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Ji HL, Zhao R, Matalon S, Matthay MA. Elevated Plasmin(ogen) as a Common Risk Factor for COVID-19 Susceptibility. Physiol Rev 2020; 100:1065-1075. [PMID: 32216698 PMCID: PMC7191627 DOI: 10.1152/physrev.00013.2020] [Citation(s) in RCA: 257] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 01/08/2023] Open
Abstract
Patients with hypertension, diabetes, coronary heart disease, cerebrovascular illness, chronic obstructive pulmonary disease, and kidney dysfunction have worse clinical outcomes when infected with SARS-CoV-2, for unknown reasons. The purpose of this review is to summarize the evidence for the existence of elevated plasmin(ogen) in COVID-19 patients with these comorbid conditions. Plasmin, and other proteases, may cleave a newly inserted furin site in the S protein of SARS-CoV-2, extracellularly, which increases its infectivity and virulence. Hyperfibrinolysis associated with plasmin leads to elevated D-dimer in severe patients. The plasmin(ogen) system may prove a promising therapeutic target for combating COVID-19.
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Affiliation(s)
- Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas Health Science Centre at Tyler, Tyler, Texas; Texas Lung Injury Institute, University of Texas Health Science Centre at Tyler, Tyler, Texas; Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine, Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and Department of Medicine and Anesthesia, University of California San Francisco, San Francisco, California
| | - Runzhen Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Centre at Tyler, Tyler, Texas; Texas Lung Injury Institute, University of Texas Health Science Centre at Tyler, Tyler, Texas; Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine, Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and Department of Medicine and Anesthesia, University of California San Francisco, San Francisco, California
| | - Sadis Matalon
- Department of Cellular and Molecular Biology, University of Texas Health Science Centre at Tyler, Tyler, Texas; Texas Lung Injury Institute, University of Texas Health Science Centre at Tyler, Tyler, Texas; Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine, Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and Department of Medicine and Anesthesia, University of California San Francisco, San Francisco, California
| | - Michael A Matthay
- Department of Cellular and Molecular Biology, University of Texas Health Science Centre at Tyler, Tyler, Texas; Texas Lung Injury Institute, University of Texas Health Science Centre at Tyler, Tyler, Texas; Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine, Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and Department of Medicine and Anesthesia, University of California San Francisco, San Francisco, California
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The Role of MicroRNA in the Airway Surface Liquid Homeostasis. Int J Mol Sci 2020; 21:ijms21113848. [PMID: 32481719 PMCID: PMC7312818 DOI: 10.3390/ijms21113848] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/24/2020] [Accepted: 05/25/2020] [Indexed: 02/06/2023] Open
Abstract
Mucociliary clearance, mediated by a coordinated function of cilia bathing in the airway surface liquid (ASL) on the surface of airway epithelium, protects the host from inhaled pathogens and is an essential component of the innate immunity. ASL is composed of the superficial mucus layer and the deeper periciliary liquid. Ion channels, transporters, and pumps coordinate the transcellular and paracellular movement of ions and water to maintain the ASL volume and mucus hydration. microRNA (miRNA) is a class of non-coding, short single-stranded RNA regulating gene expression by post-transcriptional mechanisms. miRNAs have been increasingly recognized as essential regulators of ion channels and transporters responsible for ASL homeostasis. miRNAs also influence the airway host defense. We summarize the most up-to-date information on the role of miRNAs in ASL homeostasis and host-pathogen interactions in the airway and discuss concepts for miRNA-directed therapy.
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Abstract
PURPOSE OF REVIEW This review summarizes current understanding of the pathophysiology of cardiogenic pulmonary edema, its causes and treatment. RECENT FINDINGS The pathobiology and classification of pulmonary edema is more complex than the hydrostatic vs. permeability dichotomy of the past. Mechanisms of alveolar fluid clearance and factors that affect the clearance rate are under intensive study to find therapeutic strategies. Patients need early stabilization of oxygenation and ventilation, preferably with high-flow nasal cannula oxygen or noninvasive ventilation whereas the diagnostic cause is quickly sought with echocardiography and other testing. SUMMARY Treatments must be initiated early, whereas evaluation still is occurring and requires multimodality intervention. The general treatment of cardiogenic pulmonary edema includes diuretics, possibly morphine and often nitrates. The appropriate use of newer approaches - such as, nesiritide, high-dose vasodilators, milrinone, and vasopressin receptor antagonists - needs larger clinical trials.
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Lipopolysaccharide Inhibits Alpha Epithelial Sodium Channel Expression via MiR-124-5p in Alveolar Type 2 Epithelial Cells. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8150780. [PMID: 32190682 PMCID: PMC7072113 DOI: 10.1155/2020/8150780] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 01/19/2020] [Accepted: 01/30/2020] [Indexed: 01/09/2023]
Abstract
Mesenchymal stem cells (MSCs) have been a potential strategy in the pretreatment of pulmonary diseases, while the mechanisms of MSCs-conditioned medium (MSCs-CM) involved with microRNAs on the regulation of lung ion transport are seldom reported. We investigated the role of miR-124-5p in lipopolysaccharide-involved epithelial sodium channel (ENaC) dysfunction and explored the potential target of miR-124-5p. We observed the lower expression of miR-124-5p after the administration of MSCs-CM, and the overexpression or inhibition of miR-124-5p regulated epithelial sodium channel α-subunit (α-ENaC) expression at protein levels in mouse alveolar type 2 epithelial (AT2) cells. We confirmed that α-ENaC is one of the target genes of miR-124-5p through dual luciferase assay and Ussing chamber assay revealed that miR-124-5p inhibited amiloride-sensitive currents associated with ENaC activity in intact H441 monolayers. Our results demonstrate that miR-124-5p can decrease the expression and function of α-ENaC in alveolar epithelial cells by targeting the 3'-UTR. The involvement of MSCs-CM in lipopolysaccharide-induced acute lung injury cell model could be related to the downregulation of miR-124-5p on α-ENaC, which may provide a new target for the treatment of acute lung injury.
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55
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Restrepo-Angulo I, Bañuelos C, Camacho J. Ion Channel Regulation by Sex Steroid Hormones and Vitamin D in Cancer: A Potential Opportunity for Cancer Diagnosis and Therapy. Front Pharmacol 2020; 11:152. [PMID: 32210800 PMCID: PMC7076584 DOI: 10.3389/fphar.2020.00152] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/05/2020] [Indexed: 12/24/2022] Open
Abstract
Many ion channels are involved in tumor development, promoting cancer cell proliferation, migration, invasion, and survival. Accordingly, some of them have been suggested as tumor markers and novel targets for cancer therapy. Some sex steroid hormones (SSH), including estrogens and androgens, favor cancer progression. Meanwhile, other steroid hormones like vitamin D may have anticancer properties. SSH and vitamin D modulate the expression of a number of ion channels in cancer cells from hormone-sensitive tissues, including breast, ovary, prostate, and cervix. Moreover, rapid effects of SSH may be mediated by their direct action on membrane ion channels. Here, we reviewed the SSH and vitamin D regulation of ion channels involved in cancer, and analyzed the potential molecular pathways implicated. In addition, we described the potential clinical use of ion channels in cancer diagnosis and therapy, taking advantage of their regulation by SSH and vitamin D. Since SSH are considered risk factors for different types of cancer, and ion channels play important roles in tumor progression, the regulation of ion channels by SSH and vitamin D may represent a potential opportunity for early cancer diagnosis and therapeutic approaches in SSH and vitamin D sensitive tumors.
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Affiliation(s)
- Iván Restrepo-Angulo
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Cecilia Bañuelos
- Transdisciplinary Program on Science, Technology and Society, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Javier Camacho
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
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An outlined review for the role of Nedd4-1 and Nedd4-2 in lung disorders. Biomed Pharmacother 2020; 125:109983. [PMID: 32092816 DOI: 10.1016/j.biopha.2020.109983] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 12/16/2022] Open
Abstract
Neural precursor cell expressed, developmentally down-regulated 4, E3 ubiquitin protein ligase (Nedd4-1 and Nedd4-2) is a member of the HECT E3 ubiquitin ligase family. It has been shown to mediate numerous pathophysiological processes, including the regulation of synaptic plasticity and Wnt-associated signaling, via promoting the ubiquitination of its substrates, such as cyclic adenosine monophosphate (cAMP)-response element binding protein regulated transcription coactivator 3 (CRTC3), alpha-amino-3-hydroxy-5-methyl-4-isoxazo-lepropionic acid receptor (AMPAR), and Dishevelled2 (Dvl2). In the respiratory system, both Nedd4-1 and Nedd4-2 are expressed in epithelial cells and functionally associated with lung cancer development and alveolar fluid regulation. Nedd4-1 mediates lung cancer migration, metastasis, or drug resistance mainly through inducing phosphate and tension homology deleted on chromsome ten (PTEN) degradation or promoting cathepsin B secretion. Unlike Nedd4-1, Nedd4-2 displays more complex effects in lung cancers. On one hand it suppresses lung cancer cell migration and metastasis, and on the other hand it has been shown to promote lung cancer survival via inducing general control nonrepressed 2 (GCN2) degradation. Another important function of Nedd4-2 is to regulate the activity of epithelial sodium channel (ENaC), a membrane channel which mediates the clearance of fluid from the alveolar space at birth or during pulmonary edema. Here, we make an outlined review for the expression and function of Nedd4-1 and Nedd4-2 in the respiratory system in hope of getting an in-depth insight into their roles in lung disorders.
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Kryvenko V, Wessendorf M, Morty RE, Herold S, Seeger W, Vagin O, Dada LA, Sznajder JI, Vadász I. Hypercapnia Impairs Na,K-ATPase Function by Inducing Endoplasmic Reticulum Retention of the β-Subunit of the Enzyme in Alveolar Epithelial Cells. Int J Mol Sci 2020; 21:E1467. [PMID: 32098115 PMCID: PMC7073107 DOI: 10.3390/ijms21041467] [Citation(s) in RCA: 12] [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: 02/03/2020] [Revised: 02/16/2020] [Accepted: 02/17/2020] [Indexed: 01/02/2023] Open
Abstract
Alveolar edema, impaired alveolar fluid clearance, and elevated CO2 levels (hypercapnia) are hallmarks of the acute respiratory distress syndrome (ARDS). This study investigated how hypercapnia affects maturation of the Na,K-ATPase (NKA), a key membrane transporter, and a cell adhesion molecule involved in the resolution of alveolar edema in the endoplasmic reticulum (ER). Exposure of human alveolar epithelial cells to elevated CO2 concentrations caused a significant retention of NKA-β in the ER and, thus, decreased levels of the transporter in the Golgi apparatus. These effects were associated with a marked reduction of the plasma membrane (PM) abundance of the NKA-α/β complex as well as a decreased total and ouabain-sensitive ATPase activity. Furthermore, our study revealed that the ER-retained NKA-β subunits were only partially assembled with NKA α-subunits, which suggests that hypercapnia modifies the ER folding environment. Moreover, we observed that elevated CO2 levels decreased intracellular ATP production and increased ER protein and, particularly, NKA-β oxidation. Treatment with α-ketoglutaric acid (α-KG), which is a metabolite that has been shown to increase ATP levels and rescue mitochondrial function in hypercapnia-exposed cells, attenuated the deleterious effects of elevated CO2 concentrations and restored NKA PM abundance and function. Taken together, our findings provide new insights into the regulation of NKA in alveolar epithelial cells by elevated CO2 levels, which may lead to the development of new therapeutic approaches for patients with ARDS and hypercapnia.
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Affiliation(s)
- Vitalii Kryvenko
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), 35392 Giessen, Germany; (V.K.); (M.W.); (R.E.M.); (S.H.); (W.S.)
- The Cardio-Pulmonary Institute (CPI), 35392 Giessen, Germany
| | - Miriam Wessendorf
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), 35392 Giessen, Germany; (V.K.); (M.W.); (R.E.M.); (S.H.); (W.S.)
| | - Rory E. Morty
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), 35392 Giessen, Germany; (V.K.); (M.W.); (R.E.M.); (S.H.); (W.S.)
- The Cardio-Pulmonary Institute (CPI), 35392 Giessen, Germany
- Department of Lung Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Susanne Herold
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), 35392 Giessen, Germany; (V.K.); (M.W.); (R.E.M.); (S.H.); (W.S.)
- The Cardio-Pulmonary Institute (CPI), 35392 Giessen, Germany
| | - Werner Seeger
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), 35392 Giessen, Germany; (V.K.); (M.W.); (R.E.M.); (S.H.); (W.S.)
- The Cardio-Pulmonary Institute (CPI), 35392 Giessen, Germany
- Department of Lung Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Olga Vagin
- Department of Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA;
- Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Laura A. Dada
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (L.A.D.); (J.I.S.)
| | - Jacob I. Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; (L.A.D.); (J.I.S.)
| | - István Vadász
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), 35392 Giessen, Germany; (V.K.); (M.W.); (R.E.M.); (S.H.); (W.S.)
- The Cardio-Pulmonary Institute (CPI), 35392 Giessen, Germany
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LeMessurier KS, Tiwary M, Morin NP, Samarasinghe AE. Respiratory Barrier as a Safeguard and Regulator of Defense Against Influenza A Virus and Streptococcus pneumoniae. Front Immunol 2020; 11:3. [PMID: 32117216 PMCID: PMC7011736 DOI: 10.3389/fimmu.2020.00003] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/03/2020] [Indexed: 12/27/2022] Open
Abstract
The primary function of the respiratory system of gas exchange renders it vulnerable to environmental pathogens that circulate in the air. Physical and cellular barriers of the respiratory tract mucosal surface utilize a variety of strategies to obstruct microbe entry. Physical barrier defenses including the surface fluid replete with antimicrobials, neutralizing immunoglobulins, mucus, and the epithelial cell layer with rapidly beating cilia form a near impenetrable wall that separates the external environment from the internal soft tissue of the host. Resident leukocytes, primarily of the innate immune branch, also maintain airway integrity by constant surveillance and the maintenance of homeostasis through the release of cytokines and growth factors. Unfortunately, pathogens such as influenza virus and Streptococcus pneumoniae require hosts for their replication and dissemination, and prey on the respiratory tract as an ideal environment causing severe damage to the host during their invasion. In this review, we outline the host-pathogen interactions during influenza and post-influenza bacterial pneumonia with a focus on inter- and intra-cellular crosstalk important in pulmonary immune responses.
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Affiliation(s)
- Kim S LeMessurier
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Division of Pulmonology, Allergy-Immunology, and Sleep, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, Children's Foundation Research Institute, Memphis, TN, United States
| | - Meenakshi Tiwary
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Division of Pulmonology, Allergy-Immunology, and Sleep, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, Children's Foundation Research Institute, Memphis, TN, United States
| | - Nicholas P Morin
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Division of Critical Care Medicine, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Amali E Samarasinghe
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Division of Pulmonology, Allergy-Immunology, and Sleep, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, Children's Foundation Research Institute, Memphis, TN, United States
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Singh S, Lumbreras-Marquez MI, Farber MK, Xu X, Singh P, Gorman T, Palanisamy A. Transient Tachypnea of Newborns Is Associated With Maternal Spinal Hypotension During Elective Cesarean Delivery: A Retrospective Cohort Study. Anesth Analg 2020; 129:162-167. [PMID: 30768454 DOI: 10.1213/ane.0000000000004064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND The risk for transient tachypnea of newborns, a common cause of respiratory distress in the neonatal period, is 2- to 6-fold higher during elective cesarean delivery compared to vaginal delivery. Here, we evaluated the association between transient tachypnea of newborns and the degree and duration of predelivery maternal hypotension during spinal anesthesia for elective cesarean delivery. METHODS Demographic data, details of anesthetic management, blood pressure measurements, and vasopressor requirement preceding delivery were compared between transient tachypnea newborns (n = 30) and healthy neonates (n = 151) with normal respiratory function born via elective cesarean delivery between July 2015 and February 2016. The degree and duration of hypotension were assessed using area under the curve for systolic blood pressure (SBP) ≤90 mm Hg and area under the curve for mean arterial pressure ≤65 mm Hg. After adjusting for confounders, multivariable logistic regression was used to evaluate the association between area under the curve for SBP and transient tachypnea of newborns. RESULTS The median area under the curve for SBP was higher in cases of transient tachypnea of newborns (0.94; interquartile range, 0-28.7 mm Hg*min) compared to healthy controls (0; interquartile range, 0-3.30 mm Hg*min; P = .001). Similarly, median area under the curve for mean arterial pressure was also higher in cases of transient tachypnea of newborns (0; interquartile range, 0-18.6 mm Hg*min) compared to controls (0; interquartile range, 0-1.1 mm Hg*min; P = .01). Mothers of transient tachypnea newborns received significantly higher amounts of phenylephrine and ephedrine compared to controls (P = .001 and 0.01, respectively). Hence, the total vasopressor dose given to mothers in the transient tachypnea of newborn group was much higher than for the control group (P = .001). In the multivariable logistic regression, area under the curve for SBP was significantly associated with transient tachypnea of newborns (odds ratio, 1.02; 95% CI, 1.01-1.04, P = .005) after adjusting for gravidity and the type of anesthetic (spinal versus combined spinal epidural). CONCLUSIONS Our results suggest that the degree and duration of maternal SBP <90 mm Hg after neuraxial anesthesia during elective cesarean delivery are associated with transient tachypnea of newborns. Future prospective studies should further explore the effects of maternal hypotension, its prevention, and treatment for transient tachypnea of newborns.
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Affiliation(s)
- Shubhangi Singh
- From the Department of Anesthesiology and Critical Care, Brigham and Women's Hospital, Boston, Massachusetts
| | | | - Michaela K Farber
- From the Department of Anesthesiology and Critical Care, Brigham and Women's Hospital, Boston, Massachusetts
| | - Xinling Xu
- From the Department of Anesthesiology and Critical Care, Brigham and Women's Hospital, Boston, Massachusetts
| | - Prashant Singh
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Terri Gorman
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - Arvind Palanisamy
- Department of Anesthesiology, Washington University, St Louis, Missouri
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Kleyman TR, Eaton DC. Regulating ENaC's gate. Am J Physiol Cell Physiol 2020; 318:C150-C162. [PMID: 31721612 PMCID: PMC6985836 DOI: 10.1152/ajpcell.00418.2019] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 02/07/2023]
Abstract
Epithelial Na+ channels (ENaCs) are members of a family of cation channels that function as sensors of the extracellular environment. ENaCs are activated by specific proteases in the biosynthetic pathway and at the cell surface and remove embedded inhibitory tracts, which allows channels to transition to higher open-probability states. Resolved structures of ENaC and an acid-sensing ion channel revealed highly organized extracellular regions. Within the periphery of ENaC subunits are unique domains formed by antiparallel β-strands containing the inhibitory tracts and protease cleavage sites. ENaCs are inhibited by Na+ binding to specific extracellular site(s), which promotes channel transition to a lower open-probability state. Specific inositol phospholipids and channel modification by Cys-palmitoylation enhance channel open probability. How these regulatory factors interact in a concerted manner to influence channel open probability is an important question that has not been resolved. These various factors are reviewed, and the impact of specific factors on human disorders is discussed.
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Affiliation(s)
- Thomas R Kleyman
- Renal-Electrolyte Division, Department of Medicine, and Departments of Cell Biology and of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Douglas C Eaton
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
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Wang WW, Wang J, Zhang HJ, Wu SG, Qi GH. Transcriptome analysis reveals mechanism underlying the differential intestinal functionality of laying hens in the late phase and peak phase of production. BMC Genomics 2019; 20:970. [PMID: 31830910 PMCID: PMC6907226 DOI: 10.1186/s12864-019-6320-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 11/21/2019] [Indexed: 02/07/2023] Open
Abstract
Background The compromised performance of laying hens in the late phase of production relative to the peak production was thought to be associated with the impairment of intestinal functionality, which plays essential roles in contributing to their overall health and production performance. In the present study, RNA sequencing was used to investigate differences in the expression profile of intestinal functionality-related genes and associated pathways between laying hens in the late phase and peak phase of production. Results A total of 104 upregulated genes with 190 downregulated genes were identified in the ileum (the distal small intestine) of laying hens in the late phase of production compared to those at peak production. These upregulated genes were found to be enriched in little KEGG pathway, however, the downregulated genes were enriched in the pathways of PPAR signaling pathway, oxidative phosphorylation and glutathione metabolism. Besides, these downregulated genes were mapped to several GO clusters in relation to lipid metabolism, electron transport of respiratory chain, and oxidation resistance. Similarly, there were lower activities of total superoxide dismutase, glutathione S-transferase and Na+/K+-ATPase, and reductions of total antioxidant capacity and ATP level, along with an elevation in malondialdehyde content in the ileum of laying hens in the late phase of production as compared with those at peak production. Conclusions The intestine of laying hens in the late phase of production were predominantly characterized by a disorder of lipid metabolism, concurrent with impairments of energy production and antioxidant property. This study uncovers the mechanism underlying differences between the intestinal functionality of laying hens in the late phase and peak phase of production, thereby providing potential targets for the genetic control or dietary modulation of intestinal hypofunction of laying hens in the late phase of production.
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Affiliation(s)
- Wei-Wei Wang
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture & Rural Affairs, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Jing Wang
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture & Rural Affairs, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Hai-Jun Zhang
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture & Rural Affairs, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Shu-Geng Wu
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture & Rural Affairs, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Guang-Hai Qi
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture & Rural Affairs, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
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Zhao R, Ali G, Chang J, Komatsu S, Tsukasaki Y, Nie HG, Chang Y, Zhang M, Liu Y, Jain K, Jung BG, Samten B, Jiang D, Liang J, Ikebe M, Matthay MA, Ji HL. Proliferative regulation of alveolar epithelial type 2 progenitor cells by human Scnn1d gene. Am J Cancer Res 2019; 9:8155-8170. [PMID: 31754387 PMCID: PMC6857051 DOI: 10.7150/thno.37023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 09/16/2019] [Indexed: 01/03/2023] Open
Abstract
Lung epithelial sodium channel (ENaC) encoded by Scnn1 genes is essential for maintaining transepithelial salt and fluid homeostasis in the airway and the lung. Compared to α, β, and γ subunits, the role of respiratory δ-ENaC has not been studied in vivo due to the lack of animal models. Methods: We characterized full-length human δ802-ENaC expressed in both Xenopus oocytes and humanized transgenic mice. AT2 proliferation and differentiation in 3D organoids were analysed with FACS and a confocal microscope. Both two-electrode voltage clamp and Ussing chamber systems were applied to digitize δ802-ENaC channel activity. Immunoblotting was utilized to analyse δ802-ENaC protein. Transcripts of individual ENaC subunits in human lung tissues were quantitated with qPCR. Results: The results indicate that δ802-ENaC functions as an amiloride-inhibitable Na+ channel. Inhibitory peptide α-13 distinguishes δ802- from α-type ENaC channels. Modified proteolysis of γ-ENaC by plasmin and aprotinin did not alter the inhibition of amiloride and α-13 peptide. Expression of δ802-ENaC at the apical membrane of respiratory epithelium was detected with biophysical features similar to those of heterologously expressed channels in oocytes. δ802-ENaC regulated alveologenesis through facilitating the proliferation of alveolar type 2 epithelial cells. Conclusion: The humanized mouse line conditionally expressing human δ802-ENaC is a novel model for studying the expression and function of this protein in vivo .
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Kuan SP, Liao YSJ, Davis KM, Messer JG, Zubcevic J, Aguirre JI, Reznikov LR. Attenuated Amiloride-Sensitive Current and Augmented Calcium-Activated Chloride Current in Marsh Rice Rat (Oryzomys palustris) Airways. iScience 2019; 19:737-748. [PMID: 31491720 PMCID: PMC6731178 DOI: 10.1016/j.isci.2019.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/22/2019] [Accepted: 08/05/2019] [Indexed: 11/29/2022] Open
Abstract
Prolonged heat and sea salt aerosols pose a challenge for the mammalian airway, placing the protective airway surface liquid (ASL) at risk for desiccation. Thus, mammals inhabiting salt marshes might have acquired adaptations for ASL regulation. We studied the airways of the rice rat, a rodent that inhabits salt marshes. We discovered negligible Na+ transport through the epithelial sodium channel (ENaC). In contrast, carbachol induced a large Cl- secretory current that was blocked by the calcium-activated chloride channel (CaCC) inhibitor CaCCinhi-A01. Decreased mRNA expression of α, β, and γ ENaC, and increased mRNA expression of the CaCC transmembrane member 16A, distinguished the rice rat airway. Rice rat airway cultures also secreted fluid in response to carbachol and displayed an exaggerated expansion of the ASL volume when challenged with 3.5% NaCl. These data suggest that the rice rat airway might possess unique ion transport adaptations to facilitate survival in the salt marsh environment.
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Affiliation(s)
- Shin-Ping Kuan
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - Yan-Shin J Liao
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - Katelyn M Davis
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - Jonathan G Messer
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - Jasenka Zubcevic
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - J Ignacio Aguirre
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA
| | - Leah R Reznikov
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA.
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64
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Xu W, Zhou J, You M, Lu C, Yang W, Gong Y, Dong X. Pre-B-cell colony enhancing factor regulates the alveolar epithelial sodium-water transport system through the ERK and AKT pathways. Am J Transl Res 2019; 11:5824-5835. [PMID: 31632551 PMCID: PMC6789215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
The sodium-water transport system is crucial for alveolar fluid clearance. The pulmonary edema caused by extracorporeal circulation is mainly due to increased alveolar capillary permeability and reduced fluid clearance. We previously demonstrated that pre-B-cell colony enhancing factor (PBEF) increases alveolar capillary permeability and inhibits the sodium-water transport system. However, the specific mechanism by which PBEF inhibits the sodium-water transport system is unclear. In this study, we used HPAEpiC (alveolar type II epithelial cells) to construct an anoxia-reoxygenation model and simulate the extracorporeal circulation microenvironment. The impact of PBEF on the expression of genes and proteins implicated in sodium transport and its effect on the activation status of the ERK, P38, and AKT signaling pathways were explored in HPAEpiC by real-time fluorescent PCR and western blotting. Specific inhibitors were employed to verify the role of the three signaling pathways in the regulation of the sodium-water transport system. PBEF was substantially non-toxic to alveolar epithelial cells, inhibited the expression of ENaC, NKA, and AQP1, and affected the ERK, P38, and AKT signaling pathways. ERK pathway inhibitors attenuated PBEF-induced downregulation of EnaC, NKA, and AQP1, and increased NKA activity. P38 pathway inhibitors only attenuated PBEF-induced suppression of NKA expression. AKT pathway inhibitors potentiated the inhibitory effects of PBEF, reducing EnaC, AQP1, and NKA expression, as well as NKA activity. In conclusion, PBEF inhibited the sodium-water transport system by activation of ERK and suppression of AKT signaling.
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Affiliation(s)
- Weichang Xu
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
| | - Jianliang Zhou
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
| | - Miaomiao You
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
| | - Chao Lu
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
| | - Wei Yang
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
| | - Yi Gong
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
| | - Xiao Dong
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University Nanchang 330006, Jiangxi, China
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Looi K, Evans DJ, Garratt LW, Ang S, Hillas JK, Kicic A, Simpson SJ. Preterm birth: Born too soon for the developing airway epithelium? Paediatr Respir Rev 2019; 31:82-88. [PMID: 31103368 DOI: 10.1016/j.prrv.2018.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/31/2018] [Accepted: 11/23/2018] [Indexed: 12/17/2022]
Abstract
Birth prior to term interrupts the normal development of the respiratory system and consequently results in poor respiratory outcomes that persist throughout childhood. The mechanisms underpinning these poor respiratory outcomes are not well understood, but intrinsic abnormalities within the airway epithelium may be a contributing factor. Current evidence suggests that the airway epithelium is both structurally and functionally abnormal after preterm birth, with reports of epithelial thickening and goblet cell hyperplasia in addition to increased inflammation and apoptosis in the neonatal intensive care unit. However, studies focusing on the airway epithelium are limited and many questions remain unanswered; including whether abnormalities are a direct result of interrupted development, a consequence of exposure to inflammatory stimuli in the perinatal period or a combination of the two. In addition, the difficulty of accessing airway tissue has resulted in the majority of evidence being collected in the pre-surfactant era which may not reflect contemporary preterm birth. This review examines the consequences of preterm birth on the airway epithelium and explores the clinical relevance of currently available models whilst highlighting the need to develop a clinically relevant in vitro model to help further our understanding of the airway epithelium in preterm birth.
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Affiliation(s)
- Kevin Looi
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia
| | - Denby J Evans
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia
| | - Luke W Garratt
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia
| | - Sherlynn Ang
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia
| | - Jessica K Hillas
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia
| | - Anthony Kicic
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia; Occupation and Environment, School of Public Health, Curtin University, Bentley 6845, Western Australia, Australia; Centre for Cell Therapy and Regenerative Medicine, University of Western Australia, Nedlands 6009, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, WA 6009, Australia; UWA Centre for Child Health Research & School of Biomedical Sciences, Nedlands 6009, Western Australia, Australia
| | - Shannon J Simpson
- Telethon Kids Institute, Nedlands 6009, Western Australia, Australia.
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66
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Niu F, Xu X, Zhang R, Sun L, Gan N, Wang A. Ursodeoxycholic acid stimulates alveolar fluid clearance in LPS-induced pulmonary edema via ALX/cAMP/PI3K pathway. J Cell Physiol 2019; 234:20057-20065. [PMID: 30972764 DOI: 10.1002/jcp.28602] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/27/2019] [Accepted: 03/06/2019] [Indexed: 12/18/2022]
Abstract
This study aims to examine the impact of ursodeoxycholic acid (UDCA) on pulmonary edema and explore the underlying molecular mechanisms. The effects of UDCA on pulmonary edema were assessed through hematoxylin and eosin (H&E) staining, lung dry/wet (W/D) ratio, TNF-α/IL-1β levels of bronchoalveolar lavage fluid (BALF), protein expression of epithelial sodium channel (ENaC), and Na+ /K+ -ATPase. Besides, the detailed mechanisms were explored in primary rat alveolar type (AT) II epithelial cells by determining the effects of BOC-2 (ALX [lipoxin A4 receptor] inhibitor), Rp-cAMP (cAMP inhibitor), LY294002 (PI3K inhibitor), and H89 (PKA inhibitor) on the therapeutic effects of UDCA against lipopolysaccharide (LPS)-induced changes. Histological examination suggested that LPS-induced lung injury was obviously attenuated by UDCA. BALF TNF-α/IL-1β levels and lung W/D ratios were decreased by UDCA in LPS model rats. UDCA stimulated alveolar fluid clearance (AFC) though the upregulation of ENaC and Na+ /K+ -ATPase. BOC-2, Rp-cAMP, and LY294002 largely suppressed the therapeutic effects of UDCA. Significant attenuation of pulmonary edema and lung inflammation was revealed in LPS-challenged rats after the UDCA treatment. The therapeutic efficacy of UDCA against LPS was mainly achieved through the ALX/cAMP/PI3K pathway. Our results suggested that UDCA might be a potential drug for the treatment of pulmonary edema induced by LPS.
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Affiliation(s)
- Fangfang Niu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Xiaotao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Rong Zhang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Lingling Sun
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Ning Gan
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Aizhong Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
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Musante I, Scudieri P, Venturini A, Guidone D, Caci E, Castellani S, Conese M, Galietta LJV. Peripheral localization of the epithelial sodium channel in the apical membrane of bronchial epithelial cells. Exp Physiol 2019; 104:866-875. [PMID: 30924990 DOI: 10.1113/ep087590] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/15/2019] [Indexed: 12/14/2022]
Abstract
NEW FINDINGS What is the central question of this study? What is the precise subcellular localization of the epithelial sodium channel (ENaC) in human airway epithelium? What is the main finding and its importance? ENaC protein has an unexpected localization in the peripheral region of the apical membrane of bronchial epithelial cells, very close to tight junctions. This may be important for the mechanism of Na+ absorption ABSTRACT: The epithelial sodium channel (ENaC) has a key role in absorbing fluid across the human airway epithelium. Altered activity of ENaC may perturb the process of mucociliary clearance, thus impairing the innate defence mechanisms against microbial agents. The proteins forming ENaC are present on the apical membrane of the epithelium. However, their precise localization is unknown. In the present study, we used two antibodies recognizing the α and β ENaC subunits. Both antibodies revealed a restricted localization of ENaC in the peripheral region of the apical membrane of cultured bronchial epithelial cells, close to but not overlapping with tight junctions. In contrast, the cystic fibrosis transmembrane conductance regulator chloride channel was more diffusely expressed on the whole apical membrane. Modulation of ENaC activity by aprotinin or elastase resulted in a decrease or increase in the peripheral localization, respectively. Our results suggest that sodium absorption is mainly occurring close to tight junctions where this cation may be rapidly expelled by the Na+ /K+ pump present in lateral membranes. This arrangement of channels and pumps may limit Na+ build-up in other regions of the cells.
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Affiliation(s)
- Ilaria Musante
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Paolo Scudieri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Arianna Venturini
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Daniela Guidone
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Emanuela Caci
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Stefano Castellani
- Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
| | - Massimo Conese
- Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
| | - Luis J V Galietta
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Translational Medical Sciences (DISMET), Federico II University of Naples, Naples, Italy
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68
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Englert JA, Bobba C, Baron RM. Integrating molecular pathogenesis and clinical translation in sepsis-induced acute respiratory distress syndrome. JCI Insight 2019; 4:e124061. [PMID: 30674720 PMCID: PMC6413834 DOI: 10.1172/jci.insight.124061] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sepsis-induced acute respiratory distress syndrome (ARDS) has high morbidity and mortality and arises after lung infection or infection at extrapulmonary sites. An aberrant host response to infection leads to disruption of the pulmonary alveolar-capillary barrier, resulting in lung injury characterized by hypoxemia, inflammation, and noncardiogenic pulmonary edema. Despite increased understanding of the molecular biology underlying sepsis-induced ARDS, there are no targeted pharmacologic therapies for this devastating condition. Here, we review the molecular underpinnings of sepsis-induced ARDS with a focus on relevant clinical and translational studies that point toward novel therapeutic strategies.
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Affiliation(s)
- Joshua A. Englert
- Division of Pulmonary, Critical Care and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Christopher Bobba
- Division of Pulmonary, Critical Care and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Rebecca M. Baron
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA
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69
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Deng W, Li CY, Tong J, He J, Zhao Y, Wang DX. Insulin ameliorates pulmonary edema through the upregulation of epithelial sodium channel via the PI3K/SGK1 pathway in mice with lipopolysaccharide‑induced lung injury. Mol Med Rep 2019; 19:1665-1677. [PMID: 30628684 PMCID: PMC6390057 DOI: 10.3892/mmr.2019.9809] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 11/21/2018] [Indexed: 12/24/2022] Open
Abstract
Epithelial sodium channel (ENaC) provides the driving force for the removal of edema from the alveolar spaces in acute lung injury (ALI). Our previous study reported that insulin increased the expression of α‑ENaC, possibly via the serum/glucocorticoid‑inducible kinase‑1 (SGK1) pathway in ALI; however, the upstream regulator of SGK1 activity remains unclear. In the current study, C3H/HeN mice were subjected to lipopolysaccharide (LPS)‑induced lung injury without hyperglycemia. Exogenous insulin was administered intravenously using a micro‑osmotic pump, and intratracheal delivery of SGK1 small interfering RNA (siRNA) was performed. Furthermore, alveolar epithelial type II cells transfected with phosphatidylinositol 3‑kinase (PI3K) siRNA or SGK1 siRNA were incubated with insulin. Insulin protected the pulmonary epithelial barrier, reduced the apoptosis of alveolar epithelial cells, attenuated pulmonary edema, improved alveolar fluid clearance, and increased the expression levels of α‑, β‑ and γ‑ENaC in mice. In addition, in alveolar epithelial cells, insulin increased the expression levels of α‑, β‑ and γ‑ENaC, as well as the level of phosphorylated SGK1, which were then inhibited by the selective targeting of PI3K or SGK1 by siRNA. Taken together, the results of the present study demonstrated that insulin protected the lung epithelium and attenuated pulmonary edema through the upregulation of ENaC via the PI3K/SGK1 pathway in LPS‑induced lung injury.
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Affiliation(s)
- Wang Deng
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Chang-Yi Li
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Jin Tong
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Jing He
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Yan Zhao
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Dao-Xin Wang
- Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
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70
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Brand JD, Lazrak A, Trombley JE, Shei RJ, Adewale AT, Tipper JL, Yu Z, Ashtekar AR, Rowe SM, Matalon S, Harrod KS. Influenza-mediated reduction of lung epithelial ion channel activity leads to dysregulated pulmonary fluid homeostasis. JCI Insight 2018; 3:123467. [PMID: 30333319 DOI: 10.1172/jci.insight.123467] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/06/2018] [Indexed: 02/06/2023] Open
Abstract
Severe influenza (IAV) infection can develop into bronchopneumonia and edema, leading to acquired respiratory distress syndrome (ARDS) and pathophysiology. Underlying causes for pulmonary edema and aberrant fluid regulation largely remain unknown, particularly regarding the role of viral-mediated mechanisms. Herein, we show that distinct IAV strains reduced the functions of the epithelial sodium channel (ENaC) and the cystic fibrosis transmembrane regulator (CFTR) in murine respiratory and alveolar epithelia in vivo, as assessed by measurements of nasal potential differences and single-cell electrophysiology. Reduced ion channel activity was distinctly limited to virally infected cells in vivo and not bystander uninfected lung epithelium. Multiple lines of evidence indicated ENaC and CFTR dysfunction during the acute infection period; however, only CFTR dysfunction persisted beyond the infection period. ENaC, CFTR, and Na,K-ATPase activities and protein levels were also reduced in virally infected human airway epithelial cells. Reduced ENaC and CFTR led to changes in airway surface liquid morphology of human tracheobronchial cultures and airways of IAV-infected mice. Pharmacologic correction of CFTR function ameliorated IAV-induced physiologic changes. These changes are consistent with mucous stasis and pulmonary edema; furthermore, they indicate that repurposing therapeutic interventions correcting CFTR dysfunction may be efficacious for treatment of IAV lung pathophysiology.
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Affiliation(s)
- Jeffrey D Brand
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - Ahmed Lazrak
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - John E Trombley
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - Ren-Jay Shei
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care, and.,Gregory Fleming James Cystic Fibrosis Research Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - A Timothy Adewale
- Gregory Fleming James Cystic Fibrosis Research Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jennifer L Tipper
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - Zhihong Yu
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - Amit R Ashtekar
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - Steven M Rowe
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care, and.,Gregory Fleming James Cystic Fibrosis Research Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
| | - Kevin S Harrod
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular and Translational Biomedicine
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71
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Webster MJ, Reidel B, Tan CD, Ghosh A, Alexis NE, Donaldson SH, Kesimer M, Ribeiro CMP, Tarran R. SPLUNC1 degradation by the cystic fibrosis mucosal environment drives airway surface liquid dehydration. Eur Respir J 2018; 52:13993003.00668-2018. [PMID: 30190268 DOI: 10.1183/13993003.00668-2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 08/06/2018] [Indexed: 02/07/2023]
Abstract
The multi-organ disease cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR) that lead to diminished transepithelial anion transport. CF lungs are characterised by airway surface liquid (ASL) dehydration, chronic infection/inflammation and neutrophilia. Dysfunctional CFTR may upregulate the epithelial Na+ channel (ENaC), further exacerbating dehydration. We previously demonstrated that short palate lung and nasal epithelial clone 1 (SPLUNC1) negatively regulates ENaC in normal airway epithelia.Here, we used pulmonary tissue samples, sputum and human bronchial epithelial cells (HBECs) to determine whether SPLUNC1 could regulate ENaC in a CF-like environment.We found reduced endogenous SPLUNC1 in CF secretions, and rapid degradation of recombinant SPLUNC1 (rSPLUNC1) by CF secretions. Normal sputum, containing SPLUNC1 and SPLUNC1-derived peptides, inhibited ENaC in both normal and CF HBECs. Conversely, CF sputum activated ENaC, and rSPLUNC1 could not reverse this phenomenon. Additionally, we observed upregulation of ENaC protein levels in human CF bronchi. Unlike SPLUNC1, the novel SPLUNC1-derived peptide SPX-101 resisted protease degradation, bound apically to HBECs, inhibited ENaC and prevented ASL dehydration following extended pre-incubation with CF sputum.Our data indicate that CF mucosal secretions drive ASL hyperabsorption and that protease-resistant peptides, e.g. SPX-101, can reverse this effect to rehydrate CF ASL.
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Affiliation(s)
- Megan J Webster
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA
| | - Boris Reidel
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA
| | - Chong D Tan
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA
| | - Arunava Ghosh
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA
| | - Neil E Alexis
- Center for Asthma and Lung Biology, The University of North Carolina, Chapel Hill, NC, USA
| | - Scott H Donaldson
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA.,Division of Pulmonary and Critical Care Medicine, The University of North Carolina, Chapel Hill, NC, USA
| | - Mehmet Kesimer
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA
| | - Carla M P Ribeiro
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA.,Dept of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC, USA
| | - Robert Tarran
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, NC, USA .,Dept of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC, USA
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72
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Webster MJ, Tarran R. Slippery When Wet: Airway Surface Liquid Homeostasis and Mucus Hydration. CURRENT TOPICS IN MEMBRANES 2018; 81:293-335. [PMID: 30243435 DOI: 10.1016/bs.ctm.2018.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The ability to regulate cell volume is crucial for normal physiology; equally the regulation of extracellular fluid homeostasis is of great importance. Alteration of normal extracellular fluid homeostasis contributes to the development of several diseases including cystic fibrosis. With regard to the airway surface liquid (ASL), which lies apically on top of airway epithelia, ion content, pH, mucin and protein abundance must be tightly regulated. Furthermore, airway epithelia must be able to switch from an absorptive to a secretory state as required. A heterogeneous population of airway epithelial cells regulate ASL solute and solvent composition, and directly secrete large mucin molecules, antimicrobials, proteases and soluble mediators into the airway lumen. This review focuses on how epithelial ion transport influences ASL hydration and ASL pH, with a specific focus on the roles of anion and cation channels and exchangers. The role of ions and pH in mucin expansion is also addressed. With regard to fluid volume regulation, we discuss the roles of nucleotides, adenosine and the short palate lung and nasal epithelial clone 1 (SPLUNC1) as soluble ASL mediators. Together, these mechanisms directly influence ciliary beating and in turn mucociliary clearance to maintain sterility and to detoxify the airways. Whilst all of these components are regulated in normal airways, defective ion transport and/or mucin secretion proves detrimental to lung homeostasis as such we address how defective ion and fluid transport, and a loss of homeostatic mechanisms, contributes to the development of pathophysiologies associated with cystic fibrosis.
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Affiliation(s)
- Megan J Webster
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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73
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Richard C, Shabbir W, Ferraro P, Massé C, Berthiaume Y. Alveolar liquid clearance in lung injury: Evaluation of the impairment of the β 2-adrenergic agonist response in an ischemia-reperfusion lung injury model. Respir Physiol Neurobiol 2018; 259:104-110. [PMID: 30171906 DOI: 10.1016/j.resp.2018.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 07/27/2018] [Accepted: 08/27/2018] [Indexed: 01/05/2023]
Abstract
While alveolar liquid clearance (ALC) mediated by the β2-adrenergic receptor (β2-AR) plays an important role in lung edema resolution in certain models of lung injury, in more severe lung injury models, this response might disappear. Indeed, we have shown that in an ischemia-reperfusion-induced lung injury model, β2-agonists do not enhance ALC. The objective of this study was to determine if downregulation of the β2-AR could explain the lack of response to β2-agonists in this lung injury model. In an in vivo canine model of lung transplantation, we observed no change in β2-AR concentration or affinity in the injured transplanted lungs compared to the native lungs. Furthermore, we could not enhance ALC in transplanted lungs with dcAMP + aminophylline, a treatment that bypasses the β2-adrenergic receptor and is known to stimulate ALC in normal lungs. However, transplantation decreased αENaC expression in the lungs by 50%. We conclude that the lack of response to β2-agonists in ischemia-reperfusion-induced lung injury is not associated with significant downregulation of the β2-adrenergic receptors but is attributable to decreased expression of the ENaC channel, which is essential for sodium transport and alveolar liquid clearance in the lung.
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Affiliation(s)
- Chloé Richard
- Centre de recherche, Centre hospitalier de l'université de Montréal (CHUM), Canada
| | - Waheed Shabbir
- Institute of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Pasquale Ferraro
- Centre de recherche, Centre hospitalier de l'université de Montréal (CHUM), Canada; Département de chirurgie, Université de Montréal, Montréal, Québec, Canada
| | - Chantal Massé
- Centre de recherche, Centre hospitalier de l'université de Montréal (CHUM), Canada; Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
| | - Yves Berthiaume
- Centre de recherche, Centre hospitalier de l'université de Montréal (CHUM), Canada; Département de médecine, Université de Montréal, Montréal, Québec, Canada; Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada.
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74
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Dagenais A, Desjardins J, Shabbir W, Roy A, Filion D, Sauvé R, Berthiaume Y. Loss of barrier integrity in alveolar epithelial cells downregulates ENaC expression and activity via Ca 2+ and TRPV4 activation. Pflugers Arch 2018; 470:1615-1631. [PMID: 30088081 DOI: 10.1007/s00424-018-2182-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 06/14/2018] [Accepted: 07/09/2018] [Indexed: 01/08/2023]
Abstract
The epithelial Na channel (ENaC) plays an essential role in lung physiology by modulating the amount of liquid lining the respiratory epithelium. Here, we tested the effect of breaking alveolar epithelial cell barrier integrity on ENaC expression and function. We found that either mechanical wounding by scratching the monolayer or disruption of tight junction with EDTA induced a ~ 50% decrease of α,β and γENaC mRNA expression and an 80% reduction of ENaC short-circuit current (Isc) at 6 h. Scratching the cell monolayer generated a Ca2+ wave that spread from the margin of the scratch to distant cells. Pretreatment with BAPTA-AM, an intracellular Ca2+ chelator, abolished the effect of mechanical wounding and EDTA on αENaC mRNA expression, suggesting that [Ca2+]i is important for this modulation. We tested the hypothesis that a mechanosensitive channel such as TRPV4, a cationic channel known to increase [Ca2+]i, could mediate this effect. Activation of the channel with the TRPV4 specific agonist GSK-1016790A (GSK) decreased αENAC mRNA expression and almost completely abolished ENaC Isc. Pretreatment of alveolar epithelial cells with HC-067047 (HC0), a specific TRPV4 antagonist, reduced the extent of αENAC mRNA downregulation by mechanical wounding and EDTA. Altogether, our results suggest that mechanical stress induced by wounding or TRPV4-mediated loss of tight junction increases [Ca2+]i and elicits a Ca2+ wave that affects ENaC expression and function away from the site of injury. These data are important to better understand how Ca2+ signaling affects lung liquid clearance in injured lungs.
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Affiliation(s)
- André Dagenais
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montreal, Quebec, H2W 1R7, Canada.
- Département de médecine, Université de Montréal, Montreal, Quebec, Canada.
| | - Julie Desjardins
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montreal, Quebec, H2W 1R7, Canada
| | - Waheed Shabbir
- Institute of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Antoine Roy
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montreal, Quebec, H2W 1R7, Canada
| | - Dominic Filion
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montreal, Quebec, H2W 1R7, Canada
| | - Rémy Sauvé
- Département de pharmacologie et physiologie, Université de Montréal, Montreal, Quebec, Canada
| | - Yves Berthiaume
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montreal, Quebec, H2W 1R7, Canada
- Département de médecine, Université de Montréal, Montreal, Quebec, Canada
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75
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Insulin-Like Growth Factor-1 Signaling in Lung Development and Inflammatory Lung Diseases. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6057589. [PMID: 30018981 PMCID: PMC6029485 DOI: 10.1155/2018/6057589] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/06/2018] [Indexed: 12/19/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) was firstly identified as a hormone that mediates the biological effects of growth hormone. Accumulating data have indicated the role of IGF-1 signaling pathway in lung development and diseases such as congenital disorders, cancers, inflammation, and fibrosis. IGF-1 signaling modulates the development and differentiation of many types of lung cells, including airway basal cells, club cells, alveolar epithelial cells, and fibroblasts. IGF-1 signaling deficiency results in alveolar hyperplasia in humans and disrupted lung architecture in animal models. The components of IGF-1 signaling pathways are potentiated as biomarkers as they are dysregulated locally or systemically in lung diseases, whereas data may be inconsistent or even paradoxical among different studies. The usage of IGF-1-based therapeutic agents urges for more researches in developmental disorders and inflammatory lung diseases, as the majority of current data are collected from limited number of animal experiments and are generally less exuberant than those in lung cancer. Elucidation of these questions by further bench-to-bedside researches may provide us with rational clinical diagnostic approaches and agents concerning IGF-1 signaling in lung diseases.
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76
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Moore PJ, Reidel B, Ghosh A, Sesma J, Kesimer M, Tarran R. Cigarette smoke modifies and inactivates SPLUNC1, leading to airway dehydration. FASEB J 2018; 32:fj201800345R. [PMID: 29890087 PMCID: PMC6219833 DOI: 10.1096/fj.201800345r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/21/2018] [Indexed: 01/14/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) is a growing cause of morbidity and mortality worldwide. Cigarette smoke (CS) exposure, a major cause of COPD, dysregulates airway epithelial ion transport and diminishes airway surface liquid (ASL) volume. Short palate lung and nasal epithelial clone 1 (SPLUNC1) is secreted into the airway lumen where it maintains airway hydration via interactions with the epithelial Na+ channel (ENaC). Although ASL hydration is dysregulated in CS-exposed/COPD airways, effects of CS on SPLUNC1 have not been elucidated. We hypothesized that CS alters SPLUNC1 activity, therefore contributing to ASL dehydration. CS exposure caused irreversible SPLUNC1 aggregation and prevented SPLUNC1 from internalizing ENaC and maintaining ASL hydration. Proteomic analysis revealed αβ-unsaturated aldehyde modifications to SPLUNC1's cysteine residues. Removal of these cysteines prevented SPLUNC1 from regulating ENaC/ASL volume. In contrast, SPX-101, a peptide mimetic of natural SPLUNC1, that internalizes ENaC, but does not contain cysteines was unaffected by CS. SPX-101 increased ASL hydration and attenuated ENaC activity in airway cultures after CS exposure and prolonged survival in a chronic airway disease model. These findings suggest that the CS-induced defects in SPLUNC1 can be circumvented, thus making SPX-101 a novel candidate for the treatment of mucus dehydration in COPD. -Moore, P. J., Reidel, B., Ghosh, A., Sesma, J., Kesimer, M., Tarran, R. Cigarette smoke modifies and inactivates SPLUNC1, leading to airway dehydration.
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Affiliation(s)
- Patrick J. Moore
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Boris Reidel
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Arunava Ghosh
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina, USA
| | | | - Mehmet Kesimer
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, North Carolina, USA
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77
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Kim CS, Ahmad S, Wu T, Walton WG, Redinbo MR, Tarran R. SPLUNC1 is an allosteric modulator of the epithelial sodium channel. FASEB J 2018; 32:2478-2491. [PMID: 29295861 PMCID: PMC5901381 DOI: 10.1096/fj.201701126r] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/04/2017] [Indexed: 01/20/2023]
Abstract
Cystic fibrosis (CF) is a common genetic disease with significantly increased mortality. CF airways exhibit ion transport abnormalities, including hyperactivity of the epithelial Na+ channel (ENaC). Short-palate lung and nasal epithelial clone 1 (SPLUNC1) is a multifunctional innate defense protein that is secreted into the airway lumen. We have previously demonstrated that SPLUNC1 binds to and inhibits ENaC to maintain fluid homeostasis in airway epithelia and that this process fails in CF airways. Despite this, how SPLUNC1 actually regulates ENaC is unknown. Here, we found that SPLUNC1 caused αγ-ENaC to internalize, whereas SPLUNC1 and β-ENaC remained at the plasma membrane. Additional studies revealed that SPLUNC1 increased neural precursor cell-expressed developmentally down-regulated protein 4-2-dependent ubiquitination of α- but not β- or γ-ENaC. We also labeled intracellular ENaC termini with green fluorescent protein and mCherry, and found that extracellular SPLUNC1 altered intracellular ENaC Forster resonance energy transfer. Taken together, our data indicate that SPLUNC1 is an allosteric regulator of ENaC that dissociates αβγ-ENaC to generate a new SPLUNC1-β-ENaC complex. These data indicate a novel mode for regulating ENaC at the plasma membrane.-Kim, C. S., Ahmad, S., Wu, T., Walton, W. G., Redinbo, M. R., Tarran, R. SPLUNC1 is an allosteric modulator of the epithelial sodium channel.
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Affiliation(s)
- Christine Seulki Kim
- Cystic Fibrosis Center, Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Saira Ahmad
- Cystic Fibrosis Center, Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Tongde Wu
- Cystic Fibrosis Center, Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - William G. Walton
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Matthew R. Redinbo
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Robert Tarran
- Cystic Fibrosis Center, Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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78
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Hakansson AP, Orihuela CJ, Bogaert D. Bacterial-Host Interactions: Physiology and Pathophysiology of Respiratory Infection. Physiol Rev 2018; 98:781-811. [PMID: 29488821 PMCID: PMC5966719 DOI: 10.1152/physrev.00040.2016] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 09/08/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023] Open
Abstract
It has long been thought that respiratory infections are the direct result of acquisition of pathogenic viruses or bacteria, followed by their overgrowth, dissemination, and in some instances tissue invasion. In the last decades, it has become apparent that in contrast to this classical view, the majority of microorganisms associated with respiratory infections and inflammation are actually common members of the respiratory ecosystem and only in rare circumstances do they cause disease. This suggests that a complex interplay between host, environment, and properties of colonizing microorganisms together determines disease development and its severity. To understand the pathophysiological processes that underlie respiratory infectious diseases, it is therefore necessary to understand the host-bacterial interactions occurring at mucosal surfaces, along with the microbes inhabiting them, during symbiosis. Current knowledge regarding host-bacterial interactions during asymptomatic colonization will be discussed, including a plausible role for the human microbiome in maintaining a healthy state. With this as a starting point, we will discuss possible disruptive factors contributing to dysbiosis, which is likely to be a key trigger for pathobionts in the development and pathophysiology of respiratory diseases. Finally, from this renewed perspective, we will reflect on current and potential new approaches for treatment in the future.
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Affiliation(s)
- A P Hakansson
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University , Lund , Sweden ; Department of Microbiology, University of Alabama at Birmingham , Birmingham, Alabama ; and Center for Inflammation Research, Queens Medical Research Institute, University of Edinburgh , Edinburgh , United Kingdom
| | - C J Orihuela
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University , Lund , Sweden ; Department of Microbiology, University of Alabama at Birmingham , Birmingham, Alabama ; and Center for Inflammation Research, Queens Medical Research Institute, University of Edinburgh , Edinburgh , United Kingdom
| | - D Bogaert
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University , Lund , Sweden ; Department of Microbiology, University of Alabama at Birmingham , Birmingham, Alabama ; and Center for Inflammation Research, Queens Medical Research Institute, University of Edinburgh , Edinburgh , United Kingdom
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79
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Intermittent Hypoxia Increases the Severity of Bleomycin-Induced Lung Injury in Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:1240192. [PMID: 29725493 PMCID: PMC5872634 DOI: 10.1155/2018/1240192] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/03/2018] [Accepted: 01/10/2018] [Indexed: 01/02/2023]
Abstract
Background Severe obstructive sleep apnea (OSA) with chronic intermittent hypoxia (IH) is common in idiopathic pulmonary fibrosis (IPF). Here, we evaluated the impact of IH on bleomycin- (BLM-) induced pulmonary fibrosis in mice. Methods C57BL/6J mice received intratracheal BLM or saline and were exposed to IH (40 cycles/hour; FiO2 nadir: 6%; 8 hours/day) or intermittent air (IA). In the four experimental groups, we evaluated (i) survival; (ii) alveolar inflammation, pulmonary edema, lung oxidative stress, and antioxidant enzymes; (iii) lung cell apoptosis; and (iv) pulmonary fibrosis. Results Survival at day 21 was lower in the BLM-IH group (p < 0.05). Pulmonary fibrosis was more severe at day 21 in BLM-IH mice, as assessed by lung collagen content (p = 0.02) and histology. At day 4, BLM-IH mice developed a more severe neutrophilic alveolitis, (p < 0.001). Lung oxidative stress was observed, and superoxide dismutase and glutathione peroxidase expression was decreased in BLM-IH mice (p < 0.05 versus BLM-IA group). At day 8, pulmonary edema was observed and lung cell apoptosis was increased in the BLM-IH group. Conclusion These results show that exposure to chronic IH increases mortality, lung inflammation, and lung fibrosis in BLM-treated mice. This study raises the question of the worsening impact of severe OSA in IPF patients.
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80
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Yang G, Pillich H, White R, Czikora I, Pochic I, Yue Q, Hudel M, Gorshkov B, Verin A, Sridhar S, Isales CM, Eaton DC, Hamacher J, Chakraborty T, Lucas R. Listeriolysin O Causes ENaC Dysfunction in Human Airway Epithelial Cells. Toxins (Basel) 2018; 10:toxins10020079. [PMID: 29439494 PMCID: PMC5848180 DOI: 10.3390/toxins10020079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/01/2018] [Accepted: 02/07/2018] [Indexed: 01/22/2023] Open
Abstract
Pulmonary permeability edema is characterized by reduced alveolar Na⁺ uptake capacity and capillary barrier dysfunction and is a potentially lethal complication of listeriosis. Apical Na⁺ uptake is mainly mediated by the epithelial sodium channel (ENaC) and initiates alveolar liquid clearance. Here we examine how listeriolysin O (LLO), the pore-forming toxin of Listeria monocytogenes, impairs the expression and activity of ENaC. To that purpose, we studied how sub-lytic concentrations of LLO affect negative and positive regulators of ENaC expression in the H441 airway epithelial cell line. LLO reduced expression of the crucial ENaC-α subunit in H441 cells within 2 h and this was preceded by activation of PKC-α, a negative regulator of the channel's expression. At later time points, LLO caused a significant reduction in the phosphorylation of Sgk-1 at residue T256 and of Akt-1 at residue S473, both of which are required for full activation of ENaC. The TNF-derived TIP peptide prevented LLO-mediated PKC-α activation and restored phospho-Sgk-1-T256. The TIP peptide also counteracted the observed LLO-induced decrease in amiloride-sensitive Na⁺ current and ENaC-α expression in H441 cells. Intratracheally instilled LLO caused profound pulmonary edema formation in mice, an effect that was prevented by the TIP peptide; thus indicating the therapeutic potential of the peptide for the treatment of pore-forming toxin-associated permeability edema.
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Affiliation(s)
- Guang Yang
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Helena Pillich
- Institute of Medical Microbiology, Justus-Liebig University Giessen, 35392 Gießen, Germany.
| | - Richard White
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
- Department of Biomedical Sciences, Georgia Campus-Philadelphia College of Osteopathic Medicine, Atlanta, GA 30224, USA.
| | - Istvan Czikora
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Isabelle Pochic
- Biochemical Pharmacology, University of Konstanz, 78464 Konstanz, Germany.
- Sandoz Inc., 83607 Holzkirchen, Germany.
| | - Qiang Yue
- Department of Physiology, Emory School of Medicine, Atlanta, GA 30307, USA.
| | - Martina Hudel
- Institute of Medical Microbiology, Justus-Liebig University Giessen, 35392 Gießen, Germany.
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Alexander Verin
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Supriya Sridhar
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Carlos M Isales
- Department of Medicine, Medical College of Georgia, Augusta, GA 30901, USA.
| | - Douglas C Eaton
- Department of Physiology, Emory School of Medicine, Atlanta, GA 30307, USA.
| | - Jürg Hamacher
- Biochemical Pharmacology, University of Konstanz, 78464 Konstanz, Germany.
- Department of Pneumology, Lindenhofspital, 3001 Bern, Switzerland.
- Internal, Pulmonary and Critical Care Medicine, Saarland University, 66424 Homburg/Saar, Germany.
- Lungen-und Atmungsstifung, 3001 Bern, Switzerland.
| | - Trinad Chakraborty
- Institute of Medical Microbiology, Justus-Liebig University Giessen, 35392 Gießen, Germany.
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
- Department of Medicine, Medical College of Georgia, Augusta, GA 30901, USA.
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81
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He M, Liu S, Gallolu Kankanamalage S, Borromeo MD, Girard L, Gazdar AF, Minna JD, Johnson JE, Cobb MH. The Epithelial Sodium Channel (αENaC) Is a Downstream Therapeutic Target of ASCL1 in Pulmonary Neuroendocrine Tumors. Transl Oncol 2018; 11:292-299. [PMID: 29413762 PMCID: PMC5884185 DOI: 10.1016/j.tranon.2018.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/03/2018] [Accepted: 01/05/2018] [Indexed: 12/16/2022] Open
Abstract
Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma, designated as a recalcitrant cancer by the National Cancer Institute, in urgent need of new rational therapeutic targets. Previous studies have determined that the basic helix-loop-helix transcription factor achaete-scute homolog 1 (ASCL1) is essential for the survival and progression of a fraction of pulmonary neuroendocrine cancer cells, which include both SCLC and a subset of non-SCLC. Previously, to understand how ASCL1 initiates tumorigenesis in pulmonary neuroendocrine cancer and identify the transcriptional targets of ASCL1, whole-genome RNA-sequencing analysis combined with chromatin immunoprecipitation-sequencing was performed with a series of lung cancer cell lines. From this analysis, we discovered that the gene SCNN1A, which encodes the alpha subunit of the epithelial sodium channel (αENaC), is highly correlated with ASCL1 expression in SCLC. The product of the SCNN1A gene ENaC can be pharmacologically inhibited with amiloride, a drug that has been used clinically for close to 50 years. Amiloride inhibited growth of ASCL1-dependent SCLC more strongly than ASCL1-independent SCLC in vitro and slowed growth of ASCL1-driven SCLC in xenografts. We conclude that SCNN1A/αENaC is a direct transcriptional target of the neuroendocrine lung cancer lineage oncogene ASCL1 that can be pharmacologically targeted with antitumor effects.
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Affiliation(s)
- Min He
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Shanshan Liu
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | | | - Mark D Borromeo
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Luc Girard
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Adi F Gazdar
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - John D Minna
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jane E Johnson
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas.
| | - Melanie H Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas.
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82
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SOCS-1 rescues IL-1β-mediated suppression of epithelial sodium channel in mouse lung epithelial cells via ASK-1. Oncotarget 2018; 7:29081-91. [PMID: 27058411 PMCID: PMC5045379 DOI: 10.18632/oncotarget.8543] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 03/16/2016] [Indexed: 01/09/2023] Open
Abstract
Background Acute lung injury (ALI) is characterized by alveolar damage, increased levels of pro-inflammatory cytokines and impaired alveolar fluid clearance. Recently, we showed that the deletion of Apoptosis signal-regulating kinase 1 (ASK1) protects against hyperoxia-induced acute lung injury (HALI) by suppressing IL-1β and TNF-α. Previously, our data revealed that the suppressor of cytokine signaling-1 (SOCS-1) overexpression restores alveolar fluid clearance in HALI by inhibiting ASK-1 and suppressing IL-1β levels. Furthermore, IL-1β is known to inhibit the expression of epithelial sodium channel α-subunit (ENaC) via a p38 MAPK signaling pathway. Objective To determine whether SOCS-1 overexpression in MLE-12 cells would protect against IL-1β-mediated depletion of αENaC by suppressing ASK-1 expression. Methods We co-transfected MLE-12 cells with SOCS-1 overexpressing plasmid with or without IL-1β in the presence or absence of sodium channel inhibitor, amiloride. We measured potential difference, transepithelial current, resistance, and sodium uptake levels across MLE-12 cells. We studied the effect of ASK-1 depletion, as well as ASK-1 and SOCS-1 overexpression on αENaC expression. Results SOCS-1 overexpression sufficiently restored transepithelial current and resistance in MLE-12 cells treated with either IL-1β or amiloride. The αENaC mRNA levels and sodium transport were increased in SOCS-1 overexpressing MLE-12 cells exposed to IL-1β. Depletion of ASK-1 in MLE-12 cells increased αENaC mRNA levels. Interestingly, SOCS-1 overexpression restored αENaC expression in MLE-12 cells in the presence of ASK-1 overexpression. Conclusion Collectively, these findings suggest that SOCS-1 may exert its protective effect by rescuing αENaC expression via suppression of ASK-1.
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83
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Hamacher J, Hadizamani Y, Borgmann M, Mohaupt M, Männel DN, Moehrlen U, Lucas R, Stammberger U. Cytokine-Ion Channel Interactions in Pulmonary Inflammation. Front Immunol 2018; 8:1644. [PMID: 29354115 PMCID: PMC5758508 DOI: 10.3389/fimmu.2017.01644] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/10/2017] [Indexed: 12/12/2022] Open
Abstract
The lungs conceptually represent a sponge that is interposed in series in the bodies’ systemic circulation to take up oxygen and eliminate carbon dioxide. As such, it matches the huge surface areas of the alveolar epithelium to the pulmonary blood capillaries. The lung’s constant exposure to the exterior necessitates a competent immune system, as evidenced by the association of clinical immunodeficiencies with pulmonary infections. From the in utero to the postnatal and adult situation, there is an inherent vital need to manage alveolar fluid reabsorption, be it postnatally, or in case of hydrostatic or permeability edema. Whereas a wealth of literature exists on the physiological basis of fluid and solute reabsorption by ion channels and water pores, only sparse knowledge is available so far on pathological situations, such as in microbial infection, acute lung injury or acute respiratory distress syndrome, and in the pulmonary reimplantation response in transplanted lungs. The aim of this review is to discuss alveolar liquid clearance in a selection of lung injury models, thereby especially focusing on cytokines and mediators that modulate ion channels. Inflammation is characterized by complex and probably time-dependent co-signaling, interactions between the involved cell types, as well as by cell demise and barrier dysfunction, which may not uniquely determine a clinical picture. This review, therefore, aims to give integrative thoughts and wants to foster the unraveling of unmet needs in future research.
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Affiliation(s)
- Jürg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Internal Medicine V - Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Yalda Hadizamani
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Michèle Borgmann
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Markus Mohaupt
- Internal Medicine, Sonnenhofspital Bern, Bern, Switzerland
| | | | - Ueli Moehrlen
- Paediatric Visceral Surgery, Universitäts-Kinderspital Zürich, Zürich, Switzerland
| | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Vascular Biology Center, Medical College of Georgia, Augusta, GA, United States
| | - Uz Stammberger
- Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Novartis Institutes for Biomedical Research, Translational Clinical Oncology, Novartis Pharma AG, Basel, Switzerland
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84
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Abstract
PURPOSE High levels of NaCl in the diet are associated with both cardiac and renal fibrosis, but whether salt intake affects pulmonary fibrosis has not been examined. AIM OF THE STUDY To test the hypothesis that salt intake might affect pulmonary fibrosis. MATERIALS AND METHODS Mice were fed low, normal, or high salt diets for 2 weeks, and then treated with oropharyngeal bleomycin to induce pulmonary fibrosis, or oropharyngeal saline as a control. RESULTS As determined by collagen staining of lung sections, and protein levels and cell numbers in the bronchoalveolar lavage (BAL) fluid at 21 days after bleomycin, the high salt diet did not exacerbate bleomycin-induced fibrosis, while the low salt diet attenuated fibrosis. For the bleomycin-treated mice, staining of the post-BAL lung sections indicated that compared to the regular salt diet, high salt increased the number of Ly6c-positive macrophages and decreased the number of CD11c and CD206-positive macrophages and dendritic cells. The low salt diet caused bleomycin-induced leukocyte numbers to be similar to control saline-treated mice, but reduced numbers of CD45/collagen-VI positive fibrocytes. In the saline controls, low dietary salt decreased CD11b and CD11c positive cells in lung sections, and high dietary salt increased fibrocytes. CONCLUSIONS Together, these data suggest the possibility that a low salt diet might attenuate pulmonary fibrosis.
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Affiliation(s)
- Wensheng Chen
- a Department of Biology , Texas A&M University , College Station , TX , USA.,b Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine , Hefei , China
| | - Darrell Pilling
- a Department of Biology , Texas A&M University , College Station , TX , USA
| | - Richard H Gomer
- a Department of Biology , Texas A&M University , College Station , TX , USA
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85
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Ding Y, Zhao R, Zhao X, Matthay MA, Nie HG, Ji HL. ENaCs as Both Effectors and Regulators of MiRNAs in Lung Epithelial Development and Regeneration. Cell Physiol Biochem 2017; 44:1120-1132. [PMID: 29179210 PMCID: PMC5884700 DOI: 10.1159/000485417] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 10/14/2017] [Indexed: 12/14/2022] Open
Abstract
Epithelial sodium channels (ENaC) play an important role in re-absorbing excessive luminal fluid by building up an osmotic Na+ gradient across the tight epithelium in the airway, the lung, the kidney, and the colon. The ENaC is a major pathway for retention of salt in kidney too. MicroRNAs (miRs), a group of non-coding RNAs that regulate gene expression at the post-transcriptional level, have emerged as a novel class of regulators for ENaC. Given the ENaC pathway is crucial for maintaining fluid homeostasis in the lung and the kidney and other cavities, we summarized the cross-talk between ENaC and miRs and recapitulated the underlying regulatory factors, including aldosterone, transforming growth factor-β1, and vascular endothelial growth factor-A in the lung and other epithelial tissues/organs. We have compared the profiling of miRs between normal and injured mice and human lungs, which showed a significant alteration in numerous miRs in mouse models of LPS and ventilator induced ARDS. In addition, we reiterated the potential regulation of the ENaC by miRs in stem/ progenitor cell-based re-epithelialization, and identified a promising pharmaceutic target of ENaC for removing edema fluid in ARDS by mesenchymal stem cells-released paracrine. In conclusion, it seems that the interactions between miRs and scnn1s/ENaCs are critical for lung development, epithelial cell turnover in adult lungs, and re-epithelialization for repair.
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Affiliation(s)
- Yan Ding
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Runzhen Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler Texas
- Texas Lung Injury Institute, University of Texas Health Northeast, Tyler Texas, USA
| | - Xiaoli Zhao
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Michael A. Matthay
- Departments of Medicine and Anesthesia, Cardiovascular Research Institute, University of California, San Francisco, California, USA
| | - Hong-Guang Nie
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Hong-Long Ji
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler Texas
- Texas Lung Injury Institute, University of Texas Health Northeast, Tyler Texas, USA
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86
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Bartoszewski R, Matalon S, Collawn JF. Ion channels of the lung and their role in disease pathogenesis. Am J Physiol Lung Cell Mol Physiol 2017; 313:L859-L872. [PMID: 29025712 PMCID: PMC5792182 DOI: 10.1152/ajplung.00285.2017] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 12/16/2022] Open
Abstract
Maintenance of normal epithelial ion and water transport in the lungs includes providing a thin layer of surface liquid that coats the conducting airways. This airway surface liquid is critical for normal lung function in a number of ways but, perhaps most importantly, is required for normal mucociliary clearance and bacterial removal. Preservation of the appropriate level of hydration, pH, and viscosity for the airway surface liquid requires the proper regulation and function of a battery of different types of ion channels and transporters. Here we discuss how alterations in ion channel/transporter function often lead to lung pathologies.
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Affiliation(s)
- Rafal Bartoszewski
- Department of Biology and Pharmaceutical Botany, Medical University of Gdansk, Gdansk, Poland
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
- Gregory Fleming James Cystic Fibrosis Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - James F Collawn
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
- Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
- Gregory Fleming James Cystic Fibrosis Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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87
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Terryah ST, Fellner RC, Ahmad S, Moore PJ, Reidel B, Sesma JI, Kim CS, Garland AL, Scott DW, Sabater JR, Carpenter J, Randell SH, Kesimer M, Abraham WM, Arendshorst WJ, Tarran R. Evaluation of a SPLUNC1-derived peptide for the treatment of cystic fibrosis lung disease. Am J Physiol Lung Cell Mol Physiol 2017; 314:L192-L205. [PMID: 28982737 DOI: 10.1152/ajplung.00546.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In cystic fibrosis (CF) lungs, epithelial Na+ channel (ENaC) hyperactivity causes a reduction in airway surface liquid volume, leading to decreased mucocilliary clearance, chronic bacterial infection, and lung damage. Inhibition of ENaC is an attractive therapeutic option. However, ENaC antagonists have failed clinically because of off-target effects in the kidney. The S18 peptide is a naturally occurring short palate lung and nasal epithelial clone 1 (SPLUNC1)-derived ENaC antagonist that restores airway surface liquid height for up to 24 h in CF human bronchial epithelial cultures. However, its efficacy and safety in vivo are unknown. To interrogate the potential clinical efficacy of S18, we assessed its safety and efficacy using human airway cultures and animal models. S18-mucus interactions were tested using superresolution microscopy, quartz crystal microbalance with dissipation, and confocal microscopy. Human and murine airway cultures were used to measure airway surface liquid height. Off-target effects were assessed in conscious mice and anesthetized rats. Morbidity and mortality were assessed in the β-ENaC-transgenic (Tg) mouse model. Restoration of normal mucus clearance was measured in cystic fibrosis transmembrane conductance regulator inhibitor 172 [CFTR(inh)-172]-challenged sheep. We found that S18 does not interact with mucus and rapidly penetrated dehydrated CF mucus. Compared with amiloride, an early generation ENaC antagonist, S18 displayed a superior ability to slow airway surface liquid absorption, reverse CFTR(inh)-172-induced reduction of mucus transport, and reduce morbidity and mortality in the β-ENaC-Tg mouse, all without inducing any detectable signs of renal toxicity. These data suggest that S18 is the first naturally occurring ENaC antagonist to show improved preclinical efficacy in animal models of CF with no signs of renal toxicity.
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Affiliation(s)
- Shawn T Terryah
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Robert C Fellner
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Saira Ahmad
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Patrick J Moore
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Boris Reidel
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | | | - Christine S Kim
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Alaina L Garland
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | | | - Juan R Sabater
- Department of Research, Mount Sinai Medical Center , Miami Beach, Florida
| | - Jerome Carpenter
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Scott H Randell
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Cell Biology and Physiology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Mehmet Kesimer
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - William M Abraham
- Department of Research, Mount Sinai Medical Center , Miami Beach, Florida
| | - William J Arendshorst
- Cell Biology and Physiology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Robert Tarran
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Cell Biology and Physiology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
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88
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Surate Solaligue DE, Rodríguez-Castillo JA, Ahlbrecht K, Morty RE. Recent advances in our understanding of the mechanisms of late lung development and bronchopulmonary dysplasia. Am J Physiol Lung Cell Mol Physiol 2017; 313:L1101-L1153. [PMID: 28971976 DOI: 10.1152/ajplung.00343.2017] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/21/2017] [Accepted: 09/23/2017] [Indexed: 02/08/2023] Open
Abstract
The objective of lung development is to generate an organ of gas exchange that provides both a thin gas diffusion barrier and a large gas diffusion surface area, which concomitantly generates a steep gas diffusion concentration gradient. As such, the lung is perfectly structured to undertake the function of gas exchange: a large number of small alveoli provide extensive surface area within the limited volume of the lung, and a delicate alveolo-capillary barrier brings circulating blood into close proximity to the inspired air. Efficient movement of inspired air and circulating blood through the conducting airways and conducting vessels, respectively, generates steep oxygen and carbon dioxide concentration gradients across the alveolo-capillary barrier, providing ideal conditions for effective diffusion of both gases during breathing. The development of the gas exchange apparatus of the lung occurs during the second phase of lung development-namely, late lung development-which includes the canalicular, saccular, and alveolar stages of lung development. It is during these stages of lung development that preterm-born infants are delivered, when the lung is not yet competent for effective gas exchange. These infants may develop bronchopulmonary dysplasia (BPD), a syndrome complicated by disturbances to the development of the alveoli and the pulmonary vasculature. It is the objective of this review to update the reader about recent developments that further our understanding of the mechanisms of lung alveolarization and vascularization and the pathogenesis of BPD and other neonatal lung diseases that feature lung hypoplasia.
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Affiliation(s)
- David E Surate Solaligue
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and.,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - José Alberto Rodríguez-Castillo
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and.,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Katrin Ahlbrecht
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and.,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and .,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
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89
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Londino JD, Lazrak A, Collawn JF, Bebok Z, Harrod KS, Matalon S. Influenza virus infection alters ion channel function of airway and alveolar cells: mechanisms and physiological sequelae. Am J Physiol Lung Cell Mol Physiol 2017; 313:L845-L858. [PMID: 28775098 DOI: 10.1152/ajplung.00244.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 02/07/2023] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) and the amiloride-sensitive epithelial sodium channels (ENaC) are located in the apical membranes of airway and alveolar epithelial cells. These transporters play an important role in the regulation of lung fluid balance across airway and alveolar epithelia by being the conduits for chloride (Cl-) and bicarbonate ([Formula: see text]) secretion and sodium (Na+) ion absorption, respectively. The functional role of these channels in the respiratory tract is to maintain the optimum volume and ionic composition of the bronchial periciliary fluid (PCL) and alveolar lining fluid (ALF) layers. The PCL is required for proper mucociliary clearance of pathogens and debris, and the ALF is necessary for surfactant homeostasis and optimum gas exchange. Dysregulation of ion transport may lead to mucus accumulation, bacterial infections, inflammation, pulmonary edema, and compromised respiratory function. Influenza (or flu) in mammals is caused by influenza A and B viruses. Symptoms include dry cough, sore throat, and is often followed by secondary bacterial infections, accumulation of fluid in the alveolar spaces and acute lung injury. The underlying mechanisms of flu symptoms are not fully understood. This review summarizes our present knowledge of how influenza virus infections alter airway and alveolar epithelial cell CFTR and ENaC function in vivo and in vitro and the role of these changes in influenza pathogenesis.
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Affiliation(s)
- James David Londino
- Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ahmed Lazrak
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - James F Collawn
- Department of Cell, Developmental and Integrative Biology School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Zsuzsanna Bebok
- Department of Cell, Developmental and Integrative Biology School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kevin S Harrod
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
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90
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Abstract
Ischemia-reperfusion (IR)-induced acute lung injury (ALI) is implicated in several clinical conditions including lung transplantation, cardiopulmonary bypass surgery, re-expansion of collapsed lung from pneumothorax or pleural effusion and etc. IR-induced ALI remains a challenge in the current treatment. Carbonic anhydrase has important physiological function and influences on transport of CO2. Some investigators suggest that CO2 influences lung injury. Therefore, carbonic anhydrase should have the role in ALI. This study was undertaken to define the effect of a carbonic anhydrase inhibitor, acetazolamide (AZA), in IR-induced ALI, that was conducted in a rat model of isolated-perfused lung with 30 minutes of ischemia and 90 minutes of reperfusion. The animals were divided into six groups (n = 6 per group): sham, sham + AZA 200 mg/kg body weight (BW), IR, IR + AZA 100 mg/kg BW, IR + AZA 200 mg/kg BW and IR+ AZA 400 mg/kg BW. IR caused significant pulmonary micro-vascular hyper-permeability, pulmonary edema, pulmonary hypertension, neutrophilic sequestration, and an increase in the expression of pro-inflammatory cytokines. Increases in carbonic anhydrase expression and perfusate pCO2 levels were noted, while decreased Na-K-ATPase expression was noted after IR. Administration of 200mg/kg BW and 400mg/kg BW AZA significantly suppressed the expression of pro-inflammatory cytokines (TNF-α, IL-1, IL-6 and IL-17) and attenuated IR-induced lung injury, represented by decreases in pulmonary hyper-permeability, pulmonary edema, pulmonary hypertension and neutrophilic sequestration. AZA attenuated IR-induced lung injury, associated with decreases in carbonic anhydrase expression and pCO2 levels, as well as restoration of Na-K-ATPase expression.
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91
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Extraoral Taste Receptor Discovery: New Light on Ayurvedic Pharmacology. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017. [PMID: 28642799 PMCID: PMC5469997 DOI: 10.1155/2017/5435831] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
More and more research studies are revealing unexpectedly important roles of taste for health and pathogenesis of various diseases. Only recently it has been shown that taste receptors have many extraoral locations (e.g., stomach, intestines, liver, pancreas, respiratory system, heart, brain, kidney, urinary bladder, pancreas, adipose tissue, testis, and ovary), being part of a large diffuse chemosensory system. The functional implications of these taste receptors widely dispersed in various organs or tissues shed a new light on several concepts used in ayurvedic pharmacology (dravyaguna vijnana), such as taste (rasa), postdigestive effect (vipaka), qualities (guna), and energetic nature (virya). This review summarizes the significance of extraoral taste receptors and transient receptor potential (TRP) channels for ayurvedic pharmacology, as well as the biological activities of various types of phytochemical tastants from an ayurvedic perspective. The relative importance of taste (rasa), postdigestive effect (vipaka), and energetic nature (virya) as ethnopharmacological descriptors within Ayurveda boundaries will also be discussed.
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92
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Gwoździńska P, Buchbinder BA, Mayer K, Herold S, Morty RE, Seeger W, Vadász I. Hypercapnia Impairs ENaC Cell Surface Stability by Promoting Phosphorylation, Polyubiquitination and Endocytosis of β-ENaC in a Human Alveolar Epithelial Cell Line. Front Immunol 2017; 8:591. [PMID: 28588583 PMCID: PMC5440515 DOI: 10.3389/fimmu.2017.00591] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 05/04/2017] [Indexed: 01/11/2023] Open
Abstract
Acute lung injury is associated with formation of pulmonary edema leading to impaired gas exchange. Patients with acute respiratory distress syndrome (ARDS) require mechanical ventilation to improve oxygenation; however, the use of relatively low tidal volumes (to minimize further injury of the lung) often leads to further accumulation of carbon dioxide (hypercapnia). Hypercapnia has been shown to impair alveolar fluid clearance (AFC), thereby causing retention of pulmonary edema, and may lead to worse outcomes; however, the underlying molecular mechanisms remain incompletely understood. AFC is critically dependent on the epithelial sodium channel (ENaC), which drives the vectorial transport of Na+ across the alveolar epithelium. Thus, in the current study, we investigated the mechanisms by which hypercapnia effects ENaC cell surface stability in alveolar epithelial cells (AECs). Elevated CO2 levels led to polyubiquitination of β-ENaC and subsequent endocytosis of the α/β-ENaC complex in AECs, which were prevented by silencing the E3 ubiquitin ligase, Nedd4-2. Hypercapnia-induced ubiquitination and cell surface retrieval of ENaC were critically dependent on phosphorylation of the Thr615 residue of β-ENaC, which was mediated by the extracellular signal-regulated kinase (ERK)1/2. Furthermore, activation of ERK1/2 led to subsequent activation of AMP-activated protein kinase (AMPK) and c-Jun N-terminal kinase (JNK)1/2 that in turn phosphorylated Nedd4-2 at the Thr899 residue. Importantly, mutation of Thr899 to Ala markedly inhibited the CO2-induced polyubiquitination of β-ENaC and restored cell surface stability of the ENaC complex, highlighting the critical role of Nedd4-2 phosphorylation status in targeting ENaC. Collectively, our data suggest that elevated CO2 levels promote activation of the ERK/AMPK/JNK axis in a human AEC line, in which ERK1/2 phosphorylates β-ENaC whereas JNK mediates phosphorylation of Nedd4-2, thereby facilitating the channel-ligase interaction. The hypercapnia-induced ENaC dysfunction may contribute to impaired alveolar edema clearance and thus, interfering with these molecular mechanisms may improve alveolar fluid balance and lead to better outcomes in patients with ARDS.
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Affiliation(s)
- Paulina Gwoździńska
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Benno A Buchbinder
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Konstantin Mayer
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Susanne Herold
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Rory E Morty
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany.,Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Werner Seeger
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany.,Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - István Vadász
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
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93
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Abstract
PURPOSE OF REVIEW Pneumonia is a common disease that becomes severe in a subset of patients, dependent on host biology including mechanisms of immune resistance and tissue resilience. This review emphasizes discoveries in pneumonia biology from 2016, highlighting questions and directions that are especially pressing or newly emerging. RECENT FINDINGS Novel cell-cell interactions mediating innate immune responses against microbes in the lung have been elucidated, between distinct leukocyte subtypes as well as between leukocytes and the structural cells of the lung. Adaptive immunity has received growing attention for determining the outcome of pneumonia, particularly the lung resident memory cells that arise from repeated prior respiratory infections and direct heterotypic recall responses. New tissue resilience components have been identified that contribute to anti-inflammatory, proresolution, tissue-protective, and reparative regeneration pathways in the infected lung. SUMMARY Recent findings will direct research into fundamental mechanisms of lung protection. Over the longer term, manipulating these pathways has implications for clinical practice, as strategies to bolster resistance and resilience have potential to ameliorate severe pneumonia.
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Affiliation(s)
- Joseph P. Mizgerd
- Professor of Medicine, Microbiology, and Biochemistry, Director, Pulmonary Center, Boston University School of Medicine, 72 E. Concord Street, Boston, MA 02118, Phone 617-638-5201, Fax 617-638-5227,
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94
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Cui Y, Li H, Wu S, Zhao R, Du D, Ding Y, Nie H, Ji HL. Formaldehyde impairs transepithelial sodium transport. Sci Rep 2016; 6:35857. [PMID: 27762337 PMCID: PMC5071906 DOI: 10.1038/srep35857] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/06/2016] [Indexed: 01/26/2023] Open
Abstract
Unsaturated oxidative formaldehyde is a noxious aldehyde in cigarette smoke that causes edematous acute lung injury. However, the mechanistic effects of formaldehyde on lung fluid transport are still poorly understood. We examined how formaldehyde regulates human epithelial sodium channels (ENaC) in H441 and expressed in Xenopus oocytes and exposed mice in vivo. Our results showed that formaldehyde reduced mouse transalveolar fluid clearance in vivo. Formaldehyde caused a dose-dependent inhibition of amiloride-sensitive short-circuit Na+ currents in H441 monolayers and of αβγ-ENaC channel activity in oocytes. α-ENaC protein was reduced, whereas phosphorylation of the extracellular regulated protein kinases 1 and 2 (ERK1/2) increased significantly post exposure. Moreover, both α- and γ-ENaC transcripts were down-regulated. Reactive oxygen species (ROS) was elevated significantly by formaldehyde in addition to markedly augmented membrane permeability of oocytes. These data suggest that formaldehyde contributes to edematous acute lung injury by reducing transalveolar Na+ transport, through decreased ENaC activity and enhanced membrane depolarization, and by elevating ROS production over long-term exposure.
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Affiliation(s)
- Yong Cui
- Department of Anesthesiology, First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Huiming Li
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, Liaoning, China
| | - Sihui Wu
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, Liaoning, China
| | - Runzhen Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, USA
| | - Deyi Du
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, Liaoning, China
| | - Yan Ding
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, Liaoning, China
| | - Hongguang Nie
- Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, Liaoning, China
| | - Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, USA
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95
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Lucas R, Yue Q, Alli A, Duke BJ, Al-Khalili O, Thai TL, Hamacher J, Sridhar S, Lebedyeva I, Su H, Tzotzos S, Fischer B, Gameiro AF, Loose M, Chakraborty T, Shabbir W, Aufy M, Lemmens-Gruber R, Eaton DC, Czikora I. The Lectin-like Domain of TNF Increases ENaC Open Probability through a Novel Site at the Interface between the Second Transmembrane and C-terminal Domains of the α-Subunit. J Biol Chem 2016; 291:23440-23451. [PMID: 27645999 DOI: 10.1074/jbc.m116.718163] [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: 01/27/2016] [Indexed: 12/29/2022] Open
Abstract
Regulation of the epithelial sodium channel (ENaC), which regulates fluid homeostasis and blood pressure, is complex and remains incompletely understood. The TIP peptide, a mimic of the lectin-like domain of TNF, activates ENaC by binding to glycosylated residues in the extracellular loop of ENaC-α, as well as to a hitherto uncharacterized internal site. Molecular docking studies suggested three residues, Val567, Glu568, and Glu571, located at the interface between the second transmembrane and C-terminal domains of ENaC-α, as a critical site for binding of the TIP peptide. We generated Ala replacement mutants in this region of ENaC-α and examined its interaction with TIP peptide (3M, V567A/E568A/E571A; 2M, V567A/E568A; and 1M, E571A). 3M and 2M ENaC-α, but not 1M ENaC-α, displayed significantly reduced binding capacity to TIP peptide and to TNF. When overexpressed in H441 cells, 3M mutant ENaC-α formed functional channels with similar gating and density characteristics as the WT subunit and efficiently associated with the β and γ subunits in the plasma membrane. We subsequently assayed for increased open probability time and membrane expression, both of which define ENaC activity, following addition of TIP peptide. TIP peptide increased open probability time in H441 cells overexpressing wild type and 1M ENaC-α channels, but not 3M or 2M ENaC-α channels. On the other hand, TIP peptide-mediated reduction in ENaC ubiquitination was similar in cells overexpressing either WT or 3M ENaC-α subunits. In summary, this study has identified a novel site in ENaC-α that is crucial for activation of the open probability of the channel, but not membrane expression, by the lectin-like domain of TNF.
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Affiliation(s)
- Rudolf Lucas
- From the Vascular Biology Center, .,the Department of Pharmacology and Toxicology, and.,the Division of Pulmonary and Critical Care Medicine, Medical College of Georgia, Augusta, Georgia 30912
| | - Qiang Yue
- the Department of Physiology, Emory University, Atlanta, Georgia 30322
| | - Abdel Alli
- the Department of Physiology, Emory University, Atlanta, Georgia 30322.,the Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida 32610
| | | | - Otor Al-Khalili
- the Department of Physiology, Emory University, Atlanta, Georgia 30322
| | - Tiffany L Thai
- the Department of Physiology, Emory University, Atlanta, Georgia 30322
| | - Jürg Hamacher
- the Department of Pulmonology, Saarland University, D-66421 Homburg, Germany
| | | | - Iryna Lebedyeva
- the Department of Chemistry, Augusta University, Augusta, Georgia 30912
| | - Huabo Su
- From the Vascular Biology Center
| | - Susan Tzotzos
- Apeptico Research and Development, 1150 Vienna, Austria
| | | | | | - Maria Loose
- the Institute for Medical Microbiology, Justus-Liebig University, 35390 Giessen, Germany, and
| | - Trinad Chakraborty
- the Institute for Medical Microbiology, Justus-Liebig University, 35390 Giessen, Germany, and
| | - Waheed Shabbir
- the Department of Pharmacology and Toxicology, University Vienna, 1010 Vienna, Austria
| | - Mohammed Aufy
- the Department of Pharmacology and Toxicology, University Vienna, 1010 Vienna, Austria
| | - Rosa Lemmens-Gruber
- the Department of Pharmacology and Toxicology, University Vienna, 1010 Vienna, Austria
| | - Douglas C Eaton
- the Department of Physiology, Emory University, Atlanta, Georgia 30322,
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96
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Davieds B, Gross J, Berger MM, Baloğlu E, Bärtsch P, Mairbäurl H. Inhibition of alveolar Na transport and LPS causes hypoxemia and pulmonary arterial vasoconstriction in ventilated rats. Physiol Rep 2016; 4:e12985. [PMID: 27670411 PMCID: PMC5037927 DOI: 10.14814/phy2.12985] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 08/31/2016] [Indexed: 01/11/2023] Open
Abstract
Oxygen diffusion across the alveolar wall is compromised by low alveolar oxygen but also by pulmonary edema, and leads to hypoxemia and hypoxic pulmonary vasoconstriction (HPV). To test, whether inhibition of alveolar fluid reabsorption results in an increased pulmonary arterial pressure and whether this effect enhances HPV, we established a model, where anesthetized rats were ventilated with normoxic (21% O2) and hypoxic (13.5% O2) gas received aerosolized amiloride and lipopolisaccharide (LPS) to inhibit alveolar fluid reabsorption. Right ventricular systolic pressure (RVsP) was measured as an indicator of pulmonary arterial pressure. Oxygen pressure (PaO2) and saturation (SaO2) in femoral arterial blood served as indicator of oxygen diffusion across the alveolar wall. Aerosolized amiloride and bacterial LPS decreased PaO2 and SaO2 and increased RVsP even when animals were ventilated with normoxic gas. Ventilation with hypoxic gas decreased PaO2 by 35 mmHg and increased RVsP by 10 mmHg. However, combining hypoxia with amiloride and LPS did not aggravate the decrease in PaO2 and SaO2 and had no effect on the increase in RVsP relative to hypoxia alone. There was a direct relation between SaO2 and PaO2 and the RVsP under all experimental conditions. Two hours but not 1 h exposure to aerosolized amiloride and LPS in normoxia as well as hypoxia increased the lung wet-to-dry-weight ratio indicating edema formation. Together these findings indicate that inhibition of alveolar reabsorption causes pulmonary edema, impairs oxygen diffusion across the alveolar wall, and leads to an increased pulmonary arterial pressure.
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Affiliation(s)
- Bodo Davieds
- Medical Clinic VII, Sports Medicine, University of Heidelberg, Heidelberg, Germany
| | - Julian Gross
- Medical Clinic VII, Sports Medicine, University of Heidelberg, Heidelberg, Germany
| | - Marc M Berger
- Department of Anesthesiology, Perioperative and General Critical Care Medicine Salzburg General Hospital Paracelsus Medical University, Salzburg, Austria
| | - Emel Baloğlu
- Medical Clinic VII, Sports Medicine, University of Heidelberg, Heidelberg, Germany Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research (DZL), Heidelberg, Germany Department of Pharmacology, Acibadem University, Istanbul, Turkey
| | - Peter Bärtsch
- Medical Clinic VII, Sports Medicine, University of Heidelberg, Heidelberg, Germany
| | - Heimo Mairbäurl
- Medical Clinic VII, Sports Medicine, University of Heidelberg, Heidelberg, Germany Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
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97
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Jia J, Conlon TM, Ballester Lopez C, Seimetz M, Bednorz M, Zhou-Suckow Z, Weissmann N, Eickelberg O, Mall MA, Yildirim AÖ. Cigarette smoke causes acute airway disease and exacerbates chronic obstructive lung disease in neonatal mice. Am J Physiol Lung Cell Mol Physiol 2016; 311:L602-10. [PMID: 27448665 DOI: 10.1152/ajplung.00124.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/12/2016] [Indexed: 11/22/2022] Open
Abstract
Epidemiological evidence demonstrates a strong link between postnatal cigarette smoke (CS) exposure and increased respiratory morbidity in young children. However, how CS induces early onset airway disease in young children, and how it interacts with endogenous risk factors, remains poorly understood. We, therefore, exposed 10-day-old neonatal wild-type and β-epithelial sodium ion channel (β-ENaC)-transgenic mice with cystic fibrosis-like lung disease to CS for 4 days. Neonatal wild-type mice exposed to CS demonstrated increased numbers of macrophages and neutrophils in the bronchoalveolar lavage fluid (BALF), which was accompanied by increased levels of Mmp12 and Cxcl1 BALF from β-ENaC-transgenic mice contained greater numbers of macrophages, which did not increase following acute CS exposure; however, there was significant increase in airway neutrophilia compared with filtered air transgenic and CS-exposed wild-type controls. Interestingly, wild-type and β-ENaC-transgenic mice demonstrated epithelial airway and vascular remodeling following CS exposure. Morphometric analysis of lung sections revealed that CS exposure caused increased mucus accumulation in the airway lumen of neonatal β-ENaC-transgenic mice compared with wild-type controls, which was accompanied by an increase in the number of goblet cells and Muc5ac upregulation. We conclude that short-term CS exposure 1) induces acute airway disease with airway epithelial and vascular remodeling in neonatal wild-type mice; and 2) exacerbates airway inflammation, mucus hypersecretion, and mucus plugging in neonatal β-ENaC-transgenic mice with chronic lung disease. Our results in neonatal mice suggest that young children may be highly susceptible to develop airway disease in response to tobacco smoke exposure, and that adverse effects may be aggravated in children with underlying chronic lung diseases.
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Affiliation(s)
- Jie Jia
- Comprehensive Pneumology Center (CPC), Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Thomas M Conlon
- Comprehensive Pneumology Center (CPC), Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Carolina Ballester Lopez
- Comprehensive Pneumology Center (CPC), Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Michael Seimetz
- Excellence Cluster Cardio-Pulmonary System (ECCPS), Justus-Liebig-University, Giessen, Germany; Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Mariola Bednorz
- Excellence Cluster Cardio-Pulmonary System (ECCPS), Justus-Liebig-University, Giessen, Germany; Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Zhe Zhou-Suckow
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), University of Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany; and
| | - Norbert Weissmann
- Excellence Cluster Cardio-Pulmonary System (ECCPS), Justus-Liebig-University, Giessen, Germany; Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Oliver Eickelberg
- Comprehensive Pneumology Center (CPC), Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany; University Hospital of the Ludwig Maximilians University (LMU), Munich, Germany
| | - Marcus A Mall
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), University of Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany; and
| | - Ali Önder Yildirim
- Comprehensive Pneumology Center (CPC), Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany;
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98
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Liu Y, Jiang BJ, Zhao RZ, Ji HL. Epithelial Sodium Channels in Pulmonary Epithelial Progenitor and Stem Cells. Int J Biol Sci 2016; 12:1150-4. [PMID: 27570489 PMCID: PMC4997059 DOI: 10.7150/ijbs.15747] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/11/2016] [Indexed: 11/05/2022] Open
Abstract
Regeneration of the epithelium of mammalian lungs is essential for restoring normal function following injury, and various cells and mechanisms contribute to this regeneration and repair. Club cells, bronchioalveolar stem cells (BASCs), and alveolar type II epithelial cells (ATII) are dominant stem/progenitor cells for maintaining epithelial turnover and repair. Epithelial Na(+) channels (ENaC), a critical pathway for transapical salt and fluid transport, are expressed in lung epithelial progenitors, including club and ATII cells. Since ENaC activity and expression are development- and differentiation-dependent, apically located ENaC activity has therefore been used as a functional biomarker of lung injury repair. ENaC activity may be involved in the migration and differentiation of local and circulating stem/progenitor cells with diverse functions, eventually benefiting stem cells spreading to re-epithelialize injured lungs. This review summarizes the potential roles of ENaC expressed in native progenitor and stem cells in the development and regeneration of the respiratory epithelium.
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Affiliation(s)
- Yang Liu
- Institute of Lung and Molecular Therapy, Xinxiang Medical University, Xinxiang, Henan 453003, China
| | - Bi-Jie Jiang
- School of Public Health, Xinxiang Medical University, Xinxiang, Henan 453003, China
| | - Run-Zhen Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
| | - Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
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99
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Ji HL, Nie HG, Chang Y, Lian Q, Liu SL. CPT-cGMP Is A New Ligand of Epithelial Sodium Channels. Int J Biol Sci 2016; 12:359-66. [PMID: 27019621 PMCID: PMC4807156 DOI: 10.7150/ijbs.13764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/11/2015] [Indexed: 12/28/2022] Open
Abstract
Epithelial sodium channels (ENaC) are localized at the apical membrane of the epithelium, and are responsible for salt and fluid reabsorption. Renal ENaC takes up salt, thereby controlling salt content in serum. Loss-of-function ENaC mutations lead to low blood pressure due to salt-wasting, while gain-of-function mutations cause impaired sodium excretion and subsequent hypertension as well as hypokalemia. ENaC activity is regulated by intracellular and extracellular signals, including hormones, neurotransmitters, protein kinases, and small compounds. Cyclic nucleotides are broadly involved in stimulating protein kinase A and protein kinase G signaling pathways, and, surprisingly, also appear to have a role in regulating ENaC. Increasing evidence suggests that the cGMP analog, CPT-cGMP, activates αβγ-ENaC activity reversibly through an extracellular pathway in a dose-dependent manner. Furthermore, the parachlorophenylthio moiety and ribose 2'-hydroxy group of CPT-cGMP are essential for facilitating the opening of ENaC channels by this compound. Serving as an extracellular ligand, CPT-cGMP eliminates sodium self-inhibition, which is a novel mechanism for stimulating salt reabsorption in parallel to the traditional NO/cGMP/PKG signal pathway. In conclusion, ENaC may be a druggable target for CPT-cGMP, leading to treatments for kidney malfunctions in salt reabsorption.
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Affiliation(s)
- Hong-Long Ji
- 1. Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
| | - Hong-Guang Nie
- 2. Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang 110001, China
| | - Yongchang Chang
- 3. Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, 85013, USA
| | - Qizhou Lian
- 4. Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Shan-Lu Liu
- 5. Department of Molecular Microbiology and Immunology, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
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100
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Ludwig MG, Seuwen K, Bridges JP. Adhesion GPCR Function in Pulmonary Development and Disease. Handb Exp Pharmacol 2016; 234:309-327. [PMID: 27832494 DOI: 10.1007/978-3-319-41523-9_14] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Classic G-protein-coupled receptors (GPCRs) control multiple aspects of pulmonary physiology as demonstrated by loss-of-function experiments in mice and pharmacologic targeting of GPCRs for treatment of several pulmonary diseases. Emerging data demonstrate critical roles for members of the adhesion GPCR (aGPCR) family in pulmonary development, homeostasis, and disease. Although this field is still in its infancy, this chapter will review all available data regarding aGPCRs in pulmonary biology, with a particular focus on the aGPCR for which the most substantial data to date exist: Adgrf5.
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Affiliation(s)
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, 4056, Switzerland
| | - James P Bridges
- Department of Pediatrics, Section of Pulmonary Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA. .,Division of Pulmonary Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, ML7029, Cincinnati, OH, 45229, USA.
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