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Fang Q, Bai Y, Hu S, Ding J, Liu L, Dai M, Qiu J, Wu L, Rao X, Wang Y. Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling. Antioxidants (Basel) 2023; 12:1978. [PMID: 38001831 PMCID: PMC10669195 DOI: 10.3390/antiox12111978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/22/2023] [Accepted: 11/05/2023] [Indexed: 11/26/2023] Open
Abstract
Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.
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Affiliation(s)
- Qin Fang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yang Bai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Shuiqing Hu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Ding
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lei Liu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Meiyan Dai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Qiu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lujin Wu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoquan Rao
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
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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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Shimoda LA. Cellular Pathways Promoting Pulmonary Vascular Remodeling by Hypoxia. Physiology (Bethesda) 2021; 35:222-233. [PMID: 32490752 DOI: 10.1152/physiol.00039.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Exposure to hypoxia increases pulmonary vascular resistance, leading to elevated pulmonary arterial pressure and, potentially, right heart failure. Vascular remodeling is an important contributor to the increased pulmonary vascular resistance. Hyperproliferation of smooth muscle, endothelial cells, and fibroblasts, and deposition of extracellular matrix lead to increased wall thickness, extension of muscle into normally non-muscular arterioles, and vascular stiffening. This review highlights intrinsic and extrinsic modulators contributing to the remodeling process.
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Affiliation(s)
- Larissa A Shimoda
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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Redox and Inflammatory Signaling, the Unfolded Protein Response, and the Pathogenesis of Pulmonary Hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1304:333-373. [PMID: 34019276 DOI: 10.1007/978-3-030-68748-9_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Protein folding overload and oxidative stress disrupt endoplasmic reticulum (ER) homeostasis, generating reactive oxygen species (ROS) and activating the unfolded protein response (UPR). The altered ER redox state induces further ROS production through UPR signaling that balances the cell fates of survival and apoptosis, contributing to pulmonary microvascular inflammation and dysfunction and driving the development of pulmonary hypertension (PH). UPR-induced ROS production through ER calcium release along with NADPH oxidase activity results in endothelial injury and smooth muscle cell (SMC) proliferation. ROS and calcium signaling also promote endothelial nitric oxide (NO) synthase (eNOS) uncoupling, decreasing NO production and increasing vascular resistance through persistent vasoconstriction and SMC proliferation. C/EBP-homologous protein further inhibits eNOS, interfering with endothelial function. UPR-induced NF-κB activity regulates inflammatory processes in lung tissue and contributes to pulmonary vascular remodeling. Conversely, UPR-activated nuclear factor erythroid 2-related factor 2-mediated antioxidant signaling through heme oxygenase 1 attenuates inflammatory cytokine levels and protects against vascular SMC proliferation. A mutation in the bone morphogenic protein type 2 receptor (BMPR2) gene causes misfolded BMPR2 protein accumulation in the ER, implicating the UPR in familial pulmonary arterial hypertension pathogenesis. Altogether, there is substantial evidence that redox and inflammatory signaling associated with UPR activation is critical in PH pathogenesis.
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Wang M, Liu Y, Liang Y, Naruse K, Takahashi K. Systematic Understanding of Pathophysiological Mechanisms of Oxidative Stress-Related Conditions-Diabetes Mellitus, Cardiovascular Diseases, and Ischemia-Reperfusion Injury. Front Cardiovasc Med 2021; 8:649785. [PMID: 33928135 PMCID: PMC8076504 DOI: 10.3389/fcvm.2021.649785] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Reactive oxygen species (ROS) plays a role in intracellular signal transduction under physiological conditions while also playing an essential role in diseases such as hypertension, ischemic heart disease, and diabetes, as well as in the process of aging. The influence of ROS has some influence on the frequent occurrence of cardiovascular diseases (CVD) in diabetic patients. In this review, we considered the pathophysiological relationship between diabetes and CVD from the perspective of ROS. In addition, considering organ damage due to ROS elevation during ischemia-reperfusion, we discussed heart and lung injuries. Furthermore, we have focused on the transient receptor potential (TRP) channels and L-type calcium channels as molecular targets for ROS in ROS-induced tissue damages and have discussed about the pathophysiological mechanism of the injury.
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Affiliation(s)
| | | | | | | | - Ken Takahashi
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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Yan S, Resta TC, Jernigan NL. Vasoconstrictor Mechanisms in Chronic Hypoxia-Induced Pulmonary Hypertension: Role of Oxidant Signaling. Antioxidants (Basel) 2020; 9:E999. [PMID: 33076504 PMCID: PMC7602539 DOI: 10.3390/antiox9100999] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023] Open
Abstract
Elevated resistance of pulmonary circulation after chronic hypoxia exposure leads to pulmonary hypertension. Contributing to this pathological process is enhanced pulmonary vasoconstriction through both calcium-dependent and calcium sensitization mechanisms. Reactive oxygen species (ROS), as a result of increased enzymatic production and/or decreased scavenging, participate in augmentation of pulmonary arterial constriction by potentiating calcium influx as well as activation of myofilament sensitization, therefore mediating the development of pulmonary hypertension. Here, we review the effects of chronic hypoxia on sources of ROS within the pulmonary vasculature including NADPH oxidases, mitochondria, uncoupled endothelial nitric oxide synthase, xanthine oxidase, monoamine oxidases and dysfunctional superoxide dismutases. We also summarize the ROS-induced functional alterations of various Ca2+ and K+ channels involved in regulating Ca2+ influx, and of Rho kinase that is responsible for myofilament Ca2+ sensitivity. A variety of antioxidants have been shown to have beneficial therapeutic effects in animal models of pulmonary hypertension, supporting the role of ROS in the development of pulmonary hypertension. A better understanding of the mechanisms by which ROS enhance vasoconstriction will be useful in evaluating the efficacy of antioxidants for the treatment of pulmonary hypertension.
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Affiliation(s)
| | | | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA; (S.Y.); (T.C.R.)
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Zhang B, Zhang Y, Deng F, Fang S. Ligustrazine prevents basilar artery remodeling in two-kidney-two-clip renovascular hypertension rats via suppressing PI3K/Akt signaling. Microvasc Res 2019; 128:103938. [PMID: 31682800 DOI: 10.1016/j.mvr.2019.103938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/19/2019] [Accepted: 10/21/2019] [Indexed: 01/19/2023]
Abstract
OBJECTIVE In the present study, we used a two-kidney-two-clip (2k2c) stroke-prone renovascular hypertension rat model (RHRSP) to investigate the protective effects of ligustrazine (TMP) on cerebral arteries and to examine PI3K/Akt pathway behavior under this protection. METHODS The cerebral artery remodeling was induced by 2k2c-induced renovascular hypertension. Brain basilar artery tissues were isolated and their histological changes were detected through H&E and EVG staining, α-SMA IHC staining, and transmission electron microscopy at four, eight, and twelve weeks after 2k2c surgery, both with and without TMP treatment. Meanwhile, the ET-1, Ang II, and NO levels in basilar arteries and plasma were determined. Furthermore, the PTEN expression and the activation of PI3K/Akt in basilar artery tissues were detected through IHC and Western Blot. In addition, the primary basilar artery smooth muscle cells (BASMCs) were cultured and TMP protection of BASMCs stimulated with ET-1/Ang II in the presence or absence of insulin-like growth factor 1 (IGF-1) was determined. RESULTS TMP attenuated basilar artery remodeling, decreased ET-1 and Ang II levels and increased NO level in basilar arteries and plasma of RHRSP rats. Moreover, TMP reduced BASMCs proliferation upon ET-1/Ang II stimulation. We also found that TMP could effectively suppress the activation of PI3K/Akt in 2k2c-RHRSP rat basilar artery and ET-1/Ang II stimulated BASMCs. Most importantly, IGF-1, as an activator of PI3K/Akt, could damage the protective effect of TMP. CONCLUSIONS TMP exerts its protective effects and prevents basilar artery remodeling in RHRSP rats at least partly through the inhibition of PI3K/Akt pathway.
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MESH Headings
- Angiotensin II/metabolism
- Animals
- Cell Proliferation/drug effects
- Cells, Cultured
- Disease Models, Animal
- Endothelin-1/metabolism
- Hypertension, Renovascular/drug therapy
- Hypertension, Renovascular/enzymology
- Hypertension, Renovascular/pathology
- Hypertension, Renovascular/physiopathology
- Ligation
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/physiopathology
- Muscle, Smooth, Vascular/ultrastructure
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Nitric Oxide/metabolism
- Phosphatidylinositol 3-Kinase/metabolism
- Proto-Oncogene Proteins c-akt/metabolism
- Pyrazines/pharmacology
- Rats, Sprague-Dawley
- Renal Artery/surgery
- Signal Transduction
- Temporal Arteries/drug effects
- Temporal Arteries/enzymology
- Temporal Arteries/physiopathology
- Temporal Arteries/ultrastructure
- Vascular Remodeling/drug effects
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Affiliation(s)
- Beilin Zhang
- Department of Neurology, The First Teaching Hospital of Jilin University, Changchun, Jilin, China
| | - Ying Zhang
- Department of Neurology, The First Teaching Hospital of Jilin University, Changchun, Jilin, China
| | - Fang Deng
- Department of Neurology, The First Teaching Hospital of Jilin University, Changchun, Jilin, China
| | - Shaokuan Fang
- Department of Neurology, The First Teaching Hospital of Jilin University, Changchun, Jilin, China.
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Weise-Cross L, Resta TC, Jernigan NL. Redox Regulation of Ion Channels and Receptors in Pulmonary Hypertension. Antioxid Redox Signal 2019; 31:898-915. [PMID: 30569735 PMCID: PMC7061297 DOI: 10.1089/ars.2018.7699] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 12/11/2018] [Indexed: 02/06/2023]
Abstract
Significance: Pulmonary hypertension (PH) is characterized by elevated vascular resistance due to vasoconstriction and remodeling of the normally low-pressure pulmonary vasculature. Redox stress contributes to the pathophysiology of this disease by altering the regulation and activity of membrane receptors, K+ channels, and intracellular Ca2+ homeostasis. Recent Advances: Antioxidant therapies have had limited success in treating PH, leading to a growing appreciation that reductive stress, in addition to oxidative stress, plays a role in metabolic and cell signaling dysfunction in pulmonary vascular cells. Reactive oxygen species generation from mitochondria and NADPH oxidases has substantial effects on K+ conductance and membrane potential, and both receptor-operated and store-operated Ca2+ entry. Critical Issues: Some specific redox changes resulting from oxidation, S-nitrosylation, and S-glutathionylation are known to modulate membrane receptor and ion channel activity in PH. However, many sites of regulation that have been elucidated in nonpulmonary cell types have not been tested in the pulmonary vasculature, and context-specific molecular mechanisms are lacking. Future Directions: Here, we review what is known about redox regulation of membrane receptors and ion channels in PH. Further investigation of the mechanisms involved is needed to better understand the etiology of PH and develop better targeted treatment strategies.
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Affiliation(s)
- Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C. Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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Huetsch JC, Walker J, Undem C, Lade J, Yun X, Baksh S, Jiang H, Lai N, Shimoda LA. Rho kinase and Na + /H + exchanger mediate endothelin-1-induced pulmonary arterial smooth muscle cell proliferation and migration. Physiol Rep 2019; 6:e13698. [PMID: 29756391 PMCID: PMC5949284 DOI: 10.14814/phy2.13698] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 04/05/2018] [Accepted: 04/07/2018] [Indexed: 01/04/2023] Open
Abstract
Excessive production of endothelin‐1 (ET‐1) has been observed in almost all forms of pulmonary hypertension. ET‐1, a highly potent vasoconstrictor, can also potentiate pulmonary arterial smooth muscle cell (PASMC) growth and migration, both of which contribute to the vascular remodeling that occurs during the development of pulmonary hypertension. Increasing evidence indicates that alkalinization of intracellular pH (pHi), typically due to activation of Na+/H+ exchange (NHE), is associated with enhanced PASMC proliferation and migration. We recently demonstrated that application of exogenous ET‐1 increased NHE activity in murine PASMCs via a mechanism requiring Rho kinase (ROCK). However, whether ROCK and/or increased NHE activity mediate ET‐1‐induced migration and proliferation in PASMCs remains unknown. In this study, we used fluorescent microscopy in transiently cultured PASMCs from distal pulmonary arteries of the rat and the pH‐sensitive dye, BCECF‐AM, to measure changes in resting pHi and NHE activity induced by exposure to exogenous ET‐1 (10−8 mol/L) for 24 h. Cell migration and proliferation in response to ET‐1 were also measured using Transwell assays and BrdU incorporation, respectively. We found that application of exogenous ET‐1 had no effect on NHE1 expression, but increased pHi, NHE activity, migration, and proliferation in rat PASMCs. Pharmacologic inhibition of NHE or ROCK prevented the ET‐1‐induced changes in cell function (proliferation and migration). Our results indicate that ET‐1 modulates PASMC migration and proliferation via changes in pHi homeostasis through a pathway involving ROCK.
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Affiliation(s)
- John C Huetsch
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Jasmine Walker
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Clark Undem
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Julie Lade
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Xin Yun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Syeda Baksh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Ning Lai
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
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10
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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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11
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Weise-Cross L, Sands MA, Sheak JR, Broughton BRS, Snow JB, Gonzalez Bosc LV, Jernigan NL, Walker BR, Resta TC. Actin polymerization contributes to enhanced pulmonary vasoconstrictor reactivity after chronic hypoxia. Am J Physiol Heart Circ Physiol 2018; 314:H1011-H1021. [PMID: 29373038 DOI: 10.1152/ajpheart.00664.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Chronic hypoxia (CH) augments basal and endothelin-1 (ET-1)-induced pulmonary vasoconstrictor reactivity through reactive oxygen species (ROS) generation and RhoA/Rho kinase (ROCK)-dependent myofilament Ca2+ sensitization. Because ROCK promotes actin polymerization and the actin cytoskeleton regulates smooth muscle tension, we hypothesized that actin polymerization is required for enhanced basal and ET-1-dependent vasoconstriction after CH. To test this hypothesis, both end points were monitored in pressurized, endothelium-disrupted pulmonary arteries (fourth-fifth order) from control and CH (4 wk at 0.5 atm) rats. The actin polymerization inhibitors cytochalasin and latrunculin attenuated both basal and ET-1-induced vasoconstriction only in CH vessels. To test whether CH directly alters the arterial actin profile, we measured filamentous actin (F-actin)-to-globular actin (G-actin) ratios by fluorescent labeling of F-actin and G-actin in fixed pulmonary arteries and actin sedimentation assays using homogenized pulmonary artery lysates. We observed no difference in actin polymerization between groups under baseline conditions, but ET-1 enhanced actin polymerization in pulmonary arteries from CH rats. This response was blunted by the ROS scavenger tiron, the ROCK inhibitor fasudil, and the mDia (RhoA effector) inhibitor small-molecule inhibitor of formin homology domain 2. Immunoblot analysis revealed an effect of CH to increase both phosphorylated (inactive) and total levels of the actin disassembly factor cofilin but not phosphorylated cofilin-to-total cofilin ratios. We conclude that actin polymerization contributes to increased basal pulmonary arterial constriction and ET-1-induced vasoconstrictor reactivity after CH in a ROS- and ROCK-dependent manner. Our results further suggest that enhanced ET-1-mediated actin polymerization after CH is dependent on mDia but independent of changes in the phosphorylated cofilin-to-total cofilin ratio. NEW & NOTEWORTHY This research is the first to demonstrate a role for actin polymerization in chronic hypoxia-induced basal pulmonary arterial constriction and enhanced agonist-induced vasoconstrictor activity. These results suggest that a reactive oxygen species-Rho kinase-actin polymerization signaling pathway mediates this response and may provide a mechanistic basis for the vasoconstrictor component of pulmonary hypertension.
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Affiliation(s)
- Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Michelle A Sands
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Joshua R Sheak
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Brad R S Broughton
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Jessica B Snow
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Laura V Gonzalez Bosc
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Benjimen R Walker
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
| | - Thomas C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center , Albuquerque, New Mexico
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12
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Maron BA, Machado RF, Shimoda L. Pulmonary vascular and ventricular dysfunction in the susceptible patient (2015 Grover Conference series). Pulm Circ 2016; 6:426-438. [PMID: 28090285 PMCID: PMC5210067 DOI: 10.1086/688315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/21/2016] [Indexed: 12/14/2022] Open
Abstract
Pulmonary blood vessel structure and tone are maintained by a complex interplay between endogenous vasoactive factors and oxygen-sensing intermediaries. Under physiological conditions, these signaling networks function as an adaptive interface between the pulmonary circulation and environmental or acquired perturbations to preserve oxygenation and maintain systemic delivery of oxygen-rich hemoglobin. Chronic exposure to hypoxia, however, triggers a range of pathogenetic mechanisms that include hypoxia-inducible factor 1α (HIF-1α)-dependent upregulation of the vasoconstrictor peptide endothelin 1 in pulmonary endothelial cells. In pulmonary arterial smooth muscle cells, chronic hypoxia induces HIF-1α-mediated upregulation of canonical transient receptor potential proteins, as well as increased Rho kinase-Ca2+ signaling and pulmonary arteriole synthesis of the profibrotic hormone aldosterone. Collectively, these mechanisms contribute to a contractile or hypertrophic pulmonary vascular phenotype. Genetically inherited disorders in hemoglobin structure are also an important etiology of abnormal pulmonary vasoreactivity. In sickle cell anemia, for example, consumption of the vasodilator and antimitogenic molecule nitric oxide by cell-free hemoglobin is an important mechanism underpinning pulmonary hypertension. Contemporary genomic and transcriptomic analytic methods have also allowed for the discovery of novel risk factors relevant to sickle cell disease, including GALNT13 gene variants. In this report, we review cutting-edge observations characterizing these and other pathobiological mechanisms that contribute to pulmonary vascular and right ventricular vulnerability.
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Affiliation(s)
- Bradley A. Maron
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA; and Department of Cardiology, Boston Veterans Affairs Healthcare System, Boston, Massachusetts, USA
| | - Roberto F. Machado
- Division of Pulmonary, Critical Care Medicine, Sleep and Allergy, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Larissa Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Asthma and Allergy Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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13
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Abstract
The circulation of the lung is unique both in volume and function. For example, it is the only organ with two circulations: the pulmonary circulation, the main function of which is gas exchange, and the bronchial circulation, a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries and veins. The pulmonary circulation accommodates the entire cardiac output, maintaining high blood flow at low intravascular arterial pressure. As compared with the systemic circulation, pulmonary arteries have thinner walls with much less vascular smooth muscle and a relative lack of basal tone. Factors controlling pulmonary blood flow include vascular structure, gravity, mechanical effects of breathing, and the influence of neural and humoral factors. Pulmonary vascular tone is also altered by hypoxia, which causes pulmonary vasoconstriction. If the hypoxic stimulus persists for a prolonged period, contraction is accompanied by remodeling of the vasculature, resulting in pulmonary hypertension. In addition, genetic and environmental factors can also confer susceptibility to development of pulmonary hypertension. Under normal conditions, the endothelium forms a tight barrier, actively regulating interstitial fluid homeostasis. Infection and inflammation compromise normal barrier homeostasis, resulting in increased permeability and edema formation. This article focuses on reviewing the basics of the lung circulation (pulmonary and bronchial), normal development and transition at birth and vasoregulation. Mechanisms contributing to pathological conditions in the pulmonary circulation, in particular when barrier function is disrupted and during development of pulmonary hypertension, will also be discussed.
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Affiliation(s)
- Karthik Suresh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Larissa A. Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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14
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Li M, Li J, Meng G, Liu X. Protective effects of diltiazem against vascular endothelial cell injury induced by angiotensin-II and hypoxia. Clin Exp Pharmacol Physiol 2015; 42:337-43. [PMID: 25661249 DOI: 10.1111/1440-1681.12371] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/30/2014] [Accepted: 01/07/2015] [Indexed: 11/29/2022]
Abstract
To provide pharmacological data for future clinical studies, this study investigated the protective effects of diltiazem on vascular endothelial cell (VEC) injury induced by angiotensin-II (AngII), hypoxia, and a combination of both treatments. The concentration of intracellular free calcium and the mitochondrial membrane potential in VEC were assessed as indicators of cell injury. An in vivo hypoxic animal model was used to test the protective effect of diltiazem on vascular endothelial tissues. Our study showed that AngII and hypoxia decreased the mitochondrial membrane potential in VEC, which was significantly inhibited by diltiazem. Diltiazem protected against VEC injury induced by the increased concentration of intracellular free calcium, which was associated with AngII and hypoxia. Diltiazem reduced the apoptosis of rat VEC under a sustained hypoxic condition. In addition, it reduced AngII and endothelin I levels in rat vascular endothelial tissues. Our study confirmed that AngII and hypoxia induced VEC injury by regulating the levels of mitochondrial membrane potential and intracellular free calcium. Diltiazem, a calcium channel blocker, protected VEC from AngII- and hypoxia-induced injury.
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Affiliation(s)
- Minggao Li
- Aviation and Diving Medical Center, Navy General Hospital, Beijing, China
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15
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Jernigan NL, Resta TC. Calcium Homeostasis and Sensitization in Pulmonary Arterial Smooth Muscle. Microcirculation 2014; 21:259-71. [DOI: 10.1111/micc.12096] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/25/2013] [Indexed: 01/10/2023]
Affiliation(s)
- Nikki L. Jernigan
- Vascular Physiology Group; Department of Cell Biology and Physiology; University of New Mexico Health Sciences Center; Albuquerque New Mexico USA
| | - Thomas C. Resta
- Vascular Physiology Group; Department of Cell Biology and Physiology; University of New Mexico Health Sciences Center; Albuquerque New Mexico USA
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16
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Vascular remodeling in pulmonary hypertension. J Mol Med (Berl) 2013; 91:297-309. [PMID: 23334338 DOI: 10.1007/s00109-013-0998-0] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/04/2013] [Accepted: 01/08/2013] [Indexed: 02/07/2023]
Abstract
Pulmonary hypertension is a complex, progressive condition arising from a variety of genetic and pathogenic causes. Patients present with a spectrum of histologic and pathophysiological features, likely reflecting the diversity in underlying pathogenesis. It is widely recognized that structural alterations in the vascular wall contribute to all forms of pulmonary hypertension. Features characteristic of the remodeled vasculature in patients with pulmonary hypertension include increased stiffening of the elastic proximal pulmonary arteries, thickening of the intimal and/or medial layer of muscular arteries, development of vaso-occlusive lesions, and the appearance of cells expressing smooth muscle-specific markers in normally non-muscular small diameter vessels, resulting from proliferation and migration of pulmonary arterial smooth muscle cells and cellular transdifferentiation. The development of several animal models of pulmonary hypertension has provided the means to explore the mechanistic underpinnings of pulmonary vascular remodeling, although none of the experimental models currently used entirely replicates the pulmonary arterial hypertension observed in patients. Herein, we provide an overview of the histological abnormalities observed in humans with pulmonary hypertension and in preclinical models and discuss insights gained regarding several key signaling pathways contributing to the remodeling process. In particular, we will focus on the roles of ion homeostasis, endothelin-1, serotonin, bone morphogenetic proteins, Rho kinase, and hypoxia-inducible factor 1 in pulmonary arterial smooth muscle and endothelial cells, highlighting areas of cross-talk between these pathways and potentials for therapeutic targeting.
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17
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De La Vega-Beltran JL, Sánchez-Cárdenas C, Krapf D, Hernandez-González EO, Wertheimer E, Treviño CL, Visconti PE, Darszon A. Mouse sperm membrane potential hyperpolarization is necessary and sufficient to prepare sperm for the acrosome reaction. J Biol Chem 2012; 287:44384-93. [PMID: 23095755 DOI: 10.1074/jbc.m112.393488] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mammalian sperm are unable to fertilize the egg immediately after ejaculation; they acquire this capacity during migration in the female reproductive tract. This maturational process is called capacitation and in mouse sperm it involves a plasma membrane reorganization, extensive changes in the state of protein phosphorylation, increases in intracellular pH (pH(i)) and Ca(2+) ([Ca(2+)](i)), and the appearance of hyperactivated motility. In addition, mouse sperm capacitation is associated with the hyperpolarization of the cell membrane potential. However, the functional role of this process is not known. In this work, to dissect the role of this membrane potential change, hyperpolarization was induced in noncapacitated sperm using either the ENaC inhibitor amiloride, the CFTR agonist genistein or the K(+) ionophore valinomycin. In this experimental setting, other capacitation-associated processes such as activation of a cAMP-dependent pathway and the consequent increase in protein tyrosine phosphorylation were not observed. However, hyperpolarization was sufficient to prepare sperm for the acrosome reaction induced either by depolarization with high K(+) or by addition of solubilized zona pellucida (sZP). Moreover, K(+) and sZP were also able to increase [Ca(2+)](i) in non-capacitated sperm treated with these hyperpolarizing agents but not in untreated cells. On the other hand, in conditions that support capacitation-associated processes blocking hyperpolarization by adding valinomycin and increasing K(+) concentrations inhibited the agonist-induced acrosome reaction as well as the increase in [Ca(2+)](i). Altogether, these results suggest that sperm hyperpolarization by itself is key to enabling mice sperm to undergo the acrosome reaction.
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Affiliation(s)
- Jose Luis De La Vega-Beltran
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
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18
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Undem C, Rios EJ, Maylor J, Shimoda LA. Endothelin-1 augments Na⁺/H⁺ exchange activity in murine pulmonary arterial smooth muscle cells via Rho kinase. PLoS One 2012; 7:e46303. [PMID: 23029469 PMCID: PMC3460862 DOI: 10.1371/journal.pone.0046303] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 08/29/2012] [Indexed: 12/20/2022] Open
Abstract
Excessive production of endothelin-1 (ET-1), a potent vasoconstrictor, occurs with several forms of pulmonary hypertension. In addition to modulating vasomotor tone, ET-1 can potentiate pulmonary arterial smooth muscle cell (PASMC) growth and migration, both of which contribute to the vascular remodeling that occurs during the development of pulmonary hypertension. It is well established that changes in cell proliferation and migration in PASMCs are associated with alkalinization of intracellular pH (pHi), typically due to activation of Na+/H+ exchange (NHE). In the systemic vasculature, ET-1 increases pHi, Na+/H+ exchange activity and stimulates cell growth via a mechanism dependent on protein kinase C (PKC). These results, coupled with data describing elevated levels of ET-1 in hypertensive animals/humans, suggest that ET-1 may play an important role in modulating pHi and smooth muscle growth in the lung; however, the effect of ET-1 on basal pHi and NHE activity has yet to be examined in PASMCs. Thus, we used fluorescent microscopy in transiently (3–5 days) cultured rat PASMCs and the pH-sensitive dye, BCECF-AM, to measure changes in basal pHi and NHE activity induced by increasing concentrations of ET-1 (10−10 to 10−8 M). We found that application of exogenous ET-1 increased pHi and NHE activity in PASMCs and that the ET-1-induced augmentation of NHE was prevented in PASMCs pretreated with an inhibitor of Rho kinase, but not inhibitors of PKC. Moreover, direct activation of PKC had no effect on pHi or NHE activity in PASMCs. Our results indicate that ET-1 can modulate pH homeostasis in PASMCs via a signaling pathway that includes Rho kinase and that, in contrast to systemic vascular smooth muscle, activation of PKC does not appear to be an important regulator of PASMC pHi.
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MESH Headings
- Animals
- Cells, Cultured
- Dose-Response Relationship, Drug
- Endothelin-1/pharmacology
- Enzyme Activation/drug effects
- Fluoresceins
- Fluorescent Dyes
- Hydrogen-Ion Concentration
- Male
- Mice
- Mice, Inbred C57BL
- Microscopy, Fluorescence
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Protein Kinase C/metabolism
- Protein Kinase Inhibitors/pharmacology
- Pulmonary Artery/cytology
- Pulmonary Artery/drug effects
- Pulmonary Artery/enzymology
- Signal Transduction/drug effects
- Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors
- Sodium-Potassium-Exchanging ATPase/metabolism
- rho-Associated Kinases/antagonists & inhibitors
- rho-Associated Kinases/metabolism
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Affiliation(s)
- Clark Undem
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Eon J. Rios
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Julie Maylor
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Larissa A. Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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