles University - Second Faculty of Medicine and University Hospital Motol, Prague, Czech Republic; and
| | - Shreena Joshi
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Youssef Ghaly
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Roman Mizera
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Marie Zaloudikova
- Department of Pathophysiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Sean Brennan
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Jana Novotna
- Department of Biochemistry, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Jan Herget
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Alison M Gurney
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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29
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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.
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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
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30
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Potus F, Graydon C, Provencher S, Bonnet S. Vascular remodeling process in pulmonary arterial hypertension, with focus on miR-204 and miR-126 (2013 Grover Conference series). Pulm Circ 2014; 4:175-84. [PMID: 25006436 DOI: 10.1086/675980] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 12/13/2013] [Indexed: 12/19/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized primarily by increased proliferation and resistance to apoptosis in distal pulmonary arteries. Previous literature has demonstrated that the transcription factors NFAT (nuclear factor of activated T cells) and HIF-1α (hypoxia inducible factor 1α) are extensively involved in the pathogenesis of this disease and, more recently, has implicated STAT3 (signal transducer and activator of transcription 3) in their activation. Novel research shows that miR-204, a microRNA recently found to be notably downregulated through induction of PARP-1 (poly [ADP-ribose] polymerase 1) by excessive DNA damage in PAH, inhibits activation of STAT3. Contemporary research also indicates systemic impairment of skeletal muscle microcirculation in PAH and attributes this to a debilitated vascular endothelial growth factor pathway resulting from reduced miR-126 expression in endothelial cells. In this review, we focus on recent research implicating miR-204 and miR-126 in vascular remodeling processes, data that allow a better understanding of PAH molecular pathways and constitute a new hope for future therapy.
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Affiliation(s)
- François Potus
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - Colin Graydon
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - Steeve Provencher
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
| | - Sébastien Bonnet
- Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Québec, Canada
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31
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Papamatheakis DG, Chundu M, Blood AB, Wilson SM. Prenatal programming of pulmonary hypertension induced by chronic hypoxia or ductal ligation in sheep. Pulm Circ 2014; 3:757-80. [PMID: 25006393 DOI: 10.1086/674767] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 07/28/2013] [Indexed: 11/03/2022] Open
Abstract
Pulmonary hypertension of the newborn is caused by a spectrum of functional and structural abnormalities of the cardiopulmonary circuit. The existence of multiple etiologies and an incomplete understanding of the mechanisms of disease progression have hindered the development of effective therapies. Animal models offer a means of gaining a better understanding of the fundamental basis of the disease. To that effect, a number of experimental animal models are being used to generate pulmonary hypertension in the fetus and newborn. In this review, we compare the mechanisms associated with pulmonary hypertension caused by two such models: in utero ligation of the ductus arteriosus and chronic perinatal hypoxia in sheep fetuses and newborns. In this manner, we make direct comparisons between ductal ligation and chronic hypoxia with respect to the associated mechanisms of disease, since multiple studies have been performed with both models in a single species. We present evidence that the mechanisms associated with pulmonary hypertension are dependent on the type of stress to which the fetus is subjected. Such an analysis allows for a more thorough evaluation of the disease etiology, which can help focus clinical treatments. The final part of the review provides a clinical appraisal of current treatment strategies and lays the foundation for developing individualized therapies that depend on the causative factors.
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Affiliation(s)
- Demosthenes G Papamatheakis
- Division of Pulmonary and Critical Care, University of California San Diego Health System, San Diego, California, USA
| | - Madalitso Chundu
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Arlin B Blood
- Department of Pediatrics Division of Neonatology, and Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Sean M Wilson
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California, USA
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32
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Affiliation(s)
- Roxane Paulin
- From the Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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33
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Papamatheakis DG, Blood AB, Kim JH, Wilson SM. Antenatal hypoxia and pulmonary vascular function and remodeling. Curr Vasc Pharmacol 2014; 11:616-40. [PMID: 24063380 DOI: 10.2174/1570161111311050006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/25/2012] [Accepted: 07/12/2012] [Indexed: 01/02/2023]
Abstract
This review provides evidence that antenatal hypoxia, which represents a significant and worldwide problem, causes prenatal programming of the lung. A general overview of lung development is provided along with some background regarding transcriptional and signaling systems of the lung. The review illustrates that antenatal hypoxic stress can induce a continuum of responses depending on the species examined. Fetuses and newborns of certain species and specific human populations are well acclimated to antenatal hypoxia. However, antenatal hypoxia causes pulmonary vascular disease in fetuses and newborns of most mammalian species and humans. Disease can range from mild pulmonary hypertension, to severe vascular remodeling and dangerous elevations in pressure. The timing, length, and magnitude of the intrauterine hypoxic stress are important to disease development, however there is also a genetic-environmental relationship that is not yet completely understood. Determining the origins of pulmonary vascular remodeling and pulmonary hypertension and their associated effects is a challenging task, but is necessary in order to develop targeted therapies for pulmonary hypertension in the newborn due to antenatal hypoxia that can both treat the symptoms and curtail or reverse disease progression.
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Affiliation(s)
- Demosthenes G Papamatheakis
- Center for Perinatal Biology, Loma Linda University School of Medicine, 11234 Anderson Street, Loma Linda, 92350 CA, USA.
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34
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Meloche J, Pflieger A, Vaillancourt M, Paulin R, Potus F, Zervopoulos S, Graydon C, Courboulin A, Breuils-Bonnet S, Tremblay E, Couture C, Michelakis ED, Provencher S, Bonnet S. Role for DNA damage signaling in pulmonary arterial hypertension. Circulation 2013; 129:786-97. [PMID: 24270264 DOI: 10.1161/circulationaha.113.006167] [Citation(s) in RCA: 186] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is associated with sustained inflammation known to promote DNA damage. Despite these unfavorable environmental conditions, PAH pulmonary arterial smooth muscle cells (PASMCs) exhibit, in contrast to healthy PASMCs, a pro-proliferative and anti-apoptotic phenotype, sustained in time by the activation of miR-204, nuclear factor of activated T cells, and hypoxia-inducible factor 1-α. We hypothesized that PAH-PASMCs have increased the activation of poly(ADP-ribose) polymerase-1 (PARP-1), a critical enzyme implicated in DNA repair, allowing proliferation despite the presence of DNA-damaging insults, eventually leading to PAH. METHODS AND RESULTS Human PAH distal pulmonary arteries and cultured PAH-PASMCs exhibit increased DNA damage markers (53BP1 and γ-H2AX) and an overexpression of PARP-1 (immunoblot and activity assay), in comparison with healthy tissues/cells. Healthy PASMCs treated with a clinically relevant dose of tumor necrosis factor-α harbored a similar phenotype, suggesting that inflammation induces DNA damage and PARP-1 activation in PAH. We also showed that PARP-1 activation accounts for miR-204 downregulation (quantitative reverse transcription polymerase chain reaction) and the subsequent activation of the transcription factors nuclear factor of activated T cells and hypoxia-inducible factor 1-α in PAH-PASMCs, previously shown to be critical for PAH in several models. These effects resulted in PASMC proliferation (Ki67, proliferating cell nuclear antigen, and WST1 assays) and resistance to apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling and Annexin V assays). In vivo, the clinically available PARP inhibitor ABT-888 reversed PAH in 2 experimental rat models (Sugen/hypoxia and monocrotaline). CONCLUSIONS These results show for the first time that the DNA damage/PARP-1 signaling pathway is important for PAH development and provide a new therapeutic target for this deadly disease with high translational potential.
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Affiliation(s)
- Jolyane Meloche
- Department of Medicine, Laval University, Pulmonary Hypertension Research Group, IUCPQ Research Centre, Québec, Canada (J.M., A.P., M.V., F.P., C.G., A.C., S.B.-B., E.T., C.C., S.P., S.B.); and Vascular Biology Research Group, Department of Medicine, University of Alberta, Edmonton, Canada (R.P., S.Z., E.D.M.)
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Tajsic T, Morrell NW. Smooth muscle cell hypertrophy, proliferation, migration and apoptosis in pulmonary hypertension. Compr Physiol 2013; 1:295-317. [PMID: 23737174 DOI: 10.1002/cphy.c100026] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pulmonary hypertension is a multifactorial disease characterized by sustained elevation of pulmonary vascular resistance (PVR) and pulmonary arterial pressure (PAP). Central to the pathobiology of this disease is the process of vascular remodelling. This process involves structural and functional changes to the normal architecture of the walls of pulmonary arteries (PAs) that lead to increased muscularization of the muscular PAs, muscularization of the peripheral, previously nonmuscular, arteries of the respiratory acinus, formation of neointima, and formation of plexiform lesions. Underlying or contributing to the development of these lesions is hypertrophy, proliferation, migration, and resistance to apoptosis of medial cells and this article is concerned with the cellular and molecular mechanisms of these processes. In the first part of the article we focus on the concept of smooth muscle cell phenotype and the difficulties surrounding the identification and characterization of the cell/cells involved in the remodelling of the vessel media and we review the general mechanisms of cell hypertrophy, proliferation, migration and apoptosis. Then, in the larger part of the article, we review the factors identified thus far to be involved in PH intiation and/or progression and review and discuss their effects on pulmonary artery smooth muscle cells (PASMCs) the predominant cells in the tunica media of PAs.
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Affiliation(s)
- Tamara Tajsic
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
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36
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MicroRNAs in pulmonary arterial remodeling. Cell Mol Life Sci 2013; 70:4479-94. [PMID: 23739951 PMCID: PMC3827895 DOI: 10.1007/s00018-013-1382-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 05/20/2013] [Accepted: 05/22/2013] [Indexed: 12/12/2022]
Abstract
Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH.
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Matchkov VV, Secher Dam V, Bødtkjer DMB, Aalkjær C. Transport and Function of Chloride in Vascular Smooth Muscles. J Vasc Res 2013; 50:69-87. [DOI: 10.1159/000345242] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 10/16/2012] [Indexed: 12/12/2022] Open
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Circulating MMP-9 during exercise in humans. Eur J Appl Physiol 2012; 113:1249-55. [PMID: 23160657 DOI: 10.1007/s00421-012-2545-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 11/04/2012] [Indexed: 10/27/2022]
Abstract
Matrix metalloproteinase 9 (MMP-9) is a member of a family of zinc-dependent endopeptidases capable of degrading extracellular matrix (ECM) proteins. A single bout of exercise increases levels of activated MMP-9 in skeletal muscle and in the circulation. However, whether the exercise-induced activation of MMP-9 is associated with ECM remodeling and the cellular source behind MMP-9 in the circulation is not known. In the present study ten healthy male subjects performed a single cycle exercise bout and arterial and venous femoral blood was collected. To test if exercise induces basal lamina degradation and if circulating levels of MMP-9 is related to a release from the exercising muscle, arteriovenous differences of collagen IV and MMP-9 were measured by ELISA and zymography, respectively. Furthermore, markers of neutrophil degranulation elastase and neutrophil gelatinase-associated lipocalin (NGAL) were measured by ELISA. Plasma levels of collagen IV increased during the exercise bout and an increased arteriovenous difference of collagen IV was noted at 27 min of exercise. Plasma levels of MMP-9 were increased at both 27 and 57 min of exercise but no arteriovenous difference was noted. No changes over time were detected for elastase and NGAL. The observed release of collagen IV from the exercising muscle indicate basal lamina turnover following a single bout of exercise. No detectable release of MMP-9 was observed, suggesting that the increase in plasma MMP-9 could come from a source other than the skeletal muscle.
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Gatfield J, Mueller Grandjean C, Sasse T, Clozel M, Nayler O. Slow receptor dissociation kinetics differentiate macitentan from other endothelin receptor antagonists in pulmonary arterial smooth muscle cells. PLoS One 2012; 7:e47662. [PMID: 23077657 PMCID: PMC3471877 DOI: 10.1371/journal.pone.0047662] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/14/2012] [Indexed: 02/06/2023] Open
Abstract
Two endothelin receptor antagonists (ERAs), bosentan and ambrisentan, are currently approved for the treatment of pulmonary arterial hypertension (PAH), a devastating disease involving an activated endothelin system and aberrant contraction and proliferation of pulmonary arterial smooth muscle cells (PASMC). The novel ERA macitentan has recently concluded testing in a Phase III morbidity/mortality clinical trial in PAH patients. Since the association and dissociation rates of G protein-coupled receptor antagonists can influence their pharmacological activity in vivo, we used human PASMC to characterize inhibitory potency and receptor inhibition kinetics of macitentan, ambrisentan and bosentan using calcium release and inositol-1-phosphate (IP1) assays. In calcium release assays macitentan, ambrisentan and bosentan were highly potent ERAs with Kb values of 0.14 nM, 0.12 nM and 1.1 nM, respectively. Macitentan, but not ambrisentan and bosentan, displayed slow apparent receptor association kinetics as evidenced by increased antagonistic potency upon prolongation of antagonist pre-incubation times. In compound washout experiments, macitentan displayed a significantly lower receptor dissociation rate and longer receptor occupancy half-life (ROt1/2) compared to bosentan and ambrisentan (ROt1/2∶17 minutes versus 70 seconds and 40 seconds, respectively). Because of its lower dissociation rate macitentan behaved as an insurmountable antagonist in calcium release and IP1 assays, and unlike bosentan and ambrisentan it blocked endothelin receptor activation across a wide range of endothelin-1 (ET-1) concentrations. However, prolongation of the ET-1 stimulation time beyond ROt1/2 rendered macitentan a surmountable antagonist, revealing its competitive binding mode. Bosentan and ambrisentan behaved as surmountable antagonists irrespective of the assay duration and they lacked inhibitory activity at high ET-1 concentrations. Thus, macitentan is a competitive ERA with significantly slower receptor dissociation kinetics than the currently approved ERAs. Slow dissociation caused insurmountable antagonism in functional PASMC-based assays and this could contribute to an enhanced pharmacological activity of macitentan in ET-1-dependent pathologies.
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Affiliation(s)
- John Gatfield
- Actelion Pharmaceuticals Ltd., Allschwil, Switzerland.
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Wang J, Jiang Q, Wan L, Yang K, Zhang Y, Chen Y, Wang E, Lai N, Zhao L, Jiang H, Sun Y, Zhong N, Ran P, Lu W. Sodium tanshinone IIA sulfonate inhibits canonical transient receptor potential expression in pulmonary arterial smooth muscle from pulmonary hypertensive rats. Am J Respir Cell Mol Biol 2012; 48:125-34. [PMID: 23065131 DOI: 10.1165/rcmb.2012-0071oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Danshen, the dried root of Salvia miltiorrhiza, is widely used in clinics in China for treating various diseases, including cardiovascular diseases. Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA isolated as the major active component from Danshen, was recently reported to be effective in attenuating the characteristic pulmonary vascular changes associated with chronically hypoxic pulmonary hypertension (CHPH); however, the underlying detailed mechanisms are poorly understood. In this study, we investigated the effects of STS on basal intracellular Ca(2+) concentration ([Ca(2+)](i)) and store-operated Ca(2+) entry (SOCE) in distal pulmonary arterial smooth muscle cells (PASMCs) exposed to prolonged hypoxia or isolated from CHPH rats. SOCE measured by Mn(2+) quenching of Fura-2 fluorescence in PASMCs from rats exposed to chronic hypoxia (10% O(2), 21 d) was increased by 59%, and basal [Ca(2+)](i) was increased by 119%; this effect was inhibited by intraperitoneal injection of STS. These inhibitory effects of STS on hypoxic increases of SOCE and basal [Ca(2+)](i) were associated with reduced expression of canonical transient receptor potential (TRPC)1 and TRPC6 in distal pulmonary arterial smooth muscle and decreases on right ventricular pressure, right ventricular hypertrophy, and peripheral pulmonary vessel thickening. In ex vivo cultured distal PASMCs from normoxic rats, STS (0-25 μM) dose-dependently inhibited hypoxia-induced cell proliferation and migration, paralleled with attenuation in increases of basal [Ca(2+)](i), SOCE, mRNA, and protein expression of TRPC1 and TRPC6. STS also relieved right ventricular systolic pressure, right ventricular hypertrophy, and TRPC1 and TRPC6 protein expression in distal pulmonary arteries in a monocrotaline-induced rat model of pulmonary arterial hypertension. These results indicate that STS prevents pulmonary arterial hypertension development likely by inhibiting TRPC1 and TRPC6 expression, resulting in normalized basal [Ca(2+)](i) and attenuated proliferation and migration of PASMCs.
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Affiliation(s)
- Jian Wang
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China.
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Pathogenic role of store-operated and receptor-operated ca(2+) channels in pulmonary arterial hypertension. JOURNAL OF SIGNAL TRANSDUCTION 2012; 2012:951497. [PMID: 23056939 PMCID: PMC3465915 DOI: 10.1155/2012/951497] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/12/2012] [Accepted: 07/16/2012] [Indexed: 12/31/2022]
Abstract
Pulmonary circulation is an important circulatory system in which the body brings in oxygen. Pulmonary arterial hypertension (PAH) is a progressive and fatal disease that predominantly affects women. Sustained pulmonary vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness are the major causes for the elevated pulmonary vascular resistance (PVR) in patients with PAH. The elevated PVR causes an increase in afterload in the right ventricle, leading to right ventricular hypertrophy, right heart failure, and eventually death. Understanding the pathogenic mechanisms of PAH is important for developing more effective therapeutic approach for the disease. An increase in cytosolic free Ca2+ concentration ([Ca2+]cyt) in pulmonary arterial smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important stimulus for PASMC migration and proliferation which lead to pulmonary vascular wall thickening and remodeling. It is thus pertinent to define the pathogenic role of Ca2+ signaling in pulmonary vasoconstriction and PASMC proliferation to develop new therapies for PAH. [Ca2+]cyt in PASMC is increased by Ca2+ influx through Ca2+ channels in the plasma membrane and by Ca2+ release or mobilization from the intracellular stores, such as sarcoplasmic reticulum (SR) or endoplasmic reticulum (ER). There are two Ca2+ entry pathways, voltage-dependent Ca2+ influx through voltage-dependent Ca2+ channels (VDCC) and voltage-independent Ca2+ influx through store-operated Ca2+ channels (SOC) and receptor-operated Ca2+ channels (ROC). This paper will focus on the potential role of VDCC, SOC, and ROC in the development and progression of sustained pulmonary vasoconstriction and excessive pulmonary vascular remodeling in PAH.
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Effect of Yifei Huoxue Granule on the proliferation of rat pulmonary artery smooth muscle cells upon exposure to chronic hypoxic conditions in vitro. Chin J Integr Med 2012; 18:507-13. [PMID: 22772913 DOI: 10.1007/s11655-012-1150-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Indexed: 10/28/2022]
Abstract
OBJECTIVE To investigate the inhibitory effect of Yifei Huoxue Granule (, YFHXG) on the hypoxia-induced proliferation of rat pulmonary artery smooth muscle cells (PASMCs) and its mechanism of decreasing pulmonary arterial pressure. METHODS Twenty male Sprague-Dawley (SD) rats were randomly divided into four groups: saline, and 0.66, 3.30 and 16.50 g/kg of YFHXG groups, the saline and different concentrations of YFHXG were given twice daily for 7 days, respectively. Serum-pharmacology method was used in the preparation of YFHXG serum. Tissue block anchorage was employed in the primary culture of rat PASMCs. The PASMCs were randomly divided into normoxia group, hypoxia group, and hypoxia+YFHXG group (0.66, 3.30 and 16.50 g/kg doses of YFHXG-treated serum groups, exposed to hypoxic condition). PASMCs in normoxia and hypoxia group were cultured with saline serum, hypoxia+YFHXG groups were cultured with different concentrations of YFHXG serum. Cell viability was assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle was analyzed using flow cytometry. In addition, hypoxia inducible factor-1-alpha (HIF-1α) protein expression was evaluated by immunocytochemistry analysis, the concentration of intracellular reactive oxygen species (ROS) and Ca(2+) were determined by laser scanning confocal microscopy (LSCM). RESULTS MTT assay and flow cytometry showed that hypoxia could directly activate the proliferation of PASMCs, while YFHXG dose-dependently inhibited hypoxia-induced proliferation of rat PASMCs. Immunocytochemistry showed that hypoxia enhanced HIF-1α protein expression, and LSCM showed that hypoxia significantly increased intracellular ROS and Ca(2+), while YFHXG decreased the expression of HIF- 1α and attenuated the hypoxia-induced increase in intracellular concentration of ROS and Ca(2+). CONCLUSIONS YFHXG could inhibit hypoxia-induced proliferation of rat PASMCs, which may decrease pulmonary arterial pressure and vascular remodeling. The anti-hypoxia effect of YFHXG may be explained by its regulation of HIF-1α expression and of the levels of intracellular ROS and Ca(2+).
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Dai F, Mao Z, Xia J, Zhu S, Wu Z. Fluoxetine protects against big endothelin-1 induced anti-apoptosis by rescuing Kv1.5 channels in human pulmonary arterial smooth muscle cells. Yonsei Med J 2012; 53:842-8. [PMID: 22665355 PMCID: PMC3381489 DOI: 10.3349/ymj.2012.53.4.842] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Pulmonary Kv channels are thought to play a crucial role in the regulation of cell proliferation and apoptosis. Previous studies have shown that fluoxetine upregulated the expression of Kv1.5 and prevented pulmonary arterial hypertension in monocrotaline-induced or hypoxia-induced rats and mice. The current study was designed to test how fluoxetine regulates Kv1.5 channels, subsequently promoting apoptosis in human PASMCs cultured in vitro. MATERIALS AND METHODS Human PASMCs were incubated with low-serum DMEM, ET-1, and fluoxetine with and without ET-1 separately for 72 h. Then the proliferation, apoptosis, and expression of TRPC1 and Kv1.5 were detected. RESULTS In the ET-1 induced group, the upregulation of TRPC1 and down regulation of Kv1.5 enhanced proliferation and anti-apoptosis, which was reversed when treated with fluoxetine. The decreased expression of TRPC1 increased the expression of Kv1.5, subsequently inhibiting proliferation while promoting apoptosis. CONCLUSION The results from the present study suggested that fluoxetine protects against big endothelin-1 induced anti-apoptosis and rescues Kv1.5 channels in human pulmonary arterial smooth muscle cells, potentially by decreasing intracellular concentrations of Ca²⁺.
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Affiliation(s)
- FeiFeng Dai
- Department of Cardiothoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - ZhiFu Mao
- Department of Cardiothoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jun Xia
- Department of Cardiothoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - ShaoPing Zhu
- Department of Cardiothoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - ZhiYong Wu
- Department of Cardiothoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
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Sun H, Xia Y, Paudel O, Yang XR, Sham JSK. Chronic hypoxia-induced upregulation of Ca2+-activated Cl- channel in pulmonary arterial myocytes: a mechanism contributing to enhanced vasoreactivity. J Physiol 2012; 590:3507-21. [PMID: 22674716 DOI: 10.1113/jphysiol.2012.232520] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Chronic hypoxic pulmonary hypertension (CHPH) is associated with altered expression and function of cation channels in pulmonary arterial smooth muscle cells (PASMCs), but little is known for anion channels. The Ca(2+)-activated Cl(-) channel (CaCC), recently identified as TMEM16A, plays important roles in pulmonary vascular function. The present study sought to determine the effects of chronic hypoxia (CH) on the expression and function of CaCCs in PASMCs, and their contributions to the vascular hyperreactivity in CHPH. Male Wistar rats were exposed to room air or 10% O(2) for 3–4 weeks to generate CHPH. CaCC current (I(CI.Ca)) elicited by caffeine-induced Ca(2+) release or by depolarization at a constant high [Ca(2+)](i) (500 or 750 nm) was significantly larger in PASMCs of CH rats compared to controls. The enhanced I(CI.Ca)) density in CH PASMCs was unrelated to changes in amplitude of Ca(2+) release, Ca(2+)-dependent activation, voltage-dependent properties or calcineurin-dependent modulation of CaCCs, but was associated with increased TMEM16A mRNA and protein expression. Maximal contraction induced by serotonin, an important mediator of CHPH, was potentiated in endothelium-denuded pulmonary arteries of CH rats. The enhanced contractile response was prevented by the CaCC blockers niflumic acid and T16A(inh)-A01, or by the L-type Ca(2+) channel antagonist nifedipine. The effects of niflumic acid and nifedipine were non-additive. Our results demonstrate for the first time that CH increases I(CI.Ca) density, which is attributable to an upregulation of TMEM16A expression in PASMCs. The augmented CaCC activity in PASMCs may potentiate membrane depolarization and L-type channel activation in response to vasoconstrictors and enhance pulmonary vasoreactivity in CHPH.
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Affiliation(s)
- Hui Sun
- Division of Pulmonary and Critical Care Medicine, 5501, Hopkins Bayview Circle, Baltimore, MD 21224, USA
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Zhu D, Ran Y. Role of 15-lipoxygenase/15-hydroxyeicosatetraenoic acid in hypoxia-induced pulmonary hypertension. J Physiol Sci 2012; 62:163-72. [PMID: 22331435 PMCID: PMC10717549 DOI: 10.1007/s12576-012-0196-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/25/2012] [Indexed: 12/01/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a rare disease with a complex aetiology characterized by elevated pulmonary artery resistance, which leads to right heart ventricular afterload and ultimately progressing to right ventricular failure and often death. In addition to other factors, metabolites of arachidonic acid cascade play an important role in the pulmonary vasculature, and disruption of signaling pathways of arachidonic acid plays a central role in the pathogenesis of PAH. 15-Lipoxygenase (15-LO) is upregulated in pulmonary artery endothelial cells and smooth muscle cells of PAH patients, and its metabolite 15-hydroxyeicosatetraenoic acid (15-HETE) in particular seems to play a central role in the contractile machinery, and in the initiation and propagation of cell proliferation via its effects on signal pathways, mitogens, and cell cycle components. Here, we focus on our important research into the role played by 15-LO/15-HETE, which promotes a proliferative, antiapoptotic, and vasoconstrictive physiological milieu leading to hypoxic pulmonary hypertension.
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Affiliation(s)
- Daling Zhu
- College of Pharmacy, Harbin Medical University-Daqing, Daqing 163319, Heilongjiang, People's Republic of China.
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Kuhr FK, Smith KA, Song MY, Levitan I, Yuan JXJ. New mechanisms of pulmonary arterial hypertension: role of Ca²⁺ signaling. Am J Physiol Heart Circ Physiol 2012; 302:H1546-62. [PMID: 22245772 DOI: 10.1152/ajpheart.00944.2011] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a severe and progressive disease that usually culminates in right heart failure and death if left untreated. Although there have been substantial improvements in our understanding and significant advances in the management of this disease, there is a grim prognosis for patients in the advanced stages of PAH. A major cause of PAH is increased pulmonary vascular resistance, which results from sustained vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness. In addition to other signal transduction pathways, Ca(2+) signaling in pulmonary artery smooth muscle cells (PASMCs) plays a central role in the development and progression of PAH because of its involvement in both vasoconstriction, through its pivotal effect of PASMC contraction, and vascular remodeling, through its stimulatory effect on PASMC proliferation. Altered expression, function, and regulation of ion channels and transporters in PASMCs contribute to an increased cytosolic Ca(2+) concentration and enhanced Ca(2+) signaling in patients with PAH. This review will focus on the potential pathogenic role of Ca(2+) mobilization, regulation, and signaling in the development and progression of PAH.
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Affiliation(s)
- Frank K Kuhr
- Section of Pulmonary, Critical Care, Sleep, and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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Sutendra G, Dromparis P, Bonnet S, Haromy A, McMurtry MS, Bleackley RC, Michelakis ED. Pyruvate dehydrogenase inhibition by the inflammatory cytokine TNFα contributes to the pathogenesis of pulmonary arterial hypertension. J Mol Med (Berl) 2011; 89:771-83. [DOI: 10.1007/s00109-011-0762-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 03/21/2011] [Accepted: 04/11/2011] [Indexed: 12/18/2022]
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Courboulin A, Paulin R, Giguère NJ, Saksouk N, Perreault T, Meloche J, Paquet ER, Biardel S, Provencher S, Côté J, Simard MJ, Bonnet S. Role for miR-204 in human pulmonary arterial hypertension. ACTA ACUST UNITED AC 2011; 208:535-48. [PMID: 21321078 PMCID: PMC3058572 DOI: 10.1084/jem.20101812] [Citation(s) in RCA: 408] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Reduced miR-204 expression facilitates the excessive proliferation and apoptosis resistance of pulmonary artery smooth muscle cells characteristic of human pulmonary arterial hypertension. Pulmonary arterial hypertension (PAH) is characterized by enhanced proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs). Because microRNAs have been recently implicated in the regulation of cell proliferation and apoptosis, we hypothesized that these regulatory molecules might be implicated in the etiology of PAH. In this study, we show that miR-204 expression in PASMCs is down-regulated in both human and rodent PAH. miR-204 down-regulation correlates with PAH severity and accounts for the proliferative and antiapoptotic phenotypes of PAH-PASMCs. STAT3 activation suppresses miR-204 expression, and miR-204 directly targets SHP2 expression, thereby SHP2 up-regulation, by miR-204 down-regulation, activates the Src kinase and nuclear factor of activated T cells (NFAT). STAT3 also directly induces NFATc2 expression. NFAT and SHP2 were needed to sustain PAH-PASMC proliferation and resistance to apoptosis. Finally, delivery of synthetic miR-204 to the lungs of animals with PAH significantly reduced disease severity. This study uncovers a new regulatory pathway involving miR-204 that is critical to the etiology of PAH and indicates that reestablishing miR-204 expression should be explored as a potential new therapy for this disease.
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Affiliation(s)
- Audrey Courboulin
- Département de médecine, Faculté de médecine, Hôtel-Dieude Québec, Canada
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Song MY, Makino A, Yuan JXJ. STIM2 Contributes to Enhanced Store-operated Ca Entry in Pulmonary Artery Smooth Muscle Cells from Patients with Idiopathic Pulmonary Arterial Hypertension. Pulm Circ 2011; 1:84-94. [PMID: 21709766 PMCID: PMC3121304 DOI: 10.4103/2045-8932.78106] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pulmonary vasoconstriction and vascular remodeling are two major causes for elevated pulmonary vascular resistance and pulmonary arterial pressure in patients with idiopathic pulmonary arterial hypertension (IPAH). An increase in cytosolic free Ca2+concentration ([Ca2+]cyt) in pulmonary artery smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important stimulus for PASMC proliferation, which causes pulmonary vascular remodeling. Store-operated Ca2+ entry (SOCE), induced by depletion of stored Ca2+ in the sarcoplasmic reticulum (SR), can increase [Ca2+]cyt in PASMC, independent of other means of Ca2+ entry. Stromal interaction molecule (STIM) proteins, STIM1 and STIM2, were both recently identified as sensors for store depletion and also signaling molecules to open store-operated Ca2+ channels. We previously reported that SOCE was significantly enhanced in PASMC from IPAH patients compared to PASMC from normotensive control subjects. Enhanced SOCE plays an important role in the pathophysiological changes in PASMC associated with pulmonary arterial hypertension. In this study, we examine whether the expression levels of STIM1 and STIM2 are altered in IPAH-PASMC compared to control PASMC, and whether these putative changes in the STIM1 and STIM2 expression levels are responsible for enhanced SOCE and proliferation in IPAH-PASMC. Compared to control PASMC, the protein expression level of STIM2 was significantly increased in IPAH-PASMC, whereas STIM1 protein expression was not significantly changed. In IPAH-PASMC, the small interfering RNA (siRNA)-mediated knockdown of STIM2 decreased SOCE and proliferation, while knockdown of STIM2 in control PASMC had no effect on either SOCE or proliferation. Overexpression of STIM2 in the control PASMC failed to enhance SOCE or proliferation. These data indicate that enhanced protein expression of STIM2 is necessary, but not sufficient, for enhanced SOCE and proliferation of IPAH-PASMC.
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Affiliation(s)
- Michael Y Song
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093-0725
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50
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Firth AL, Remillard CV, Platoshyn O, Fantozzi I, Ko EA, Yuan JXJ. Functional ion channels in human pulmonary artery smooth muscle cells: Voltage-dependent cation channels. Pulm Circ 2011; 1:48-71. [PMID: 21927714 PMCID: PMC3173772 DOI: 10.4103/2045-8932.78103] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The activity of voltage-gated ion channels is critical for the maintenance of cellular membrane potential and generation of action potentials. In turn, membrane potential regulates cellular ion homeostasis, triggering the opening and closing of ion channels in the plasma membrane and, thus, enabling ion transport across the membrane. Such transmembrane ion fluxes are important for excitation–contraction coupling in pulmonary artery smooth muscle cells (PASMC). Families of voltage-dependent cation channels known to be present in PASMC include voltage-gated K+ (Kv) channels, voltage-dependent Ca2+-activated K+ (Kca) channels, L- and T- type voltage-dependent Ca2+ channels, voltage-gated Na+ channels and voltage-gated proton channels. When cells are dialyzed with Ca2+-free K+- solutions, depolarization elicits four components of 4-aminopyridine (4-AP)-sensitive Kvcurrents based on the kinetics of current activation and inactivation. In cell-attached membrane patches, depolarization elicits a wide range of single-channel K+ currents, with conductances ranging between 6 and 290 pS. Macroscopic 4-AP-sensitive Kv currents and iberiotoxin-sensitive Kca currents are also observed. Transcripts of (a) two Na+ channel α-subunit genes (SCN5A and SCN6A), (b) six Ca2+ channel α–subunit genes (α1A, α1B, α1X, α1D, α1Eand α1G) and many regulatory subunits (α2δ1, β1-4, and γ6), (c) 22 Kv channel α–subunit genes (Kv1.1 - Kv1.7, Kv1.10, Kv2.1, Kv3.1, Kv3.3, Kv3.4, Kv4.1, Kv4.2, Kv5.1, Kv 6.1-Kv6.3, Kv9.1, Kv9.3, Kv10.1 and Kv11.1) and three Kv channel β-subunit genes (Kvβ1-3) and (d) four Kca channel α–subunit genes (Sloα1 and SK2-SK4) and four Kca channel β-subunit genes (Kcaβ1-4) have been detected in PASMC. Tetrodotoxin-sensitive and rapidly inactivating Na+ currents have been recorded with properties similar to those in cardiac myocytes. In the presence of 20 mM external Ca2+, membrane depolarization from a holding potential of -100 mV elicits a rapidly inactivating T-type Ca2+ current, while depolarization from a holding potential of -70 mV elicits a slowly inactivating dihydropyridine-sensitive L-type Ca2+ current. This review will focus on describing the electrophysiological properties and molecular identities of these voltage-dependent cation channels in PASMC and their contribution to the regulation of pulmonary vascular function and its potential role in the pathogenesis of pulmonary vascular disease.
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Affiliation(s)
- Amy L Firth
- The Salk Institute for Biological Studies, La Jolla, California, USA
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