1
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Thakku Sivakumar D, Jain K, Alfehaid N, Wang Y, Teng X, Fischer W, Engel T. The Purinergic P2X7 Receptor as a Target for Adjunctive Treatment for Drug-Refractory Epilepsy. Int J Mol Sci 2024; 25:6894. [PMID: 39000004 PMCID: PMC11241490 DOI: 10.3390/ijms25136894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/06/2024] [Accepted: 06/17/2024] [Indexed: 07/14/2024] Open
Abstract
Epilepsy is one of the most common neurological diseases worldwide. Anti-seizure medications (ASMs) with anticonvulsants remain the mainstay of epilepsy treatment. Currently used ASMs are, however, ineffective to suppress seizures in about one third of all patients. Moreover, ASMs show no significant impact on the pathogenic mechanisms involved in epilepsy development or disease progression and may cause serious side-effects, highlighting the need for the identification of new drug targets for a more causal therapy. Compelling evidence has demonstrated a role for purinergic signalling, including the nucleotide adenosine 5'-triphosphate (ATP) during the generation of seizures and epilepsy. Consequently, drugs targeting specific ATP-gated purinergic receptors have been suggested as promising treatment options for epilepsy including the cationic P2X7 receptor (P27XR). P2X7R protein levels have been shown to be increased in the brain of experimental models of epilepsy and in the resected brain tissue of patients with epilepsy. Animal studies have provided evidence that P2X7R blocking can reduce the severity of acute seizures and the epileptic phenotype. The current review will provide a brief summary of recent key findings on P2X7R signalling during seizures and epilepsy focusing on the potential clinical use of treatments based on the P2X7R as an adjunctive therapeutic strategy for drug-refractory seizures and epilepsy.
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Affiliation(s)
- Divyeshz Thakku Sivakumar
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Krishi Jain
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Noura Alfehaid
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Yitao Wang
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
- International College of Pharmaceutical Innovation, Soochow University, Suzhou 215123, China
| | - Xinchen Teng
- International College of Pharmaceutical Innovation, Soochow University, Suzhou 215123, China
| | | | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
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2
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Herbst CJ, Lopez-Rodriguez E, Gluhovic V, Schulz S, Brandt R, Timm S, Abledu J, Falivene J, Pennitz P, Kirsten H, Nouailles G, Witzenrath M, Ochs M, Kuebler WM. Characterization of Commercially Available Human Primary Alveolar Epithelial Cells. Am J Respir Cell Mol Biol 2024; 70:339-350. [PMID: 38207121 DOI: 10.1165/rcmb.2023-0320ma] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/10/2024] [Indexed: 01/13/2024] Open
Abstract
In vitro lung research requires appropriate cell culture models that adequately mimic in vivo structure and function. Previously, researchers extensively used commercially available and easily expandable A549 and NCI-H441 cells, which replicate some but not all features of alveolar epithelial cells. Specifically, these cells are often restricted by terminally altered expression while lacking important alveolar epithelial characteristics. Of late, human primary alveolar epithelial cells (hPAEpCs) have become commercially available but are so far poorly specified. Here, we applied a comprehensive set of technologies to characterize their morphology, surface marker expression, transcriptomic profile, and functional properties. At optimized seeding numbers of 7,500 cells per square centimeter and growth at a gas-liquid interface, hPAEpCs formed regular monolayers with tight junctions and amiloride-sensitive transepithelial ion transport. Electron microscopy revealed lamellar body and microvilli formation characteristic for alveolar type II cells. Protein and single-cell transcriptomic analyses revealed expression of alveolar type I and type II cell markers; yet, transcriptomic data failed to detect NKX2-1, an important transcriptional regulator of alveolar cell differentiation. With increasing passage number, hPAEpCs transdifferentiated toward alveolar-basal intermediates characterized as SFTPC-, KRT8high, and KRT5- cells. In spite of marked changes in the transcriptome as a function of passaging, Uniform Manifold Approximation and Projection plots did not reveal major shifts in cell clusters, and epithelial permeability was unaffected. The present work delineates optimized culture conditions, cellular characteristics, and functional properties of commercially available hPAEpCs. hPAEpCs may provide a useful model system for studies on drug delivery, barrier function, and transepithelial ion transport in vitro.
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Affiliation(s)
- Christopher J Herbst
- Institute of Physiology
- German Center for Cardiovascular Research, Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Berlin, Germany
- German Center for Lung Research, Deutsches Zentrum für Lungenforschung (DZL), Berlin, Germany
| | | | | | | | | | - Sara Timm
- Core Facility Electron Microscopy, and
| | | | | | - Peter Pennitz
- Department of Infectious Diseases, Respiratory Medicine and Critical Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Holger Kirsten
- Institute for Medical Informatics, Statistics, and Epidemiology, University of Leipzig, Leipzig, Germany; and
| | - Geraldine Nouailles
- Department of Infectious Diseases, Respiratory Medicine and Critical Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Martin Witzenrath
- Department of Infectious Diseases, Respiratory Medicine and Critical Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Matthias Ochs
- Institute of Functional Anatomy
- Core Facility Electron Microscopy, and
- German Center for Lung Research, Deutsches Zentrum für Lungenforschung (DZL), Berlin, Germany
| | - Wolfgang M Kuebler
- Institute of Physiology
- German Center for Cardiovascular Research, Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Berlin, Germany
- German Center for Lung Research, Deutsches Zentrum für Lungenforschung (DZL), Berlin, Germany
- Keenan Research Centre, St. Michael's Hospital, and
- Departments of Surgery and
- Physiology, University of Toronto, Toronto, Ontario, Canada
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3
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Tang S, De Jesus AC, Chavez D, Suthakaran S, Moore SK, Suthakaran K, Homami S, Rathnasinghe R, May AJ, Schotsaert M, Britto CJ, Bhattacharya J, Hook JL. Rescue of alveolar wall liquid secretion blocks fatal lung injury due to influenza-staphylococcal coinfection. J Clin Invest 2023; 133:e163402. [PMID: 37581936 PMCID: PMC10541650 DOI: 10.1172/jci163402] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/10/2023] [Indexed: 08/17/2023] Open
Abstract
Secondary lung infection by inhaled Staphylococcus aureus (SA) is a common and lethal event for individuals infected with influenza A virus (IAV). How IAV disrupts host defense to promote SA infection in lung alveoli, where fatal lung injury occurs, is not known. We addressed this issue using real-time determinations of alveolar responses to IAV in live, intact, perfused lungs. Our findings show that IAV infection blocked defensive alveolar wall liquid (AWL) secretion and induced airspace liquid absorption, thereby reversing normal alveolar liquid dynamics and inhibiting alveolar clearance of inhaled SA. Loss of AWL secretion resulted from inhibition of the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel in the alveolar epithelium, and airspace liquid absorption was caused by stimulation of the alveolar epithelial Na+ channel (ENaC). Loss of AWL secretion promoted alveolar stabilization of inhaled SA, but rescue of AWL secretion protected against alveolar SA stabilization and fatal SA-induced lung injury in IAV-infected mice. These findings reveal a central role for AWL secretion in alveolar defense against inhaled SA and identify AWL inhibition as a critical mechanism of IAV lung pathogenesis. AWL rescue may represent a new therapeutic approach for IAV-SA coinfection.
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Affiliation(s)
- Stephanie Tang
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
- Graduate School of Biomedical Sciences
| | - Ana Cassandra De Jesus
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Deebly Chavez
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Sayahi Suthakaran
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
- Graduate School of Biomedical Sciences
| | - Sarah K.L. Moore
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Keshon Suthakaran
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Sonya Homami
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
- Graduate School of Biomedical Sciences
| | - Raveen Rathnasinghe
- Graduate School of Biomedical Sciences
- Global Health and Emerging Pathogens Institute, Department of Microbiology
| | - Alison J. May
- Department of Cell, Developmental and Regenerative Biology
- Department of Otolaryngology, and
- Institute of Regenerative Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Michael Schotsaert
- Global Health and Emerging Pathogens Institute, Department of Microbiology
| | - Clemente J. Britto
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jahar Bhattacharya
- Departments of Medicine and Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York, USA
| | - Jaime L. Hook
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
- Global Health and Emerging Pathogens Institute, Department of Microbiology
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4
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Taenaka H, Matthay MA. Mechanisms of impaired alveolar fluid clearance. Anat Rec (Hoboken) 2023:10.1002/ar.25166. [PMID: 36688689 PMCID: PMC10564110 DOI: 10.1002/ar.25166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/09/2022] [Accepted: 01/04/2023] [Indexed: 01/24/2023]
Abstract
Impaired alveolar fluid clearance (AFC) is an important cause of alveolar edema fluid accumulation in patients with acute respiratory distress syndrome (ARDS). Alveolar edema leads to insufficient gas exchange and worse clinical outcomes. Thus, it is important to understand the pathophysiology of impaired AFC in order to develop new therapies for ARDS. Over the last few decades, multiple experimental studies have been done to understand the molecular, cellular, and physiological mechanisms that regulate AFC in the normal and the injured lung. This review provides a review of AFC in the normal lung, focuses on the mechanisms of impaired AFC, and then outlines the regulation of AFC. Finally, we summarize ongoing challenges and possible future research that may offer promising therapies for ARDS.
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Affiliation(s)
- Hiroki Taenaka
- Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco, California, USA
- Department of Anesthesia, Cardiovascular Research Institute, University of California, San Francisco, California, USA
- Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Michael A. Matthay
- Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco, California, USA
- Department of Anesthesia, Cardiovascular Research Institute, University of California, San Francisco, California, USA
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5
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Tao H, Xu Y, Zhang S. The Role of Macrophages and Alveolar Epithelial Cells in the Development of ARDS. Inflammation 2023; 46:47-55. [PMID: 36048270 PMCID: PMC9435414 DOI: 10.1007/s10753-022-01726-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 07/25/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022]
Abstract
Acute lung injury (ALI) usually causes acute respiratory distress syndrome (ARDS), or even death in critical ill patients. Immune cell infiltration in inflamed lungs is an important hallmark of ARDS. Macrophages are a type of immune cell that participate in the entire pathogenic trajectory of ARDS and most prominently via their interactions with lung alveolar epithelial cells (AECs). In the early stage of ARDS, classically activated macrophages secrete pro-inflammatory cytokines to clearance of the pathogens which may damage alveolar AECs cell structure and result in cell death. Paradoxically, in late stage of ARDS, anti-inflammatory cytokines secreted by alternatively activated macrophages dampen the inflammation response and promote epithelial regeneration and alveolar structure remodeling. In this review, we discuss the important role of macrophages and AECs in the progression of ARDS.
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Affiliation(s)
- Huan Tao
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430033, China
| | - Younian Xu
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430033, China.
| | - Shihai Zhang
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430033, China.
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6
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Wong ZW, Engel T. More than a drug target: Purinergic signalling as a source for diagnostic tools in epilepsy. Neuropharmacology 2023; 222:109303. [PMID: 36309046 DOI: 10.1016/j.neuropharm.2022.109303] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/15/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Epilepsy is one of the most common and disabling chronic neurological diseases affecting people of all ages. Major challenges of epilepsy management include the persistently high percentage of drug-refractoriness among patients, the absence of disease-modifying treatments, and its diagnosis and prognosis. To date, long-term video-electroencephalogram (EEG) recordings remain the gold standard for an epilepsy diagnosis. However, this is very costly, has low throughput, and in some instances has very limited availability. Therefore, much effort is put into the search for non-invasive diagnostic tests. Purinergic signalling, via extracellularly released adenosine triphosphate (ATP), is gaining increasing traction as a therapeutic strategy for epilepsy treatment which is supported by evidence from both experimental models and patients. This includes in particular the ionotropic P2X7 receptor. Besides that, other components from the ATPergic signalling cascade such as the metabotropic P2Y receptors (e.g., P2Y1 receptor) and ATP-release channels (e.g., pannexin-1), have also been shown to contribute to seizures and epilepsy. In addition to the therapeutic potential of purinergic signalling, emerging evidence has also shown its potential as a diagnostic tool. Following seizures and epilepsy, the concentration of purines in the blood and the expression of different compounds of the purinergic signalling cascade are significantly altered. Herein, this review will provide a detailed discussion of recent findings on the diagnostic potential of purinergic signalling for epilepsy management and the prospect of translating it for clinical application. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.
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Affiliation(s)
- Zheng Wei Wong
- School of Pharmacy, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland; FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland.
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7
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Yue P, Zhou W, Huang G, Lei F, Chen Y, Ma Z, Chen L, Yang M. Nanocrystals based pulmonary inhalation delivery system: advance and challenge. Drug Deliv 2022; 29:637-651. [PMID: 35188021 PMCID: PMC8865109 DOI: 10.1080/10717544.2022.2039809] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pulmonary inhalation administration is an ideal approach to locally treat lung disease and to achieve systemic administration for other diseases. However, the complex nature of the structural characteristics of the lungs often results in the difficulty in the development of lung inhalation preparations. Nanocrystals technology provides a potential formulation strategy for the pulmonary delivery of poorly soluble drugs, owing to the decreased particle size of drug, which is a potential approach to overcome the physiological barrier existing in the lungs and significantly increased bioavailability of drugs. The pulmonary inhalation administration has attracted considerable attentions in recent years. This review discusses the barriers for pulmonary drug delivery and the recent advance of the nanocrystals in pulmonary inhalation delivery. The presence of nanocrystals opens up new prospects for the development of novel pulmonary delivery system. The particle size control, physical instability, potential cytotoxicity, and clearance mechanism of inhaled nanocrystals based formulations are the major considerations in formulation development.
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Affiliation(s)
- Pengfei Yue
- Key Lab of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, People's Republic of China
| | - Weicheng Zhou
- Key Lab of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, People's Republic of China
| | - Guiting Huang
- Key Lab of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, People's Republic of China
| | - Fangfang Lei
- Key Lab of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, People's Republic of China
| | - Yingchong Chen
- Key Lab of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, People's Republic of China
| | - Zhilin Ma
- Langka Biotechnology (Shanghai) Co., Ltd, Shanghai, People's Republic of China
| | - Liru Chen
- Beijing Hospital, Beijing, People's Republic of China
| | - Ming Yang
- Key Lab of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, People's Republic of China
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8
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Lucas R, Hadizamani Y, Enkhbaatar P, Csanyi G, Caldwell RW, Hundsberger H, Sridhar S, Lever AA, Hudel M, Ash D, Ushio-Fukai M, Fukai T, Chakraborty T, Verin A, Eaton DC, Romero M, Hamacher J. Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance. Front Physiol 2022; 12:793251. [PMID: 35264975 PMCID: PMC8899333 DOI: 10.3389/fphys.2021.793251] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/30/2021] [Indexed: 02/04/2023] Open
Abstract
Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States,*Correspondence: Rudolf Lucas,
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung Bern, Bern, Switzerland,Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, Bern, Switzerland
| | - Perenlei Enkhbaatar
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, United States
| | - Gabor Csanyi
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States
| | - Robert W. Caldwell
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States
| | - Harald Hundsberger
- Department of Medical Biotechnology, University of Applied Sciences, Krems, Austria,Department of Dermatology, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Supriya Sridhar
- Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Alice Ann Lever
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Martina Hudel
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Dipankar Ash
- Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Masuko Ushio-Fukai
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Tohru Fukai
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Alexander Verin
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Douglas C. Eaton
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Maritza Romero
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Department of Anesthesiology and Perioperative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung Bern, Bern, Switzerland,Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, Bern, Switzerland,Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine, and Environmental Medicine, Faculty of Medicine, University Medical Centre of the Saarland, Saarland University, Homburg, Germany,Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, Homburg, Germany,Jürg Hamacher,
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9
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Liu J, Dean DA. Gene Therapy for Acute Respiratory Distress Syndrome. Front Physiol 2022; 12:786255. [PMID: 35111077 PMCID: PMC8801611 DOI: 10.3389/fphys.2021.786255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a devastating clinical syndrome that leads to acute respiratory failure and accounts for over 70,000 deaths per year in the United States alone, even prior to the COVID-19 pandemic. While its molecular details have been teased apart and its pathophysiology largely established over the past 30 years, relatively few pharmacological advances in treatment have been made based on this knowledge. Indeed, mortality remains very close to what it was 30 years ago. As an alternative to traditional pharmacological approaches, gene therapy offers a highly controlled and targeted strategy to treat the disease at the molecular level. Although there is no single gene or combination of genes responsible for ARDS, there are a number of genes that can be targeted for upregulation or downregulation that could alleviate many of the symptoms and address the underlying mechanisms of this syndrome. This review will focus on the pathophysiology of ARDS and how gene therapy has been used for prevention and treatment. Strategies for gene delivery to the lung, such as barriers encountered during gene transfer, specific classes of genes that have been targeted, and the outcomes of these approaches on ARDS pathogenesis and resolution will be discussed.
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Affiliation(s)
- Jing Liu
- Department of Pediatrics, University of Rochester, Rochester, NY, United States
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, United States
| | - David A. Dean
- Department of Pediatrics, University of Rochester, Rochester, NY, United States
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, United States
- *Correspondence: David A. Dean,
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10
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Tung YC, Wang CK, Huang YK, Huang CK, Peng CC, Patra B, Chen HK, Tsao PN, Ling TY. Identifying distinct oxygen diffusivity through type I pneumocyte-like cell layers using microfluidic device. Talanta 2022; 236:122882. [PMID: 34635262 DOI: 10.1016/j.talanta.2021.122882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/07/2021] [Accepted: 09/11/2021] [Indexed: 12/22/2022]
Abstract
Oxygen is necessary for cellular respiration in aerobic organisms. In animals, such as human, inhaled oxygen moves from the alveoli to the blood through alveolar epithelium into pulmonary capillaries. Up to now, different studies have been reported to examine experimental oxygen diffusivity for simple membrane or single-celled organisms; however, devices capable of precisely characterizing oxygen transportation through cell layers with dimensions similar to their physiological ones have not been developed. In this study, we establish an integrated approach exploiting a multi-layer microfluidic device and relative fluorescence lifetime detection apparatus to reliably measure oxygen diffusivity through a cell layer. In the experiments, different types of cells, including A549 and 3T3 cell lines, lung stem/progenitor cells, and the differentiated type I pneumocyte-like cells, are used to form cell layers within the devices for their oxygen diffusivity evaluation. A distinct facilitated oxygen transportation behavior of the differentiated type I pneumocyte-like cells that has never been discussed before is identified using the approach. The study offered a new in vitro approach to evaluate the oxygen diffusivity across cell layers in a microfluidic device and open a door to construct more physiologically meaningful in vitro model system to study respiratory systems.
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Affiliation(s)
- Yi-Chung Tung
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Chien-Kai Wang
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Yung-Kang Huang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Cheng-Kai Huang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Chien-Chung Peng
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Bishnubrata Patra
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Hung-Kuan Chen
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan; Division of Neonatology, Department of Pediatrics, National Taiwan University Hospital, Taipei, 10041, Taiwan
| | - Po-Nien Tsao
- Division of Neonatology, Department of Pediatrics, National Taiwan University Hospital, Taipei, 10041, Taiwan; Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, 10051, Taiwan.
| | - Thai-Yen Ling
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan; Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, 10051, Taiwan.
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11
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Xie X, Yu T, Hou Y, Han A, Ding Y, Nie H, Cui Y. Ferulic acid ameliorates lipopolysaccharide-induced tracheal injury via cGMP/PKGII signaling pathway. Respir Res 2021; 22:308. [PMID: 34863181 PMCID: PMC8642995 DOI: 10.1186/s12931-021-01897-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 11/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tracheal injury is a common clinical condition that still lacks an effective therapy at present. Stimulation of epithelial sodium channel (ENaC) increases Na+ transport, which is a driving force to keep tracheal mucosa free edema fluid during tracheal injury. Ferulic acid (FA) has been proved to be effective in many respiratory diseases through exerting anti-oxidant, anti-inflammatory, and anti-thrombotic effects. However, these studies rarely involve the level of ion transport, especially ENaC. METHODS C57BL/J male mice were treated intraperitoneally with normal saline or FA (100 mg/kg) 12 h before, and 12 h after intratracheal administration of lipopolysaccharide (LPS, 5 mg/kg), respectively. The effects of FA on tracheal injury were not only assessed through HE staining, immunofluorescence assay, and protein/mRNA expressions of ENaC located on tracheas, but also evaluated by the function of ENaC in mouse tracheal epithelial cells (MTECs). Besides, to explore the detailed mechanism about FA involved in LPS-induced tracheal injury, the content of cyclic guanosine monophosphate (cGMP) was measured, and Rp-cGMP (cGMP inhibitor) or cGMP-dependent protein kinase II (PKGII)-siRNA (siPKGII) were applied in primary MTECs, respectively. RESULTS Histological examination results demonstrated that tracheal injury was obviously attenuated by pretreatment of FA. Meanwhile, FA could reverse LPS-induced reduction of both protein/mRNA expressions and ENaC activity. ELISA assay verified cGMP content was increased by FA, and administration of Rp-cGMP or transfection of siPKGII could reverse the FA up-regulated ENaC protein expression in MTECs. CONCLUSIONS Ferulic acid can attenuate LPS-induced tracheal injury through up-regulation of ENaC at least partially via the cGMP/PKGII pathway, which may provide a promising new direction for preventive and therapeutic strategy in tracheal injury.
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Affiliation(s)
- Xiaoyong Xie
- Department of Anesthesiology, the First Hospital of China Medical University, Shenyang, 110001, China.,Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China
| | - Tong Yu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China
| | - Aixin Han
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China.
| | - Yong Cui
- Department of Anesthesiology, the First Hospital of China Medical University, Shenyang, 110001, China.
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12
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The role of pulmonary ORCC and CLC-2 channels in the response to oxidative stress. Mol Cell Toxicol 2021. [DOI: 10.1007/s13273-021-00137-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
Background
Exposure of human lung epithelial cells to the oxidant pollutant ozone (O3) alters cell Cl− currents inducing an outward rectifier effect. Among the various Cl− channels, ClC-2 and ORCC seemed to be involved in this response.
Objectives
To identify the channel related to O3 induced current changes.
Results
Down regulating the expression of ORCC and ClC-2 genes and analyzing the membrane current show that the enhancement of the current disappeared when ORCC was silenced. The contribution of ORCC and ClC-2 channels in control and O3 treated cells was obtained by a mathematical approach.
Conclusion
We suggest that O3 activates ORCC channels and slightly inhibited ClC-2 channels in the negative voltage range. These findings open the possibility of identifying the biomolecular changes induced by O3 allowing a possible pharmacological intervention towards chloride current due to oxidative stress.
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13
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Sun AM, Hoffman T, Luu BQ, Ashammakhi N, Li S. Application of lung microphysiological systems to COVID-19 modeling and drug discovery: a review. Biodes Manuf 2021; 4:757-775. [PMID: 34178414 PMCID: PMC8213042 DOI: 10.1007/s42242-021-00136-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/13/2021] [Indexed: 01/08/2023]
Abstract
There is a pressing need for effective therapeutics for coronavirus disease 2019 (COVID-19), the respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The process of drug development is a costly and meticulously paced process, where progress is often hindered by the failure of initially promising leads. To aid this challenge, in vitro human microphysiological systems need to be refined and adapted for mechanistic studies and drug screening, thereby saving valuable time and resources during a pandemic crisis. The SARS-CoV-2 virus attacks the lung, an organ where the unique three-dimensional (3D) structure of its functional units is critical for proper respiratory function. The in vitro lung models essentially recapitulate the distinct tissue structure and the dynamic mechanical and biological interactions between different cell types. Current model systems include Transwell, organoid and organ-on-a-chip or microphysiological systems (MPSs). We review models that have direct relevance toward modeling the pathology of COVID-19, including the processes of inflammation, edema, coagulation, as well as lung immune function. We also consider the practical issues that may influence the design and fabrication of MPS. The role of lung MPS is addressed in the context of multi-organ models, and it is discussed how high-throughput screening and artificial intelligence can be integrated with lung MPS to accelerate drug development for COVID-19 and other infectious diseases.
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Affiliation(s)
- Argus M. Sun
- Department of Bioengineering, Samueli School of Engineering, University of California - Los Angeles, 420 Westwood Plaza 5121 Engineering V University of California, Los Angeles, CA 90095-1600 USA
- UC San Diego Healthcare, UCSD, La Jolla, CA 92037 USA
| | - Tyler Hoffman
- Department of Bioengineering, Samueli School of Engineering, University of California - Los Angeles, 420 Westwood Plaza 5121 Engineering V University of California, Los Angeles, CA 90095-1600 USA
| | - Bao Q. Luu
- Pulmonary Diseases and Critical Care, Scripps Green Hospital, Scripps Health, La Jolla, CA 92037 USA
| | - Nureddin Ashammakhi
- Department of Bioengineering, Samueli School of Engineering, University of California - Los Angeles, 420 Westwood Plaza 5121 Engineering V University of California, Los Angeles, CA 90095-1600 USA
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 USA
| | - Song Li
- Department of Bioengineering, Samueli School of Engineering, University of California - Los Angeles, 420 Westwood Plaza 5121 Engineering V University of California, Los Angeles, CA 90095-1600 USA
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095 USA
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14
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Strandvik B. Is the ENaC Dysregulation in CF an Effect of Protein-Lipid Interaction in the Membranes? Int J Mol Sci 2021; 22:ijms22052739. [PMID: 33800499 PMCID: PMC7962953 DOI: 10.3390/ijms22052739] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 02/28/2021] [Accepted: 03/05/2021] [Indexed: 12/26/2022] Open
Abstract
While approximately 2000 mutations have been discovered in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR), only a small amount (about 10%) is associated with clinical cystic fibrosis (CF) disease. The discovery of the association between CFTR and the hyperactive epithelial sodium channel (ENaC) has raised the question of the influence of ENaC on the clinical CF phenotype. ENaC disturbance contributes to the pathological secretion, and overexpression of one ENaC subunit, the β-unit, can give a CF-like phenotype in mice with normal acting CFTR. The development of ENaC channel modulators is now in progress. Both CFTR and ENaC are located in the cell membrane and are influenced by its lipid configuration. Recent studies have emphasized the importance of the interaction of lipids and these proteins in the membranes. Linoleic acid deficiency is the most prevailing lipid abnormality in CF, and linoleic acid is an important constituent of membranes. The influence on sodium excretion by linoleic acid supplementation indicates that lipid-protein interaction is of importance for the clinical pathophysiology in CF. Further studies of this association can imply a simple clinical adjuvant in CF therapy.
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Affiliation(s)
- Birgitta Strandvik
- Department of Biosciences and Nutrition, Karolinska Institutet NEO, 14183 Stockholm, Sweden
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15
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Weidenfeld S, Chupin C, Langner DI, Zetoun T, Rozowsky S, Kuebler WM. Sodium-coupled neutral amino acid transporter SNAT2 counteracts cardiogenic pulmonary edema by driving alveolar fluid clearance. Am J Physiol Lung Cell Mol Physiol 2021; 320:L486-L497. [PMID: 33439101 DOI: 10.1152/ajplung.00461.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The constant transport of ions across the alveolar epithelial barrier regulates alveolar fluid homeostasis. Dysregulation or inhibition of Na+ transport causes fluid accumulation in the distal airspaces resulting in impaired gas exchange and respiratory failure. Previous studies have primarily focused on the critical role of amiloride-sensitive epithelial sodium channel (ENaC) in alveolar fluid clearance (AFC), yet activation of ENaC failed to attenuate pulmonary edema in clinical trials. Since 40% of AFC is amiloride-insensitive, Na+ channels/transporters other than ENaC such as Na+-coupled neutral amino acid transporters (SNATs) may provide novel therapeutic targets. Here, we identified a key role for SNAT2 (SLC38A2) in AFC and pulmonary edema resolution. In isolated perfused mouse and rat lungs, pharmacological inhibition of SNATs by HgCl2 and α-methylaminoisobutyric acid (MeAIB) impaired AFC. Quantitative RT-PCR identified SNAT2 as the highest expressed System A transporter in pulmonary epithelial cells. Pharmacological inhibition or siRNA-mediated knockdown of SNAT2 reduced transport of l-alanine across pulmonary epithelial cells. Homozygous Slc38a2-/- mice were subviable and died shortly after birth with severe cyanosis. Isolated lungs of Slc38a2+/- mice developed higher wet-to-dry weight ratios (W/D) as compared to wild type (WT) in response to hydrostatic stress. Similarly, W/D ratios were increased in Slc38a2+/- mice as compared to controls in an acid-induced lung injury model. Our results identify SNAT2 as a functional transporter for Na+ and neutral amino acids in pulmonary epithelial cells with a relevant role in AFC and the resolution of lung edema. Activation of SNAT2 may provide a new therapeutic strategy to counteract and/or reverse pulmonary edema.
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Affiliation(s)
- Sarah Weidenfeld
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Cécile Chupin
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | | | - Tamador Zetoun
- Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Simon Rozowsky
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Wolfgang M Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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16
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Chaurasiya B, Zhao YY. Dry Powder for Pulmonary Delivery: A Comprehensive Review. Pharmaceutics 2020; 13:pharmaceutics13010031. [PMID: 33379136 PMCID: PMC7824629 DOI: 10.3390/pharmaceutics13010031] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/12/2020] [Accepted: 12/17/2020] [Indexed: 01/04/2023] Open
Abstract
The pulmonary route has long been used for drug administration for both local and systemic treatment. It possesses several advantages, which can be categorized into physiological, i.e., large surface area, thin epithelial membrane, highly vascularized, limited enzymatic activity, and patient convenience, i.e., non-invasive, self-administration over oral and systemic routes of drug administration. However, the formulation of dry powder for pulmonary delivery is often challenging due to restrictions on aerodynamic size and the lung’s lower tolerance capacity in comparison with an oral route of drug administration. Various physicochemical properties of dry powder play a major role in the aerosolization, deposition, and clearance along the respiratory tract. To prepare suitable particles with optimal physicochemical properties for inhalation, various manufacturing methods have been established. The most frequently used industrial methods are milling and spray-drying, while several other alternative methods such as spray-freeze-drying, supercritical fluid, non-wetting templates, inkjet-printing, thin-film freezing, and hot-melt extrusion methods are also utilized. The aim of this review is to provide an overview of the respiratory tract structure, particle deposition patterns, and possible drug-clearance mechanisms from the lungs. This review also includes the physicochemical properties of dry powder, various techniques used for the preparation of dry powders, and factors affecting the clinical efficacy, as well as various challenges that need to be addressed in the future.
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Affiliation(s)
- Birendra Chaurasiya
- Program for Lung and Vascular Biology, Stanley Manne Children’s Research Institute, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA;
- Department of Pediatrics, Division of Critical Care, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - You-Yang Zhao
- Program for Lung and Vascular Biology, Stanley Manne Children’s Research Institute, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA;
- Department of Pediatrics, Division of Critical Care, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Pharmacology, and Department of Medicine (Division of Pulmonary and Critical Care Division), Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Correspondence: ; Tel.: +1-(312)-503-7593
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17
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Menéndez Méndez A, Smith J, Engel T. Neonatal Seizures and Purinergic Signalling. Int J Mol Sci 2020; 21:ijms21217832. [PMID: 33105750 PMCID: PMC7660091 DOI: 10.3390/ijms21217832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023] Open
Abstract
Neonatal seizures are one of the most common comorbidities of neonatal encephalopathy, with seizures aggravating acute injury and clinical outcomes. Current treatment can control early life seizures; however, a high level of pharmacoresistance remains among infants, with increasing evidence suggesting current anti-seizure medication potentiating brain damage. This emphasises the need to develop safer therapeutic strategies with a different mechanism of action. The purinergic system, characterised by the use of adenosine triphosphate and its metabolites as signalling molecules, consists of the membrane-bound P1 and P2 purinoreceptors and proteins to modulate extracellular purine nucleotides and nucleoside levels. Targeting this system is proving successful at treating many disorders and diseases of the central nervous system, including epilepsy. Mounting evidence demonstrates that drugs targeting the purinergic system provide both convulsive and anticonvulsive effects. With components of the purinergic signalling system being widely expressed during brain development, emerging evidence suggests that purinergic signalling contributes to neonatal seizures. In this review, we first provide an overview on neonatal seizure pathology and purinergic signalling during brain development. We then describe in detail recent evidence demonstrating a role for purinergic signalling during neonatal seizures and discuss possible purine-based avenues for seizure suppression in neonates.
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Affiliation(s)
- Aida Menéndez Méndez
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
| | - Jonathon Smith
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Tobias Engel
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
- Correspondence: ; Tel.: +35-314-025-199
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18
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Liu Q, Guan J, Qin L, Zhang X, Mao S. Physicochemical properties affecting the fate of nanoparticles in pulmonary drug delivery. Drug Discov Today 2020; 25:150-159. [DOI: 10.1016/j.drudis.2019.09.023] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/01/2019] [Accepted: 09/27/2019] [Indexed: 01/27/2023]
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19
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Turck D, Castenmiller J, de Henauw S, Hirsch-Ernst KI, Kearney J, Knutsen HK, Maciuk A, Mangelsdorf I, McArdle HJ, Pelaez C, Pentieva K, Siani A, Thies F, Tsabouri S, Vinceti M, Aggett P, Fairweather-Tait S, Martin A, Przyrembel H, de Sesmaisons-Lecarré A, Naska A. Dietary reference values for chloride. EFSA J 2019; 17:e05779. [PMID: 32626426 PMCID: PMC7009052 DOI: 10.2903/j.efsa.2019.5779] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) has derived dietary reference values (DRVs) for chloride. There are no appropriate biomarkers of chloride status, no balance studies and no adequate evidence on the relationship between chloride intake and health outcomes that can be used to set DRVs for chloride. There is a close relationship between sodium and chloride balances in the body. Sodium chloride is the main source of both electrolytes in European diets and similar urinary excretion levels of sodium and chloride (on a molar basis) are typically observed in Western populations. Hence, the Panel considered that reference values for chloride can be set at values equimolar to the reference values for sodium for all population groups, and are as follows: 1.7 g/day for children aged 1-3 years, 2.0 g/day for children aged 4-6 years, 2.6 g/day for children aged 7-10 years, 3.1 g/day for children aged 11-17 years and 3.1 g/day for adults including pregnant and lactating women. Consistent with the reference values for sodium, these levels of chloride intake are considered to be safe and adequate for the general EU population, under the consideration that the main dietary source of chloride intake is sodium chloride. For infants aged 7-11 months, an adequate intake of 0.3 g/day is set.
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20
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He J, Qi D, Tang XM, Deng W, Deng XY, Zhao Y, Wang DX. Rosiglitazone promotes ENaC-mediated alveolar fluid clearance in acute lung injury through the PPARγ/SGK1 signaling pathway. Cell Mol Biol Lett 2019; 24:35. [PMID: 31160894 PMCID: PMC6540532 DOI: 10.1186/s11658-019-0154-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 04/29/2019] [Indexed: 02/06/2023] Open
Abstract
Background Pulmonary edema is one of the pathological characteristics of acute respiratory distress syndrome (ARDS). The epithelial sodium channel (ENaC) is thought to be the rate-limiting factor for alveolar fluid clearance (AFC) during pulmonary edema. The peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone was shown to stimulate ENaC-mediated salt absorption in the kidney. However, its role in the lung remains unclear. Here, we investigated the role of the PPARγ agonist in the lung to find out whether it can regulate AFC during acute lung injury (ALI). We also attempted to elucidate the mechanism for this. Methods Our ALI model was established through intratracheal instillation of lipopolysaccharide (LPS) in C57BL/6 J mice. The mice were randomly divided into 4 groups of 10. The control group underwent a sham operation and received an equal quantity of saline. The three experimental groups underwent intratracheal instillation of 5 mg/kg LPS, followed by intraperitoneal injection of 4 mg/kg rosiglitazone, 4 mg/kg rosiglitazone plus 1 mg/kg GW9662, or only equal quantity of saline. The histological morphology of the lung, the levels of TNF-α and IL-1β in the bronchoalveolar lavage fluid (BALF), the level of AFC, and the expressions of αENaC and serum and glucocorticoid-induced kinase-1 (SGK1) were determined. Type 2 alveolar (AT II) cells were incubated with rosiglitazone (15 μM) with or without GW9662 (10 μM). The expressions of αENaC and SGK1 were determined 24 h later. Results A mouse model of ALI was successfully established. Rosiglitazone significantly ameliorated the lung injury, decreasing the TNF-α and IL-1β levels in the BALF, enhancing AFC, and promoting the expressions of αENaC and SGK1 in ALI mice, which were abolished by the specific PPARγ blocker GW9662. In vitro, rosiglitazone increased the expressions of αENaC and SGK1. This increase was prevented by GW9662. Conclusions Rosiglitazone ameliorated the lung injury and promoted ENaC-mediated AFC via a PPARγ/SGK1-dependent signaling pathway, alleviating pulmonary edema in a mouse model of ALI.
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Affiliation(s)
- Jing He
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
| | - Di Qi
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
| | - Xu-Mao Tang
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
| | - Wang Deng
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
| | - Xin-Yu Deng
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
| | - Yan Zhao
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
| | - Dao-Xin Wang
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing, 400010 China
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21
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Cho H, Eom Y. Potential Forensic Application of Receptor for Advanced Glycation End Products (RAGE) as a Novel Biomarker for Estimating Postmortem Interval. J Forensic Sci 2019; 64:1878-1883. [DOI: 10.1111/1556-4029.14063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 01/16/2023]
Affiliation(s)
- Hye‐Won Cho
- Department of Biomedical Laboratory Science College of Medical Sciences Soonchunhyang University Asan 31538 Republic of Korea
| | - Yong‐Bin Eom
- Department of Biomedical Laboratory Science College of Medical Sciences Soonchunhyang University Asan 31538 Republic of Korea
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22
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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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23
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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: 59] [Impact Index Per Article: 8.4] [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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24
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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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25
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Wynne BM, Zou L, Linck V, Hoover RS, Ma HP, Eaton DC. Regulation of Lung Epithelial Sodium Channels by Cytokines and Chemokines. Front Immunol 2017; 8:766. [PMID: 28791006 PMCID: PMC5524836 DOI: 10.3389/fimmu.2017.00766] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 06/16/2017] [Indexed: 12/20/2022] Open
Abstract
Acute lung injury leading to acute respiratory distress (ARDS) is a global health concern. ARDS patients have significant pulmonary inflammation leading to flooding of the pulmonary alveoli. This prevents normal gas exchange with consequent hypoxemia and causes mortality. A thin fluid layer in the alveoli is normal. The maintenance of this thin layer results from fluid movement out of the pulmonary capillaries into the alveolar interstitium driven by vascular hydrostatic pressure and then through alveolar tight junctions. This is then balanced by fluid reabsorption from the alveolar space mediated by transepithelial salt and water transport through alveolar cells. Reabsorption is a two-step process: first, sodium enters via sodium-permeable channels in the apical membranes of alveolar type 1 and 2 cells followed by active extrusion of sodium into the interstitium by the basolateral Na+, K+-ATPase. Anions follow the cationic charge gradient and water follows the salt-induced osmotic gradient. The proximate cause of alveolar flooding is the result of a failure to reabsorb sufficient salt and water or a failure of the tight junctions to prevent excessive movement of fluid from the interstitium to alveolar lumen. Cytokine- and chemokine-induced inflammation can have a particularly profound effect on lung sodium transport since they can alter both ion channel and barrier function. Cytokines and chemokines affect alveolar amiloride-sensitive epithelial sodium channels (ENaCs), which play a crucial role in sodium transport and fluid reabsorption in the lung. This review discusses the regulation of ENaC via local and systemic cytokines during inflammatory disease and the effect on lung fluid balance.
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Affiliation(s)
- Brandi M Wynne
- Department of Medicine, Nephrology, Emory University, Atlanta, GA, United States.,Department of Physiology, Emory University, Atlanta, GA, United States.,The Center for Cell and Molecular Signaling, Emory University, Atlanta, GA, United States
| | - Li Zou
- Department of Physiology, Emory University, Atlanta, GA, United States
| | - Valerie Linck
- Department of Physiology, Emory University, Atlanta, GA, United States
| | - Robert S Hoover
- Department of Medicine, Nephrology, Emory University, Atlanta, GA, United States.,Department of Physiology, Emory University, Atlanta, GA, United States.,Research Service, Atlanta Veteran's Administration Medical Center, Decatur, GA, United States
| | - He-Ping Ma
- Department of Physiology, Emory University, Atlanta, GA, United States.,The Center for Cell and Molecular Signaling, Emory University, Atlanta, GA, United States
| | - Douglas C Eaton
- Department of Physiology, Emory University, Atlanta, GA, United States.,The Center for Cell and Molecular Signaling, Emory University, Atlanta, GA, United States
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26
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Flodby P, Kim YH, Beard LL, Gao D, Ji Y, Kage H, Liebler JM, Minoo P, Kim KJ, Borok Z, Crandall ED. Knockout Mice Reveal a Major Role for Alveolar Epithelial Type I Cells in Alveolar Fluid Clearance. Am J Respir Cell Mol Biol 2017; 55:395-406. [PMID: 27064541 DOI: 10.1165/rcmb.2016-0005oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Active ion transport by basolateral Na-K-ATPase (Na pump) creates an Na(+) gradient that drives fluid absorption across lung alveolar epithelium. The α1 and β1 subunits are the most highly expressed Na pump subunits in alveolar epithelial cells (AEC). The specific contribution of the β1 subunit and the relative contributions of alveolar epithelial type II (AT2) versus type I (AT1) cells to alveolar fluid clearance (AFC) were investigated using two cell type-specific mouse knockout lines in which the β1 subunit was knocked out in either AT1 cells or both AT1 and AT2 cells. AFC was markedly decreased in both knockout lines, revealing, we believe for the first time, that AT1 cells play a major role in AFC and providing insights into AEC-specific roles in alveolar homeostasis. AEC monolayers derived from knockout mice demonstrated decreased short-circuit current and active Na(+) absorption, consistent with in vivo observations. Neither hyperoxia nor ventilator-induced lung injury increased wet-to-dry lung weight ratios in knockout lungs relative to control lungs. Knockout mice showed increases in Na pump β3 subunit expression and β2-adrenergic receptor expression. These results demonstrate a crucial role for the Na pump β1 subunit in alveolar ion and fluid transport and indicate that both AT1 and AT2 cells make major contributions to these processes and to AFC. Furthermore, they support the feasibility of a general approach to altering alveolar epithelial function in a cell-specific manner that allows direct insights into AT1 versus AT2 cell-specific roles in the lung.
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Affiliation(s)
- Per Flodby
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Yong Ho Kim
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - LaMonta L Beard
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Danping Gao
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Yanbin Ji
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Hidenori Kage
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Janice M Liebler
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Parviz Minoo
- 2 Division of Neonatology, Department of Pediatrics, and
| | - Kwang-Jin Kim
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine.,3 Departments of Physiology and Biophysics.,4 Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy; and.,5 Department of Biomedical Engineering, and
| | - Zea Borok
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine.,6 Biochemistry and Molecular Biology, and
| | - Edward D Crandall
- 1 Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine.,7 Pathology, Keck School of Medicine.,8 Mork Family Department of Chemical Engineering and Materials Science, Viterbi School of Engineering, University of Southern California, Los Angeles, California
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27
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Najrana T, Ramos LM, Abu Eid R, Sanchez-Esteban J. Oligohydramnios compromises lung cells size and interferes with epithelial-endothelial development. Pediatr Pulmonol 2017; 52:746-756. [PMID: 28152278 DOI: 10.1002/ppul.23662] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 12/01/2016] [Accepted: 12/14/2016] [Indexed: 11/05/2022]
Abstract
BACKGROUND AND OBJECTIVE Severe oligohydramnios can induce pulmonary hypoplasia. However, the mechanisms by which leaking of fluids cause lung hypoplasia are not well defined. The objective of this study was to characterize a mouse model of pulmonary hypoplasia induced by oligohydramnios. METHODS Amniotic sacs were punctured on E14.5 of gestation. Untouched fetuses were used as control. Pregnancy was allowed to continue until E18.5 in which lung tissue was collected and evaluated for morphometry, proliferation, differentiation, apoptosis, and angiogenesis. RESULTS Our results found that lung weight, lung to total body weight ratio, and lung water content were reduced in oligohydramnios when compared to controls. In contrast, oligohydramnios did not affect the DNA content. Morphometric studies confirmed that oligohydramnios fetuses had smaller air spaces than control. Interestingly, cells from oligohydramnios fetuses have smaller size and less regular shapes. Oligohydramnios decreased the differentiation of type I epithelial cells and compromised apoptosis and angiogenesis while proliferation was not affected. CONCLUSIONS Although, the smaller size of the lung could be explained by a decreased of lung fluids, our data suggest that increased of external compression secondary to severe oligohydramnios can compromise cell size and interfere with epithelial and endothelial development. Type I epithelial cells could have an unrecognized key role in the differentiation of the distal lung mediated by mechanical signals. Pediatr Pulmonol. 2017;52:746-756. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Tanbir Najrana
- Department of Pediatrics, Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, 101 Dudley Street, Providence 02905, Rhode Island
| | - Lauren M Ramos
- Department of Pediatrics, Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, 101 Dudley Street, Providence 02905, Rhode Island
| | - Rasha Abu Eid
- Dental School, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Juan Sanchez-Esteban
- Department of Pediatrics, Alpert Medical School of Brown University, Women & Infants Hospital of Rhode Island, 101 Dudley Street, Providence 02905, Rhode Island
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28
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Weidenfeld S, Kuebler WM. Cytokine-Regulation of Na +-K +-Cl - Cotransporter 1 and Cystic Fibrosis Transmembrane Conductance Regulator-Potential Role in Pulmonary Inflammation and Edema Formation. Front Immunol 2017; 8:393. [PMID: 28439270 PMCID: PMC5383711 DOI: 10.3389/fimmu.2017.00393] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/21/2017] [Indexed: 12/20/2022] Open
Abstract
Pulmonary edema, a major complication of lung injury and inflammation, is defined as accumulation of extravascular fluid in the lungs leading to impaired diffusion of respiratory gases. Lung fluid balance across the alveolar epithelial barrier protects the distal airspace from excess fluid accumulation and is mainly regulated by active sodium transport and Cl- absorption. Increased hydrostatic pressure as seen in cardiogenic edema or increased vascular permeability as present in inflammatory lung diseases such as the acute respiratory distress syndrome (ARDS) causes a reversal of transepithelial fluid transport resulting in the formation of pulmonary edema. The basolateral expressed Na+-K+-2Cl- cotransporter 1 (NKCC1) and the apical Cl- channel cystic fibrosis transmembrane conductance regulator (CFTR) are considered to be critically involved in the pathogenesis of pulmonary edema and have also been implicated in the inflammatory response in ARDS. Expression and function of both NKCC1 and CFTR can be modulated by released cytokines; however, the relevance of this modulation in the context of ARDS and pulmonary edema is so far unclear. Here, we review the existing literature on the regulation of NKCC1 and CFTR by cytokines, and-based on the known involvement of NKCC1 and CFTR in lung edema and inflammation-speculate on the role of cytokine-dependent NKCC1/CFTR regulation for the pathogenesis and potential treatment of pulmonary inflammation and edema formation.
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Affiliation(s)
- Sarah Weidenfeld
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada.,Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Wolfgang M Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada.,Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Department of Surgery and Physiology, University of Toronto, Toronto, ON, Canada
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29
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Trac PT, Thai TL, Linck V, Zou L, Greenlee M, Yue Q, Al-Khalili O, Alli AA, Eaton AF, Eaton DC. Alveolar nonselective channels are ASIC1a/α-ENaC channels and contribute to AFC. Am J Physiol Lung Cell Mol Physiol 2017; 312:L797-L811. [PMID: 28283476 DOI: 10.1152/ajplung.00379.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 12/13/2022] Open
Abstract
A thin fluid layer in alveoli is normal and results from a balance of fluid entry and fluid uptake by transepithelial salt and water reabsorption. Conventional wisdom suggests the reabsorption is via epithelial Na+ channels (ENaC), but if all Na+ reabsorption were via ENaC, then amiloride, an ENaC inhibitor, should block alveolar fluid clearance (AFC). However, amiloride blocks only half of AFC. The reason for failure to block is clear from single-channel measurements from alveolar epithelial cells: ENaC channels are observed, but another channel is present at the same frequency that is nonselective for Na+ over K+, has a larger conductance, and has shorter open and closed times. These two channel types are known as highly selective channels (HSC) and nonselective cation channels (NSC). HSC channels are made up of three ENaC subunits since knocking down any of the subunits reduces HSC number. NSC channels contain α-ENaC since knocking down α-ENaC reduces the number of NSC (knocking down β- or γ-ENaC has no effect on NSC, but the molecular composition of NSC channels remains unclear). We show that NSC channels consist of at least one α-ENaC and one or more acid-sensing ion channel 1a (ASIC1a) proteins. Knocking down either α-ENaC or ASIC1a reduces both NSC and HSC number, and no NSC channels are observable in single-channel patches on lung slices from ASIC1a knockout mice. AFC is reduced in knockout mice, and wet wt-to-dry wt ratio is increased, but the percentage increase in wet wt-to-dry wt ratio is larger than expected based on the reduction in AFC.
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Affiliation(s)
- Phi T Trac
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Tiffany L Thai
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Valerie Linck
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Li Zou
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Megan Greenlee
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Qiang Yue
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Otor Al-Khalili
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Amity F Eaton
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Douglas C Eaton
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
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30
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Involvement of the Bufadienolides in the Detection and Therapy of the Acute Respiratory Distress Syndrome. Lung 2017; 195:323-332. [PMID: 28260175 DOI: 10.1007/s00408-017-9989-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/20/2017] [Indexed: 12/12/2022]
Abstract
PURPOSE The acute respiratory distress syndrome (ARDS) represents a major challenge for clinicians as well as basic scientists. The mortality rate for ARDS has been maintained within the range of 40-52%. The authors have examined the involvement of the "cardiotonic steroids" in the pathogenesis and therapy of ARDS. We have studied the possible role of the bufadienolide, marinobufagenin (MBG), in the pathogenesis of ARDS in both a rat model of ARDS and in patients afflicted with that disorder. In addition, the potential therapeutic benefit of an antagonist of MBG, resibufogenin (RBG), in an animal model has been evaluated. METHOD A syndrome resembling human ARDS was produced in the rat by exposing the animals to 100% oxygen for 48 h. In other animals, RBG was administered to these "hyperoxic" rats, and the serum MBG was measured. In human ICU patients, urinary samples were examined for levels of MBG, and the values were compared to those obtained from other ICU patients admitted with diagnoses other than ARDS. RESULTS (1) Exposure of rats to hyperoxia produced a histologic picture which resembled that of human ARDS. (2) Serum levels of MBG in the "hyperoxic" rats substantially exceeded those obtained in animals exposed to ambient oxygen levels and were reduced to normal by RBG. (3) In ARDS patients, substantial elevations in urinary MBG were obtained compared to those in non-ARDS ICU patients. CONCLUSIONS MBG may serve as an important biomarker for the development of ARDS, and RBG may represent a preventative/therapy in this disorder.
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31
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Pires-Neto RC, Del Carlo Bernardi F, Alves de Araujo P, Mauad T, Dolhnikoff M. The Expression of Water and Ion Channels in Diffuse Alveolar Damage Is Not Dependent on DAD Etiology. PLoS One 2016; 11:e0166184. [PMID: 27835672 PMCID: PMC5106024 DOI: 10.1371/journal.pone.0166184] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/24/2016] [Indexed: 12/23/2022] Open
Abstract
INTRODUCTION Aquaporins and ion channels are membrane proteins that facilitate the rapid movement of water and solutes across biological membranes. Experimental and in vitro studies reported that the function of these channels and pulmonary edema resolution are impaired in acute lung injury (ALI). Although current evidence indicates that alveolar fluid clearance is impaired in patients with ALI/diffuse alveolar damage (DAD), few human studies have addressed the alterations in pulmonary channels in this clinical condition. Additionally, it is not known whether the primary cause of DAD is a relevant variable for the channel dysfunction. METHODS Autopsied lungs of 43 patients with acute respiratory failure (ARF) due to DAD of three different etiologies, non-pulmonary sepsis, H1N1 viral infection and leptospirosis, were compared to 18 normal lungs. We quantified the expression of aquaporin (AQP) 1, AQP3, AQP5, epithelial Na+ channel (ENaC) and sodium potassium ATPase (Na-K-ATPase) in the alveolar septum using immunohistochemistry and image analysis. RESULTS The DAD group presented with increased expression of AQP3, AQP5 and Na-K-ATPase and decreased expression of ENaC compared to controls. However, there was no difference in protein expression within the DAD groups of different etiologies. CONCLUSION Water and ion channels are altered in patients with ARF due to DAD. The cause of DAD does not seem to influence the level of impairment of these channels.
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Affiliation(s)
- Ruy Camargo Pires-Neto
- Departamento de Patologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Priscila Alves de Araujo
- Departamento de Patologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
| | - Thais Mauad
- Departamento de Patologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
| | - Marisa Dolhnikoff
- Departamento de Patologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
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32
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Taylor BJ, Snyder EM, Richert ML, Wheatley CM, Chase SC, Olson LJ, Johnson BD. Effect of β 2-adrenergic receptor stimulation on lung fluid in stable heart failure patients. J Heart Lung Transplant 2016; 36:418-426. [PMID: 27863863 DOI: 10.1016/j.healun.2016.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/05/2016] [Accepted: 09/21/2016] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND The purpose of this study was to determine: (1) whether stable heart failure patients with reduced ejection fraction (HFrEF) have elevated extravascular lung water (EVLW) when compared with healthy control subjects; and (2) the effect of acute β2-adrenergic receptor (β2AR) agonist inhalation on lung fluid balance. METHODS Twenty-two stable HFrEF patients and 18 age- and gender-matched healthy subjects were studied. Lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), pulmonary capillary blood volume (Vc) (via re-breathe) and lung tissue volume (Vtis) (via computed tomography) were assessed before and within 30 minutes after administration of nebulized albuterol. EVLW was derived as Vtis - Vc. RESULTS Before administration of albuterol, Vtis and EVLW were higher in HFrEF vs control (998 ± 200 vs 884 ± 123 ml, p = 0.041; and 943 ± 202 vs 802 ± 133 ml, p = 0.015, respectively). Albuterol decreased Vtis and EVLW in HFrEF patients (-4.6 ± 7.8%, p = 0.010; -4.6 ± 8.8%, p = 0.018) and control subjects (-2.8 ± 4.9%, p = 0.029; -3.0 ± 5.7%, p = 0.045). There was an inverse relationship between pre-albuterol values and pre- to post-albuterol change for EVLW (r2 = -0.264, p = 0.015) and DmCO (r2 = -0.343, p = 0.004) in HFrEF only. CONCLUSION Lung fluid is elevated in stable HFrEF patients relative to healthy subjects. Stimulation of β2ARs may cause fluid removal in HFrEF, especially in patients with greater evidence of increased lung water at baseline.
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Affiliation(s)
- Bryan J Taylor
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, UK; Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
| | - Eric M Snyder
- School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Maile L Richert
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Courtney M Wheatley
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Steven C Chase
- Division of Cardiovascular Diseases, Mayo Graduate School, Mayo Clinic, Rochester, Minnesota, USA
| | - Lyle J Olson
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Bruce D Johnson
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
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Deng J, Wang DX, Liang AL, Tang J, Xiang DK. Effects of baicalin on alveolar fluid clearance and α-ENaC expression in rats with LPS-induced acute lung injury. Can J Physiol Pharmacol 2016; 95:122-128. [PMID: 27992235 DOI: 10.1139/cjpp-2016-0212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Baicalin has been reported to attenuate lung edema in the process of lung injury. However, the effect of baicalin on alveolar fluid clearance (AFC) and epithelial sodium channel (ENaC) expression has not been tested. Sprague-Dawley rats were anesthetized and intratracheally injected with either 1 mg/kg lipopolysaccharide (LPS) or saline vehicle. Baicalin with various concentrations (10, 50, and 100 mg/kg) was injected intraperitoneally 30 min before administration of LPS. Then lungs were isolated for measurement of AFC, cyclic adenosine monophosphate (cAMP) level, and cellular localization of α-ENaC. Moreover, mouse alveolar type II (ATII) epithelial cell line was incubated with baicalin (30 μmol/L), adenylate cyclase inhibitor SQ22536 (10 μmol/L), or cAMP-dependent protein kinase inhibitor (PKA) KT5720 (0.3 μmol/L) 15 min before LPS (1 μg/mL) incubation. Protein expression of α-ENaC was detected by Western blot. Baicalin increased cAMP concentration and AFC in a dose-dependent manner in rats with LPS-induced acute lung injury. The increase of AFC induced by baicalin was associated with an increase in the abundance of α-ENaC protein. SQ22536 and KT5720 prevented the increase of α-ENaC expression caused by baicalin in vitro. These findings suggest that baicalin prevents LPS-induced reduction of AFC by upregulating α-ENaC protein expression, which is activated by stimulating cAMP/PKA signaling pathway.
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Affiliation(s)
- Jia Deng
- a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China
| | - Dao-Xin Wang
- b Department of Respiratory Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ai-Ling Liang
- a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China
| | - Jing Tang
- a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China
| | - Da-Kai Xiang
- a Department of Respiratory Medicine, Traditional Chinese Medical Hospital of Jiangbei District, Chongqing, China
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34
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Gottfried L, Lin X, Barravecchia M, Dean DA. Identification of an alveolar type I epithelial cell-specific DNA nuclear import sequence for gene delivery. Gene Ther 2016; 23:734-742. [PMID: 27367840 PMCID: PMC10141512 DOI: 10.1038/gt.2016.52] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/27/2016] [Accepted: 06/20/2016] [Indexed: 11/09/2022]
Abstract
The ability to restrict gene delivery and expression to particular cell types is of paramount importance for many types of gene therapy, especially in the lung. The alveolar epithelial type I (ATI) cell, in particular, is an attractive cell type to target, as it comprises 95% of the internal surface area of the lung. We demonstrate, through microinjection of fluorescently labeled plasmids, that a DNA sequence within the rat T1α promoter was able to mediate ATI cell-specific plasmid DNA nuclear import due to the binding of ATI-enriched transcription factors. Promoter deletion analysis and site-directed mutagenesis of specific transcription-factor-binding sites within the +101 to -200 bp region of the T1α promoter identified HNF3 and TTF-1 as critical transcription factors for import. To test for nuclear import in vivo, plasmids expressing GFP from the CMV promoter were delivered into the lungs of mice by electroporation and evaluated immunohistochemically 48 h later. Plasmids carrying the 1.3 kbp T1α sequence resulted in GFP expression almost exclusively in ATI cells. This represents a new and highly efficient way to target a specific lung epithelial cell type both in vitro and in vivo based on the restriction of DNA nuclear import.
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Affiliation(s)
- L Gottfried
- Department of Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - X Lin
- Department of Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - M Barravecchia
- Department of Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - D A Dean
- Department of Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
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Pharmacogenetic Effects of Inhaled Salbutamol on 10-km Time Trial Performance in Competitive Male and Female Cyclists. Clin J Sport Med 2016; 26:145-51. [PMID: 25894531 DOI: 10.1097/jsm.0000000000000201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the effects of single nucleotide polymorphisms (SNPs) in the adrenergic β2-receptor gene (ADRB2, rs1042713, and rs1042714) and epithelial Na channel gene (SCNN1A, rs2228576) on cycling performance after the inhalation of salbutamol. DESIGN Randomized double-blind, mixed-model repeated measures. SETTING University Research Setting. PARTICIPANTS Sixty-nine trained (maximal oxygen consumption: 62.3 ± 7.6 mL·kg·min) male and female cyclists, aged 19 to 40 years. INTERVENTIONS Participants performed two 10-km time trials 60 minutes after the inhalation of 400 μg of salbutamol or placebo. Subjects were genotyped for the three SNPs (rs1042713: AA 8, AG 30 GG 31; rs1042714: CC 19, CG 35, GG 15; rs2228576: GG: 31 GA: 34 AA: 4). MAIN OUTCOME MEASURES Forced expiratory volume in 1 second (FEV1) was assessed immediately before and 30 minutes after inhalation. Performance was measured by mean power output maintained over the duration of the time trial. RESULTS There was a significant increase in FEV1 after the inhalation of salbutamol [mean (SD) = 5.68% (4.7)] compared with placebo [0.84% (2.8); P < 0.001]; however, this did not lead to an improvement in 10-km cycling time trial performance. Neither the bronchodilatory response nor the time trial performance after salbutamol was affected by genotype at any of the 3 SNPs. CONCLUSIONS In cyclists, FEV1 was significantly improved after salbutamol administration regardless of genotypic variation at the ADRB2 (rs1042713 and rs1042714) and SCNN1A (rs2228576) genes. Despite this improvement in lung function, 10-km time trial performance was not altered after the inhalation of salbutamol. CLINICAL RELEVANCE Our findings did not show genotype-dependent differences in bronchodilatory responses and athletic performance to inhaled salbutamol, suggesting that genotype-specific drug therapy will not improve asthmatic athletes' care nor athletic performance.
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Yang J, Hernandez BJ, Martinez Alanis D, Narvaez del Pilar O, Vila-Ellis L, Akiyama H, Evans SE, Ostrin EJ, Chen J. The development and plasticity of alveolar type 1 cells. Development 2015; 143:54-65. [PMID: 26586225 DOI: 10.1242/dev.130005] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/11/2015] [Indexed: 12/16/2022]
Abstract
Alveolar type 1 (AT1) cells cover >95% of the gas exchange surface and are extremely thin to facilitate passive gas diffusion. The development of these highly specialized cells and its coordination with the formation of the honeycomb-like alveolar structure are poorly understood. Using new marker-based stereology and single-cell imaging methods, we show that AT1 cells in the mouse lung form expansive thin cellular extensions via a non-proliferative two-step process while retaining cellular plasticity. In the flattening step, AT1 cells undergo molecular specification and remodel cell junctions while remaining connected to their epithelial neighbors. In the folding step, AT1 cells increase in size by more than 10-fold and undergo cellular morphogenesis that matches capillary and secondary septa formation, resulting in a single AT1 cell spanning multiple alveoli. Furthermore, AT1 cells are an unexpected source of VEGFA and their normal development is required for alveolar angiogenesis. Notably, a majority of AT1 cells proliferate upon ectopic SOX2 expression and undergo stage-dependent cell fate reprogramming. These results provide evidence that AT1 cells have both structural and signaling roles in alveolar maturation and can exit their terminally differentiated non-proliferative state. Our findings suggest that AT1 cells might be a new target in the pathogenesis and treatment of lung diseases associated with premature birth.
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Affiliation(s)
- Jun Yang
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Belinda J Hernandez
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Denise Martinez Alanis
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Lisandra Vila-Ellis
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA Tecnologico de Monterrey - Escuela de Medicina, Monterrey 64710, Mexico
| | - Haruhiko Akiyama
- Department of Orthopedics, Kyoto University, Sakyo, Kyoto 606-8507, Japan
| | - Scott E Evans
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Edwin J Ostrin
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Jichao Chen
- Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA Center for Stem Cells and Developmental Biology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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Can Racemic Albuterol Help Patients With Respiratory Failure in the PICU? Pediatr Crit Care Med 2015; 16:678-9. [PMID: 26335118 DOI: 10.1097/pcc.0000000000000462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Huang B, Wang DX, Deng W. Protective effects of dexamethasone on early acute lung injury induced by oleic acid in rats. Int J Clin Exp Med 2014; 7:4698-4709. [PMID: 25663967 PMCID: PMC4307414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 11/25/2014] [Indexed: 06/04/2023]
Abstract
OBJECTIVE Whether alveolar edema could be cleared by alveolar epithelial is a key to the treatment and prognosis of ALI (acute lung injury). In this study, oleic acid(OA)-induced ALI model was established, the expression of α1 Na(+)/K(+)-ATPase (NKA) and β1 Na(+)/K(+)-ATPase were performed in vivo to investigate the mechanism of alveolar fluid clearance (AFC) in ALI and the effect of early low doses of dexamethasone on alveolar fluid clearance. METHODS In this study, Male rats were challenged by OA with or without dexamethasone (1 mg/kg, iv) post-treatment. Lung histopathology, blood gas, pulmonary vascular permeability, BALF IL-6, MPO and NKA activity of lung were examined. α1NKA and β1NKA mRNA and protein expression were detected. RESULTS The results indicated that compared with sham operated group, NKA activity, mRNA and protein expression of α1NKA and β1NKA were decreased in OA treated group, while wet/dry ratio, lung index, IL-6, and MPO activity were increased significantly. Pulmonary edema was obviously seen under light microscope. Those indexes were improved in dexamethasone treated group compared to OA treated group. CONCLUSION The expression of NKA to decline for the lung injury is one important mechanism of pulmonary edema. Early low dose of dexamethasone treatment could suppress the expression of inflammatory mediators, improved lung epithelial-endothelial barrier permeability, increased the expressions of α1 NKA and β1 NKA mRNA, α1 NKA and β1 NKA protein level, stimulated NKA activity and decreased pulmonary edema. In conclusion, these observations suggest that early low dose of dexamethasone treatment has a protective effect on OA induced ALI.
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Affiliation(s)
- Bin Huang
- Department of Critical Care Medicine, The Second Affiliated Hospital of Chongqing Medical UniversityChongqing 400010, China
| | - Dao-Xin Wang
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical UniversityChongqing 400010, China
| | - Wang Deng
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical UniversityChongqing 400010, China
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Orme IM. Vaccines to prevent tuberculosis infection rather than disease: Physiological and immunological aspects. Tuberculosis (Edinb) 2014; 101:210-216. [PMID: 25500316 DOI: 10.1016/j.tube.2014.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/02/2014] [Accepted: 10/22/2014] [Indexed: 12/11/2022]
Abstract
There is increasing enthusiasm and optimism that a vaccine could be developed that prevents infection rather than disease. In this article I discuss the fact that despite this optimism nothing has been produced so far that seems to have this capability, and moreover even the borderline between when infection ends and disease begins has not even been defined. To be effective such a vaccine, or at least the immunity it would generate, would have to work within the confines of the pulmonary physiological systems, which are complex. To date much of the emphasis here has turned away from T cell mediated immunity and towards establishing specific antibodies in the lungs. Here, I argue that with the exception of a possible exclusionary function, most claims of a protective role of antibody are completely over-blown. Finally, even if we had a potential "anti-infection" vaccine, how would we test and validate it?
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Affiliation(s)
- Ian M Orme
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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Zhao R, Liang X, Zhao M, Liu SL, Huang Y, Idell S, Li X, Ji HL. Correlation of apical fluid-regulating channel proteins with lung function in human COPD lungs. PLoS One 2014; 9:e109725. [PMID: 25329998 PMCID: PMC4201481 DOI: 10.1371/journal.pone.0109725] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/03/2014] [Indexed: 12/22/2022] Open
Abstract
Links between epithelial ion channels and chronic obstructive pulmonary diseases (COPD) are emerging through animal model and in vitro studies. However, clinical correlations between fluid-regulating channel proteins and lung function in COPD remain to be elucidated. To quantitatively measure epithelial sodium channels (ENaC), cystic fibrosis transmembrane conductance regulator (CFTR), and aquaporin 5 (AQP5) proteins in human COPD lungs and to analyze the correlation with declining lung function, quantitative western blots were used. Spearman tests were performed to identify correlations between channel proteins and lung function. The expression of α and β ENaC subunits was augmented and inversely associated with lung function. In contrast, both total and alveolar type I (ATI) and II (ATII)-specific CFTR proteins were reduced. The expression level of CFTR proteins was associated with FEV1 positively. Abundance of AQP5 proteins and extracellular superoxide dismutase (SOD3) was decreased and correlated with spirometry test results and gas exchange positively. Furthermore, these channel proteins were significantly associated with severity of disease. Our study demonstrates that expression of ENaC, AQP5, and CFTR proteins in human COPD lungs is quantitatively associated with lung function and severity of COPD. These apically located fluid-regulating channels may thereby serve as biomarkers and potent druggable targets of COPD.
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Affiliation(s)
- Runzhen Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Xinrong Liang
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Meimi Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Shan-Lu Liu
- Department of Molecular Microbiology and Immunology, Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Yao Huang
- Department of Obstetrics and Gynecology, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, United States of America
| | - Steven Idell
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- Medicine, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Xiumin Li
- Xinxiang Medical University, Xinxiang, Henan, China
| | - Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- * E-mail:
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Matthay MA. Resolution of pulmonary edema. Thirty years of progress. Am J Respir Crit Care Med 2014; 189:1301-8. [PMID: 24881936 DOI: 10.1164/rccm.201403-0535oe] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
In the last 30 years, we have learned much about the molecular, cellular, and physiological mechanisms that regulate the resolution of pulmonary edema in both the normal and the injured lung. Although the physiological mechanisms responsible for the formation of pulmonary edema were identified by 1980, the mechanisms that explain the resolution of pulmonary edema were not well understood at that time. However, in the 1980s several investigators provided novel evidence that the primary mechanism for removal of alveolar edema fluid depended on active ion transport across the alveolar epithelium. Sodium enters through apical channels, primarily the epithelial sodium channel, and is pumped into the lung interstitium by basolaterally located Na/K-ATPase, thus creating a local osmotic gradient to reabsorb the water fraction of the edema fluid from the airspaces of the lungs. The resolution of alveolar edema across the normally tight epithelial barrier can be up-regulated by cyclic adenosine monophosphate (cAMP)-dependent mechanisms through adrenergic or dopamine receptor stimulation, and by several cAMP-independent mechanisms, including glucocorticoids, thyroid hormone, dopamine, and growth factors. Whereas resolution of alveolar edema in cardiogenic pulmonary edema can be rapid, the rate of edema resolution in most patients with acute respiratory distress syndrome (ARDS) is markedly impaired, a finding that correlates with higher mortality. Several mechanisms impair the resolution of alveolar edema in ARDS, including cell injury from unfavorable ventilator strategies or pathogens, hypoxia, cytokines, and oxidative stress. In patients with severe ARDS, alveolar epithelial cell death is a major mechanism that prevents the resolution of lung edema.
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Affiliation(s)
- Michael A Matthay
- Departments of Medicine and Anesthesia and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California
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Johansson HM, Newman DR, Sannes PL. Whole-genome analysis of temporal gene expression during early transdifferentiation of human lung alveolar epithelial type 2 cells in vitro. PLoS One 2014; 9:e93413. [PMID: 24690998 PMCID: PMC3972118 DOI: 10.1371/journal.pone.0093413] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 03/05/2014] [Indexed: 12/21/2022] Open
Abstract
It is generally accepted that the surfactant-producing pulmonary alveolar epithelial type II (AT2) cell acts as the progenitor of the type I (AT1) cell, but the regulatory mechanisms involved in this relationship remain the subject of active investigation. While previous studies have established a number of specific markers that are expressed during transdifferentiation from AT2 to AT1 cells, we hypothesized that additional, previously unrecognized, signaling pathways and relevant cellular functions are transcriptionally regulated at early stages of AT2 transition. In this study, a discovery-based gene expression profile analysis was undertaken of freshly isolated human AT2 (hAT2) cells grown on extracellular matrix (ECM) substrata known to either support (type I collagen) or retard (Matrigel) the early transdifferentiation process into hAT1-like cells over the first three days. Cell type-specific expression patterns analyzed by Illumina Human HT-12 BeadChip yielded over 300 genes that were up- or down-regulated. Candidate genes significantly induced or down-regulated during hAT2 transition to hAT1-like cells compared to non-transitioning hAT2 cells were identified. Major functional groups were also recognized, including those of signaling and cytoskeletal proteins as well as genes of unknown function. Expression of established signatures of hAT2 and hAT1 cells, such as surfactant proteins, caveolin-1, and channels and transporters, was confirmed. Selected novel genes further validated by qRT-PCR, protein expression analysis, and/or cellular localization included SPOCK2, PLEKHO1, SPRED1, RAB11FIP1, PTRF/CAVIN-1 and RAP1GAP. These results further demonstrate the utility of genome-wide analysis to identify relevant, novel cell type-specific signatures of early ECM-regulated alveolar epithelial transdifferentiation processes in vitro.
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Affiliation(s)
- Helena Morales Johansson
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Donna R. Newman
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Philip L. Sannes
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
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Rozycki HJ. Potential contribution of type I alveolar epithelial cells to chronic neonatal lung disease. Front Pediatr 2014; 2:45. [PMID: 24904906 PMCID: PMC4032902 DOI: 10.3389/fped.2014.00045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 05/05/2014] [Indexed: 12/16/2022] Open
Abstract
The alveolar surface is covered by large flat Type I cells (alveolar epithelial cells 1, AEC1). The normal physiological function of AEC1s involves gas exchange, based on their location in approximation to the capillary endothelium and their thinness, and in ion and water flux, as shown by the presence of solute active transport proteins, water channels, and impermeable tight junctions between cells. With the recent ability to produce relatively pure cultures of AEC1 cells, new functions have been described. These may be relevant to lung injury, repair, and the abnormal development that characterizes bronchopulmonary dysplasia (BPD). To hypothesize a potential role for AEC1 in the development of lung injury and abnormal repair/development in premature lungs, evidence is presented for their presence in the developing lung, how their source may not be the Type II cell (AEC2) as has been assumed for 40 years, and how the cell can be damaged by same type of stressors as those which lead to BPD. Recent work shows that the cells are part of the innate immune response, capable of producing pro-inflammatory mediators, which could contribute to the increase in inflammation seen in early BPD. One of the receptors found exclusively on AEC1 cells in the lung, called RAGE, may also have a role in increased inflammation and alveolar simplification. While the current evidence for AEC1 involvement in BPD is circumstantial and limited at present, the accumulating data supports several hypotheses and questions regarding potential differences in the behavior of AEC1 cells from newborn and premature lung compared with the adult lung.
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Affiliation(s)
- Henry J Rozycki
- Division of Neonatal Medicine, Children's Hospital of Richmond at Virginia Commonwealth University , Richmond, VA , USA
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Downs CA, Kreiner LH, Trac DQ, Helms MN. Acute effects of cigarette smoke extract on alveolar epithelial sodium channel activity and lung fluid clearance. Am J Respir Cell Mol Biol 2013; 49:251-9. [PMID: 23526224 DOI: 10.1165/rcmb.2012-0234oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cigarette smoke contains high levels of reactive species. Moreover, cigarette smoke can induce cellular production of oxidants. The purpose of this study was to determine the effect of cigarette smoke extract (CSE)-derived oxidants on epithelial sodium channel (ENaC) activity in alveolar type 1 (T1) and type 2 (T2) cells and to measure corresponding rates of fluid clearance in mice receiving a tracheal instillation of CSE. Single-channel patch clamp analysis of T1 and T2 cells demonstrate that CSE exposure increases ENaC activity (NPo), measured as the product of the number of channels (N) and a channels open probability (Po), from 0.17 ± 0.07 to 0.34 ± 0.10 (n = 9; P = 0.04) in T1 cells. In T2 cells, CSE increased NPo from 0.08 ± 0.03 to 0.35 ± 0.10 (n = 9; P = 0.02). In both cell types, addition of tetramethylpiperidine and glutathione attenuated CSE-induced increases in ENaC NPo. Biotinylation and cycloheximide chase assays indicate that CSE-derived ROS increases channel activity, in part, by maintaining cell surface expression of the α-ENaC subunit. In vivo studies show that tracheal instillation of CSE promoted alveolar fluid clearance after 105 minutes compared with vehicle control (n = 10/group; P < 0.05).
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Affiliation(s)
- Charles A Downs
- Nell Hodgson Woodruff School of Nursing, School of Medicine, Emory University, Atlanta, GA 30322, USA
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Shabbir W, Scherbaum-Hazemi P, Tzotzos S, Fischer B, Fischer H, Pietschmann H, Lucas R, Lemmens-Gruber R. Mechanism of action of novel lung edema therapeutic AP301 by activation of the epithelial sodium channel. Mol Pharmacol 2013; 84:899-910. [PMID: 24077967 DOI: 10.1124/mol.113.089409] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AP301 [Cyclo(CGQRETPEGAEAKPWYC)], a cyclic peptide comprising the human tumor necrosis factor lectin-like domain (TIP domain) sequence, is currently being developed as a treatment for lung edema and has been shown to reduce extravascular lung water and improve lung function in mouse, rat, and pig models. The current paradigm for liquid homeostasis in the adult mammalian lung is that passive apical uptake of sodium via the amiloride-sensitive epithelial Na⁺ channel (ENaC) and nonselective cyclic-nucleotide-gated cation channels creates the major driving force for reabsorption of water through the alveolar epithelium in addition to other ion channels such as potassium and chloride channels. AP301 can increase amiloride-sensitive current in A549 cells as well as in freshly isolated type II alveolar epithelial cells from different species. ENaC is expressed endogenously in all of these cell types. Consequently, this study was undertaken to determine whether ENaC is the specific target of AP301. The effect of AP301 in A549 cells as well as in human embryonic kidney cells and Chinese hamster ovary cells heterologously expressing human ENaC subunits (α, β, γ, and δ) was measured in patch clamp experiments. The congener TIP peptide AP318 [Cyclo(4-aminobutanoic acid-GQRETPEGAEAKPWYD)] activated ENaC by increasing single-channel open probability. AP301 increased current in proteolytically activated (cleaved) but not near-silent (uncleaved) ENaC in a reversible manner. αβγ- or δβγ-ENaC coexpression was required for maximal activity. No increase in current was observed after deglycosylation of extracellular domains of ENaC. Thus, our data suggest that the specific interaction of AP301 with both endogenously and heterologously expressed ENaC requires precedent binding to glycosylated extracellular loop(s).
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Affiliation(s)
- Waheed Shabbir
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (W.S., P.S.-H., R.L.-G.); APEPTICO Forschung und Entwicklung GmbH, Vienna, Austria (S.T., B.F., H.F., H.P.); and Division of Pulmonary Medicine, Department of Pharmacology and Toxicology, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia (R.L.)
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Abstract
Ion channels perform a variety of cellular functions in lung epithelia. Oxidant- and antioxidant-mediated mechanisms (that is, redox regulation) of ion channels are areas of intense research. Significant progress has been made in our understanding of redox regulation of ion channels since the last Experimental Biology report in 2003. Advancements include: 1) identification of nonphagocytic NADPH oxidases as sources of regulated reactive species (RS) production in epithelia, 2) an understanding that excessive treatment with antioxidants can result in greater oxidative stress, and 3) characterization of novel RS signaling pathways that converge upon ion channel regulation. These advancements, as discussed at the 2013 Experimental Biology Meeting in Boston, MA, impact our understanding of oxidative stress in the lung, and, in particular, illustrate that the redox state has profound effects on ion channel and cellular function.
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De Brito T, Aiello VD, da Silva LFF, Gonçalves da Silva AM, Ferreira da Silva WL, Castelli JB, Seguro AC. Human hemorrhagic pulmonary leptospirosis: pathological findings and pathophysiological correlations. PLoS One 2013; 8:e71743. [PMID: 23951234 PMCID: PMC3741125 DOI: 10.1371/journal.pone.0071743] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 06/26/2013] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Leptospirosis is a re-emerging zoonosis with protean clinical manifestations. Recently, the importance of pulmonary hemorrhage as a lethal complication of this disease has been recognized. In the present study, five human necropsies of leptospirosis (Weil's syndrome) with extensive pulmonary manifestations were analysed, and the antibodies expressed in blood vessels and cells involved in ion and water transport were used, seeking to better understand the pathophysiology of the lung injury associated with this disease. PRINCIPAL FINDINGS Prominent vascular damage was present in the lung microcirculation, with decreased CD34 and preserved aquaporin 1 expression. At the periphery and even inside the extensive areas of edema and intraalveolar hemorrhage, enlarged, apparently hypertrophic type I pneumocytes (PI) were detected and interpreted as a non-specific attempt of clearence of the intraalveolar fluid, in which ionic transport, particularly of sodium, plays a predominant role, as suggested by the apparently increased ENaC and aquaporin 5 expression. Connexin 43 was present in most pneumocytes, and in the cytoplasm of the more preserved endothelial cells. The number of type II pneumocytes (PII) was slightly decreased when compared to normal lungs and those of patients with septicemia from other causes, a fact that may contribute to the progressively low PI count, resulting in deficient restoration after damage to the alveolar epithelial integrity and, consequently, a poor outcome of the pulmonary edema and hemorrhage. CONCLUSIONS Pathogenesis of lung injury in human leptospirosis was discussed, and the possibility of primary non-inflammatory vascular damage was considered, so far of undefinite etiopathogenesis, as the initial pathological manifestation of the disease.
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Affiliation(s)
- Thales De Brito
- Institute of Tropical Medicine, São Paulo University Medical School, São Paulo, Brazil.
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Contribution of CFTR to alveolar fluid clearance by lipoxin A4 via PI3K/Akt pathway in LPS-induced acute lung injury. Mediators Inflamm 2013; 2013:862628. [PMID: 23766562 PMCID: PMC3671557 DOI: 10.1155/2013/862628] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 04/07/2013] [Accepted: 04/18/2013] [Indexed: 01/11/2023] Open
Abstract
The lipoxins are the first proresolution mediators to be recognized and described as the endogenous “braking signals” for inflammation. We evaluated the anti-inflammatory and proresolution bioactions of lipoxin A4 in our lipopolysaccharide (LPS-)induced lung injury model. We demonstrated that lipoxin A4 significantly improved histology of rat lungs and inhibited IL-6 and TNF-α in LPS-induced lung injury. In addition, lipoxin A4 increased alveolar fluid clearance (AFC) and the effect of lipoxin A4 on AFC was abolished by CFTRinh-172 (a specific inhibitor of CFTR). Moreover, lipoxin A4 could increase cystic fibrosis transmembrane conductance regulator (CFTR) protein expression in vitro and in vivo. In rat primary alveolar type II (ATII) cells, LPS decreased CFTR protein expression via activation of PI3K/Akt, and lipoxin A4 suppressed LPS-stimulated phosphorylation of Akt. These results showed that lipoxin A4 enhanced CFTR protein expression and increased AFC via PI3K/Akt pathway. Thus, lipoxin A4 may provide a potential therapeutic approach for acute lung injury.
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Chloride transport-driven alveolar fluid secretion is a major contributor to cardiogenic lung edema. Proc Natl Acad Sci U S A 2013; 110:E2308-16. [PMID: 23645634 DOI: 10.1073/pnas.1216382110] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Alveolar fluid clearance driven by active epithelial Na(+) and secondary Cl(-) absorption counteracts edema formation in the intact lung. Recently, we showed that impairment of alveolar fluid clearance because of inhibition of epithelial Na(+) channels (ENaCs) promotes cardiogenic lung edema. Concomitantly, we observed a reversal of alveolar fluid clearance, suggesting that reversed transepithelial ion transport may promote lung edema by driving active alveolar fluid secretion. We, therefore, hypothesized that alveolar ion and fluid secretion may constitute a pathomechanism in lung edema and aimed to identify underlying molecular pathways. In isolated perfused lungs, alveolar fluid clearance and secretion were determined by a double-indicator dilution technique. Transepithelial Cl(-) secretion and alveolar Cl(-) influx were quantified by radionuclide tracing and alveolar Cl(-) imaging, respectively. Elevated hydrostatic pressure induced ouabain-sensitive alveolar fluid secretion that coincided with transepithelial Cl(-) secretion and alveolar Cl(-) influx. Inhibition of either cystic fibrosis transmembrane conductance regulator (CFTR) or Na(+)-K(+)-Cl(-) cotransporters (NKCC) blocked alveolar fluid secretion, and lungs of CFTR(-/-) mice were protected from hydrostatic edema. Inhibition of ENaC by amiloride reproduced alveolar fluid and Cl(-) secretion that were again CFTR-, NKCC-, and Na(+)-K(+)-ATPase-dependent. Our findings show a reversal of transepithelial Cl(-) and fluid flux from absorptive to secretory mode at hydrostatic stress. Alveolar Cl(-) and fluid secretion are triggered by ENaC inhibition and mediated by NKCC and CFTR. Our results characterize an innovative mechanism of cardiogenic edema formation and identify NKCC1 as a unique therapeutic target in cardiogenic lung edema.
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The effect of endogenous angiotensin II on alveolar fluid clearance in rats with acute lung injury. Can Respir J 2013; 19:311-8. [PMID: 23061076 DOI: 10.1155/2012/951025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND In acute lung injury (ALI), angiotensin II (Ang II) plays a vital role in the stimulation of pulmonary permeability edema formation through the angiotensin type 1 (AT1) receptor. The effect of Ang II on alveolar fluid clearance (AFC) in ALI remains unknown. METHODS Sprague Dawley rats were anesthetized and intratracheally injected with 1 mg⁄kg lipopolysaccharide (LPS), while control rats received saline. The AT1 receptor antagonist ZD7155 was injected intraperitoneally (10 mg⁄kg) 30 min before LPS administration. The lungs were isolated for AFC measurement, and alpha-epithelial sodium channel (ENaC) messenger RNA and protein expression were detected by reverse-transcription polymerase chain reaction and Western blot. RESULTS LPS-induced ALI caused an increase in Ang II levels in plasma and lung tissue but a decrease in AFC. The time course of Ang II levels paralleled that of AFC. Pretreatment with ZD7155 prevented ALI-induced reduction of AFC. ZD7155 also reversed the ALI-induced reduction of beta-ENaC and gamma-ENaC levels, and further decreased alpha-ENaC levels. CONCLUSIONS These findings suggest that endogenous Ang II inhibits AFC and dysregulates ENaC expression via AT1 receptors, which contribute to alveolar filling and pulmonary edema in LPS-induced ALI.
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