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Varedi M, Pajouhi N, Owji M, Naghibalhossaini F, Omrani GHR. Differential modulation of claudin 4 expression and myosin light chain phosphorylation by thyroid function in lung injury. CLINICAL RESPIRATORY JOURNAL 2015; 11:797-804. [PMID: 26619308 DOI: 10.1111/crj.12418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 09/27/2015] [Accepted: 11/13/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Trauma and ventilator-induced lung injury is often associated with endothelial-epithelial barriers breakdown, which may lead to multiple system organ failure (MSOF) and death in critically ill patients. Although molecular mechanism involved in MSOF is not known, junctional opening is believed to happen. In vitro, thyroid hormones inhibit myosin light chain (MLC) phosphorylation and may, thus, inhibit cellular contraction and junctional opening. Trauma is also associated with tissue hypo-thyroid state. Therefore, we examined the effects of thyroid function on expression of phospho-MLC (pp-MLC) and claudin 4 (Clud4), key proteins involved in regulation of junctional tightness, in lung injury. METHODS Rats were rendered hypo-thyroid (Hypo) or hyperthyroid (Hyper) by adding methimazole or levo-thyroxine, respectively, to their drinking water. Untreated euthyroid (Eue) animals were used as control. Lung pp-MLC and Clud4 proteins were assessed by western blotting and in situ immunodetection, respectively. Lung injury was induced by high tidal volume mechanical ventilation. RESULTS Lung injury was significantly enhanced in Hypo animals and attenuated in Hyper animals. Parallel changes in expression of lung pp-MLC were detected. Alterations in lung histomorphology correlated with the level of pp-MLC. Expression of alveolar and bronchiolar Clud4 protein was differentially affected by the state of thyroid gland. CONCLUSIONS Our data suggest that thyroid function plays significant role in lung injury perhaps by modulating expression of the proteins involved in junctional tightness. Besides, they strongly support the idea that the tissue hypo-thyroid state may contribute to endothelial-epithelial barriers breakdown associated with trauma.
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Affiliation(s)
- Masoumeh Varedi
- Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Naser Pajouhi
- Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Owji
- Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Gholam H R Omrani
- Department of Internal Medicine and Endocrine/Metabolism Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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Ho MSH, Mei SHJ, Stewart DJ. The Immunomodulatory and Therapeutic Effects of Mesenchymal Stromal Cells for Acute Lung Injury and Sepsis. J Cell Physiol 2015; 230:2606-17. [PMID: 25913273 DOI: 10.1002/jcp.25028] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 04/21/2015] [Indexed: 12/20/2022]
Abstract
It is increasingly recognized that immunomodulation represents an important mechanism underlying the benefits of many stem cell therapies, rather than the classical paradigm of transdifferentiation and cell replacement. In the former paradigm, the beneficial effects of cell therapy result from paracrine mechanism(s) and/or cell-cell interaction as opposed to direct engraftment and repair of diseased tissue and/or dysfunctional organs. Depending on the cell type used, components of the secretome, including microRNA (miRNA) and extracellular vesicles, may be able to either activate or suppress the immune system even without direct immune cell contact. Mesenchymal stromal cells (MSCs), also referred to as mesenchymal stem cells, are found not only in the bone marrow, but also in a wide variety of organs and tissues. In addition to any direct stem cell activities, MSCs were the first stem cells recognized to modulate immune response, and therefore they will be the focus of this review. Specifically, MSCs appear to be able to effectively attenuate acute and protracted inflammation via interactions with components of both innate and adaptive immune systems. To date, this capacity has been exploited in a large number of preclinical studies and MSC immunomodulatory therapy has been attempted with various degrees of success in a relatively large number of clinical trials. Here, we will explore the various mechanism employed by MSCs to effect immunosuppression as well as review the current status of its use to treat excessive inflammation in the context of acute lung injury (ALI) and sepsis in both preclinical and clinical settings.
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Affiliation(s)
- Mirabelle S H Ho
- Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario
| | - Shirley H J Mei
- Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario
| | - Duncan J Stewart
- Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario
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Breakdown of Epithelial Barrier Integrity and Overdrive Activation of Alveolar Epithelial Cells in the Pathogenesis of Acute Respiratory Distress Syndrome and Lung Fibrosis. BIOMED RESEARCH INTERNATIONAL 2015; 2015:573210. [PMID: 26523279 PMCID: PMC4615219 DOI: 10.1155/2015/573210] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/05/2015] [Accepted: 09/15/2015] [Indexed: 12/29/2022]
Abstract
Individual alveolar epithelial cells (AECs) collaboratively form a tight barrier between atmosphere and fluid-filled tissue to enable normal gas exchange. The tight junctions of AECs provide intercellular sealing and are integral to the maintenance of the AEC barrier integrity. Disruption and failure of reconstitution of AEC barrier result in catastrophic consequences, leading to alveolar flooding and subsequent devastating fibrotic scarring. Recent evidences reveal that many of the fibrotic lung diseases involve AECs both as a frequent target of injury and as a driver of ongoing pathological processes. Aberrantly activated AECs express most of the growth factors and chemokines responsible for the proliferation, migration, and activation of fibroblasts. Current evidences suggest that AECs may acquire overdrive activation in the initial step of fibrosis by several mechanisms, including abnormal recapitulation of the developmental pathway, defects of the molecules essential for epithelial integrity, and acceleration of aging-related properties. Among these initial triggering events, epithelial Pten, a multiple phosphatase that negatively regulates the PI3K/Akt pathway and is crucial for lung development, is essential for the prevention of alveolar flooding and lung fibrosis through the regulation of AEC barrier integrity after injury. Reestablishment of AEC barrier integrity also involves the deployment of specialized stem/progenitor cells.
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Azizi F, Arredouani A, Mohammad RM. Airway surface liquid volume expansion induces rapid changes in amiloride-sensitive Na+ transport across upper airway epithelium-Implications concerning the resolution of pulmonary edema. Physiol Rep 2015; 3:3/9/e12453. [PMID: 26333829 PMCID: PMC4600371 DOI: 10.14814/phy2.12453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
During airway inflammation, airway surface liquid volume (ASLV) expansion may result from the movement of plasma proteins and excess liquid into the airway lumen due to extravasation and elevation of subepithelial hydrostatic pressure. We previously demonstrated that elevation of submucosal hydrostatic pressure increases airway epithelium permeability resulting in ASLV expansion by 500 μL cm−2 h−1. Liquid reabsorption by healthy airway epithelium is regulated by active Na+ transport at a rate of 5 μL cm−2 h−1. Thus, during inflammation the airway epithelium may be submerged by a large volume of luminal liquid. Here, we have investigated the mechanism by which ASLV expansion alters active epithelial Na+ transport, and we have characterized the time course of the change. We used primary cultures of tracheal airway epithelium maintained under air interface (basal ASLV, depth is 7 ± 0.5 μm). To mimic airway flooding, ASLV was expanded to a depth of 5 mm. On switching from basal to expanded ASLV conditions, short-circuit current (Isc, a measure of total transepithelial active ion transport) declined by 90% with a half-time (t1/2) of 1 h. 24 h after the switch, there was no significant change in ATP concentration nor in the number of functional sodium pumps as revealed by [3H]-ouabain binding. However, amiloride-sensitive uptake of 22Na+ was reduced by 70% upon ASLV expansion. This process is reversible since after returning cells back to air interface, Isc recovered with a t1/2 of 5–10 h. These results may have important clinical implications concerning the development of Na+ channels activators and resolution of pulmonary edema.
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Affiliation(s)
- Fouad Azizi
- Interim Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | | | - Ramzi M Mohammad
- Interim Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
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Abstract
The unique characteristics of pulmonary circulation and alveolar-epithelial capillary-endothelial barrier allow for maintenance of the air-filled, fluid-free status of the alveoli essential for facilitating gas exchange, maintaining alveolar stability, and defending the lung against inhaled pathogens. The hallmark of pathophysiology in acute respiratory distress syndrome is the loss of the alveolar capillary permeability barrier and the presence of protein-rich edema fluid in the alveoli. This alteration in permeability and accumulation of fluid in the alveoli accompanies damage to the lung epithelium and vascular endothelium along with dysregulated inflammation and inappropriate activity of leukocytes and platelets. In addition, there is uncontrolled activation of coagulation along with suppression of fibrinolysis and loss of surfactant. These pathophysiological changes result in the clinical manifestations of acute respiratory distress syndrome, which include hypoxemia, radiographic opacities, decreased functional residual capacity, increased physiologic deadspace, and decreased lung compliance. Resolution of acute respiratory distress syndrome involves the migration of cells to the site of injury and re-establishment of the epithelium and endothelium with or without the development of fibrosis. Most of the data related to acute respiratory distress syndrome, however, originate from studies in adults or in mature animals with very few studies performed in children or juvenile animals. The lack of studies in children is particularly problematic because the lungs and immune system are still developing during childhood and consequently the pathophysiology of pediatric acute respiratory distress syndrome may differ in significant ways from that seen in acute respiratory distress syndrome in adults. This article describes what is known of the pathophysiologic processes of pediatric acute respiratory distress syndrome as we know it today while also presenting the much greater body of evidence on these processes as elucidated by adult and animal studies. It is also our expressed intent to generate enthusiasm for larger and more in-depth investigations of the mechanisms of disease and repair specific to children in the years to come.
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Schlingmann B, Molina SA, Koval M. Claudins: Gatekeepers of lung epithelial function. Semin Cell Dev Biol 2015; 42:47-57. [PMID: 25951797 DOI: 10.1016/j.semcdb.2015.04.009] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 04/24/2015] [Indexed: 12/25/2022]
Abstract
The lung must maintain a proper barrier between airspaces and fluid filled tissues in order to maintain lung fluid balance. Central to maintaining lung fluid balance are epithelial cells which create a barrier to water and solutes. The barrier function of these cells is mainly provided by tight junction proteins known as claudins. Epithelial barrier function varies depending on the different needs within the segments of the respiratory tree. In the lower airways, fluid is required to maintain mucociliary clearance, whereas in the terminal alveolar airspaces a thin layer of surfactant enriched fluid lowers surface tension to prevent airspace collapse and is critical for gas exchange. As the epithelial cells within the segments of the respiratory tree differ, the composition of claudins found in these epithelial cells is also different. Among these differences is claudin-18 which is uniquely expressed by the alveolar epithelial cells. Other claudins, notably claudin-4 and claudin-7, are more ubiquitously expressed throughout the respiratory epithelium. Claudin-5 is expressed by both pulmonary epithelial and endothelial cells. Based on in vitro and in vivo model systems and histologic analysis of lungs from human patients, roles for specific claudins in maintaining barrier function and protecting the lung from the effects of acute injury and disease are being identified. One surprising finding is that claudin-18 and claudin-4 control lung cell phenotype and inflammation beyond simply maintaining a selective paracellular permeability barrier. This suggests claudins have more nuanced roles for the control of airway and alveolar physiology in the healthy and diseased lung.
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Affiliation(s)
- Barbara Schlingmann
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Samuel A Molina
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States.
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Overgaard CE, Schlingmann B, Dorsainvil White S, Ward C, Fan X, Swarnakar S, Brown LAS, Guidot DM, Koval M. The relative balance of GM-CSF and TGF-β1 regulates lung epithelial barrier function. Am J Physiol Lung Cell Mol Physiol 2015; 308:L1212-23. [PMID: 25888574 DOI: 10.1152/ajplung.00042.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Lung barrier dysfunction is a cardinal feature of the acute respiratory distress syndrome (ARDS). Alcohol abuse, which increases the risk of ARDS two- to fourfold, induces transforming growth factor (TGF)-β1, which increases epithelial permeability and impairs granulocyte/macrophage colony-stimulating factor (GM-CSF)-dependent barrier integrity in experimental models. We hypothesized that the relative balance of GM-CSF and TGF-β1 signaling regulates lung epithelial barrier function. GM-CSF and TGF-β1 were tested separately and simultaneously for their effects on lung epithelial cell barrier function in vitro. TGF-β1 alone caused an ∼ 25% decrease in transepithelial resistance (TER), increased paracellular flux, and was associated with projections perpendicular to tight junctions ("spikes") containing claudin-18 that colocalized with F-actin. In contrast, GM-CSF treatment induced an ∼ 20% increase in TER, decreased paracellular flux, and showed decreased colocalization of spike-associated claudin-18 with F-actin. When simultaneously administered to lung epithelial cells, GM-CSF antagonized the effects of TGF-β1 on epithelial barrier function in cultured cells. Given this, GM-CSF and TGF-β1 levels were measured in bronchoalveolar lavage (BAL) fluid from patients with ventilator-associated pneumonia and correlated with markers for pulmonary edema and patient outcome. In patient BAL fluid, protein markers of lung barrier dysfunction, serum α2-macroglobulin, and IgM levels were increased at lower ratios of GM-CSF/TGF-β1. Critically, patients who survived had significantly higher GM-CSF/TGF-β1 ratios than nonsurviving patients. This study provides experimental and clinical evidence that the relative balance between GM-CSF and TGF-β1 signaling is a key regulator of lung epithelial barrier function. The GM-CSF/TGF-β1 ratio in BAL fluid may provide a concentration-independent biomarker that can predict patient outcomes in ARDS.
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Affiliation(s)
- Christian E Overgaard
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia
| | - Barbara Schlingmann
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia
| | - StevenClaude Dorsainvil White
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia
| | - Christina Ward
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia
| | - Xian Fan
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Atlanta Veterans Affairs Medical Center, Decatur, Georgia
| | - Snehasikta Swarnakar
- Drug Development Diagnostics and Biotechnology, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Lou Ann S Brown
- Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia; Division of Neonatology, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia
| | - David M Guidot
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia; Atlanta Veterans Affairs Medical Center, Decatur, Georgia
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, Georgia; Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia; Department of Cell Biology, Emory University, Atlanta, Georgia;
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Ward C, Schlingmann B, Stecenko AA, Guidot DM, Koval M. NF-κB inhibitors impair lung epithelial tight junctions in the absence of inflammation. Tissue Barriers 2015; 3:e982424. [PMID: 25838984 DOI: 10.4161/21688370.2014.982424] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 10/27/2014] [Indexed: 01/11/2023] Open
Abstract
NF-κB (p50/p65) is the best characterized transcription factor known to regulate cell responses to inflammation. However, NF-κB is also constitutively expressed. We used inhibitors of the classical NF-κB signaling pathway to determine whether this transcription factor has a role in regulating alveolar epithelial tight junctions. Primary rat type II alveolar epithelial cells were isolated and cultured on Transwell permeable supports coated with collagen for 5 d to generate a model type I cell monolayer. Treatment of alveolar epithelial monolayers overnight with one of 2 different IκB kinase inhibitors (BAY 11-7082 or BMS-345541) resulted in a dose-dependent decrease in TER at concentrations that did not affect cell viability. In response to BMS-345541 treatment there was an increase in total claudin-4 and claudin-5 along with a decrease in claudin-18, as determined by immunoblot. However, there was little effect on the total amount of cell-associated claudin-7, occludin, junctional adhesion molecule A (JAM-A), zonula occludens (ZO)-1 or ZO-2. Moreover, treatment with BMS-345541 resulted in altered tight junction morphology as assessed by immunofluorescence microscopy. Cells treated with BMS-345541 had an increase in claudin-18 containing projections emanating from tight junctions ("spikes") that were less prominent in control cells. There also were several areas of cell-cell contact which lacked ZO-1 and ZO-2 localization as well as rearrangements to the actin cytoskeleton in response to BMS-345541. Consistent with an anti-inflammatory effect, BMS-345541 antagonized the deleterious effects of lipopolysaccharide (LPS) on alveolar epithelial barrier function. However, BMS-345541 also inhibited the ability of GM-CSF to increase alveolar epithelial TER. These data suggest a dual role for NF-κB in regulating alveolar barrier function and that constitutive NF-κB function is required for the integrity of alveolar epithelial tight junctions.
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Key Words
- ARDS, Acute Respiratory Distress Syndrome
- GM-CSF, Granulocyte Macrophage Colony Stimulating Factor
- IL, interleukin
- IκB, Inhibitor of κB
- JAM-A, junctional adhesion molecule A
- LPS, lipolysaccharide
- NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells
- PBS, phosphate buffered saline
- TER, transepithelial resistance
- TNF, Tumor Necrosis Factor
- ZO, zonula occludens
- alveolus
- claudin
- lung barrier
- tight junction
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Affiliation(s)
- Christina Ward
- Pulmonary Division; Department of Medicine; Emory University School of Medicine ; Atlanta, GA USA
| | - Barbara Schlingmann
- Pulmonary Division; Department of Medicine; Emory University School of Medicine ; Atlanta, GA USA
| | - Arlene A Stecenko
- Department of Pediatrics; Emory University School of Medicine ; Atlanta, GA USA
| | - David M Guidot
- Pulmonary Division; Department of Medicine; Emory University School of Medicine ; Atlanta, GA USA
| | - Michael Koval
- Pulmonary Division; Department of Medicine; Emory University School of Medicine ; Atlanta, GA USA ; Department of Cell Biology; Emory University School of Medicine ; Atlanta, GA USA
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Brune K, Frank J, Schwingshackl A, Finigan J, Sidhaye VK. Pulmonary epithelial barrier function: some new players and mechanisms. Am J Physiol Lung Cell Mol Physiol 2015; 308:L731-45. [PMID: 25637609 DOI: 10.1152/ajplung.00309.2014] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/27/2015] [Indexed: 12/20/2022] Open
Abstract
The pulmonary epithelium serves as a barrier to prevent access of the inspired luminal contents to the subepithelium. In addition, the epithelium dictates the initial responses of the lung to both infectious and noninfectious stimuli. One mechanism by which the epithelium does this is by coordinating transport of diffusible molecules across the epithelial barrier, both through the cell and between cells. In this review, we will discuss a few emerging paradigms of permeability changes through altered ion transport and paracellular regulation by which the epithelium gates its response to potentially detrimental luminal stimuli. This review is a summary of talks presented during a symposium in Experimental Biology geared toward novel and less recognized methods of epithelial barrier regulation. First, we will discuss mechanisms of dynamic regulation of cell-cell contacts in the context of repetitive exposure to inhaled infectious and noninfectious insults. In the second section, we will briefly discuss mechanisms of transcellular ion homeostasis specifically focused on the role of claudins and paracellular ion-channel regulation in chronic barrier dysfunction. In the next section, we will address transcellular ion transport and highlight the role of Trek-1 in epithelial responses to lung injury. In the final section, we will outline the role of epithelial growth receptor in barrier regulation in baseline, acute lung injury, and airway disease. We will then end with a summary of mechanisms of epithelial control as well as discuss emerging paradigms of the epithelium role in shifting between a structural element that maintains tight cell-cell adhesion to a cell that initiates and participates in immune responses.
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Affiliation(s)
- Kieran Brune
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| | - James Frank
- The Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco VA Medical Center, and NCIRE/Veterans Health Research Institute, San Francisco, California
| | - Andreas Schwingshackl
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
| | - James Finigan
- Division of Oncology, Cancer Center, National Jewish Health, Denver, Colorado
| | - Venkataramana K Sidhaye
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland;
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Junctional adhesion molecule A promotes epithelial tight junction assembly to augment lung barrier function. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 185:372-86. [PMID: 25438062 DOI: 10.1016/j.ajpath.2014.10.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 09/12/2014] [Accepted: 10/15/2014] [Indexed: 12/14/2022]
Abstract
Epithelial barrier function is maintained by tight junction proteins that control paracellular fluid flux. Among these proteins is junctional adhesion molecule A (JAM-A), an Ig fold transmembrane protein. To assess JAM-A function in the lung, we depleted JAM-A in primary alveolar epithelial cells using shRNA. In cultured cells, loss of JAM-A caused an approximately 30% decrease in transepithelial resistance, decreased expression of the tight junction scaffold protein zonula occludens 1, and disrupted junctional localization of the structural transmembrane protein claudin-18. Consistent with findings in other organs, loss of JAM-A decreased β1 integrin expression and impaired filamentous actin formation. Using a model of mild systemic endoxotemia induced by i.p. injection of lipopolysaccharide, we report that JAM-A(-/-) mice showed increased susceptibility to pulmonary edema. On injury, the enhanced susceptibility of JAM-A(-/-) mice to edema correlated with increased, transient disruption of claudin-18, zonula occludens 1, and zonula occludens 2 localization to lung tight junctions in situ along with a delay in up-regulation of claudin-4. In contrast, wild-type mice showed no change in lung tight junction morphologic features in response to mild systemic endotoxemia. These findings support a key role of JAM-A in promoting tight junction homeostasis and lung barrier function by coordinating interactions among claudins, the tight junction scaffold, and the cytoskeleton.
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LaFemina MJ, Sutherland KM, Bentley T, Gonzales LW, Allen L, Chapin CJ, Rokkam D, Sweerus KA, Dobbs LG, Ballard PL, Frank JA. Claudin-18 deficiency results in alveolar barrier dysfunction and impaired alveologenesis in mice. Am J Respir Cell Mol Biol 2014; 51:550-8. [PMID: 24787463 DOI: 10.1165/rcmb.2013-0456oc] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Claudins are a family of transmembrane proteins that are required for tight junction formation. Claudin (CLDN)-18.1, the only known lung-specific tight junction protein, is the most abundant claudin in alveolar epithelial type (AT) 1 cells, and is regulated by lung maturational agonists and inflammatory mediators. To determine the function of CLDN18 in the alveolar epithelium, CLDN18 knockout (KO) mice were generated and studied by histological, biochemical, and physiological approaches, in addition to whole-genome microarray. Alveolar epithelial barrier function was assessed after knockdown of CLDN18 in isolated lung cells. CLDN18 levels were measured by quantitative PCR in lung samples from fetal and postnatal human infants. We found that CLDN18 deficiency impaired alveolar epithelial barrier function in vivo and in vitro, with evidence of increased paracellular permeability and architectural distortion at AT1-AT1 cell junctions. Although CLDN18 KO mice were born without evidence of a lung abnormality, histological and gene expression analysis at Postnatal Day 3 and Week 4 identified impaired alveolarization. CLDN18 KO mice also had evidence of postnatal lung injury, including acquired AT1 cell damage. Human fetal lungs at 23-24 weeks gestational age, the highest-risk period for developing bronchopulmonary dysplasia, a disease of impaired alveolarization, had significantly lower CLDN18 expression relative to postnatal lungs. Thus, CLDN18 deficiency results in epithelial barrier dysfunction, injury, and impaired alveolarization in mice. Low expression of CLDN18 in human fetal lungs supports further investigation into a role for this tight junction protein in bronchopulmonary dysplasia.
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Kage H, Flodby P, Gao D, Kim YH, Marconett CN, DeMaio L, Kim KJ, Crandall ED, Borok Z. Claudin 4 knockout mice: normal physiological phenotype with increased susceptibility to lung injury. Am J Physiol Lung Cell Mol Physiol 2014; 307:L524-36. [PMID: 25106430 DOI: 10.1152/ajplung.00077.2014] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Claudins are tight junction proteins that regulate paracellular ion permeability of epithelium and endothelium. Claudin 4 has been reported to function as a paracellular sodium barrier and is one of three major claudins expressed in lung alveolar epithelial cells (AEC). To directly assess the role of claudin 4 in regulation of alveolar epithelial barrier function and fluid homeostasis in vivo, we generated claudin 4 knockout (Cldn4 KO) mice. Unexpectedly, Cldn4 KO mice exhibited normal physiological phenotype although increased permeability to 5-carboxyfluorescein and decreased alveolar fluid clearance were noted. Cldn4 KO AEC monolayers exhibited unchanged ion permeability, higher solute permeability, and lower short-circuit current compared with monolayers from wild-type mice. Claudin 3 and 18 expression was similar between wild-type and Cldn4 KO alveolar epithelial type II cells. In response to either ventilator-induced lung injury or hyperoxia, claudin 4 expression was markedly upregulated in wild-type mice, whereas Cldn4 KO mice showed greater degrees of lung injury. RNA sequencing, in conjunction with differential expression and upstream analysis after ventilator-induced lung injury, suggested Egr1, Tnf, and Il1b as potential mediators of increased lung injury in Cldn4 KO mice. These results demonstrate that claudin 4 has little effect on normal lung physiology but may function to protect against acute lung injury.
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Affiliation(s)
- Hidenori Kage
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Per Flodby
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Danping Gao
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Yong Ho Kim
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Crystal N Marconett
- Departments of Surgery and Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center
| | - Lucas DeMaio
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine
| | - Kwang-Jin Kim
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Departments of Physiology and Biophysics and Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California; Department of Biomedical Engineering and
| | - Edward D Crandall
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Pathology, Keck School of Medicine, University of Southern California; Mork Family Department of Chemical Engineering and Materials Science, Viterbi School of Engineering, University of Southern California, Los Angeles, California
| | - Zea Borok
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center,
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Zheng Y, Zhang M, Zhao Y, Chen J, Li B, Cai W. JNK inhibitor SP600125 protects against lipopolysaccharide-induced acute lung injury via upregulation of claudin-4. Exp Ther Med 2014; 8:153-158. [PMID: 24944614 PMCID: PMC4061205 DOI: 10.3892/etm.2014.1684] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/18/2014] [Indexed: 11/05/2022] Open
Abstract
Although in vitro studies have previously demonstrated that mitogen-activated protein kinases are important for the activation of transcription factors and the regulation of proinflammatory mediators, the function of c-Jun NH2-terminal kinase (JNK) in acute lung injury (ALI) remains to be fully elucidated. The present study aimed to investigate the effect of the JNK selective inhibitor SP600125 on lipopolysaccharide (LPS)-induced ALI. Pulmonary edema, the expression of inflammatory cytokines and pathological alterations were found to be significantly attenuated in LPS-induced ALI following treatment with SP600125 in vivo. In vitro, it was demonstrated that SP600125 administration significantly improved A549 cell viability in a dose-dependent manner using the Cell Counting kit-8 and the 5-ethynyl-2'-deoxyuridine incorporation assay. Furthermore, flow cytometric analysis demonstrated that the apoptotic rate was significantly reduced in a concentration-dependent manner following SP600125 injection. At the molecular level, SP600125 treatment dose-dependently inhibited JNK activation and upregulated claudin-4 expression in vivo and in vitro. In combination, the results from the present study indicated that the JNK inhibitor SP600125 protected against LPS-induced ALI in vivo and in vitro, possibly by upregulating the expression of claudin-4.
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Affiliation(s)
- Yueliang Zheng
- Department of Emergency, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310014, P.R. China
| | - Meiqi Zhang
- Department of Emergency, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310014, P.R. China
| | - Yiming Zhao
- Department of Emergency, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310014, P.R. China
| | - Jie Chen
- Department of Emergency, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310014, P.R. China
| | - Bing Li
- Department of Emergency, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310014, P.R. China
| | - Wenwei Cai
- Department of Emergency, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310014, P.R. China
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64
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Herold S, Gabrielli NM, Vadász I. Novel concepts of acute lung injury and alveolar-capillary barrier dysfunction. Am J Physiol Lung Cell Mol Physiol 2013; 305:L665-81. [PMID: 24039257 DOI: 10.1152/ajplung.00232.2013] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In this review we summarize recent major advances in our understanding on the molecular mechanisms, mediators, and biomarkers of acute lung injury (ALI) and alveolar-capillary barrier dysfunction, highlighting the role of immune cells, inflammatory and noninflammatory signaling events, mechanical noxae, and the affected cellular and molecular entities and functions. Furthermore, we address novel aspects of resolution and repair of ALI, as well as putative candidates for treatment of ALI, including pharmacological and cellular therapeutic means.
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Affiliation(s)
- Susanne Herold
- Dept. of Internal Medicine, Justus Liebig Univ., Universities of Giessen and Marburg Lung Center, Klinikstrasse 33, 35392 Giessen, Germany.
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65
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Abstract
The distal airways are covered with a heterogeneous layer of cells known as the alveolar epithelium. Alveolar epithelial cells provide the major barrier between the airspace and fluid filled tissue compartments. As such, regulation of the alveolar epithelium is critical to maintain a healthy lung and for optimal gas exchange. In this chapter, we discuss functional roles for alveolar epithelial cells with particular emphasis on intercellular junctions and communication. As a thin layer of cells directly exposed to atmospheric oxygen, alveoli are particularly sensitive to oxidant insults. Alcohol significantly diminishes the normal antioxidant reserves of the alveolar epithelium, thereby rendering it sensitized for an exaggerated damage response to acute and chronic injuries. The effects of alcohol on alveolar epithelia are discussed along with open questions and potential therapeutic targets to prevent the pathophysiology of alcoholic lung disease.
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66
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Jin W, Rong L, Liu Y, Song Y, Li Y, Pan J. Increased claudin-3, -4 and -18 levels in bronchoalveolar lavage fluid reflect severity of acute lung injury. Respirology 2013; 18:643-51. [PMID: 23253121 DOI: 10.1111/resp.12034] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/09/2012] [Indexed: 11/30/2022]
Affiliation(s)
| | - Linyi Rong
- Department of Pulmonary Medicine; Zhongshan Hospital, Fudan University; Shanghai; China
| | | | | | | | - Jue Pan
- Department of Pulmonary Medicine; Zhongshan Hospital, Fudan University; Shanghai; China
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67
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Rittirsch D, Flierl MA, Nadeau BA, Day DE, Huber-Lang MS, Grailer JJ, Zetoune FS, Andjelkovic AV, Fasano A, Ward PA. Zonulin as prehaptoglobin2 regulates lung permeability and activates the complement system. Am J Physiol Lung Cell Mol Physiol 2013; 304:L863-72. [PMID: 23564505 DOI: 10.1152/ajplung.00196.2012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Zonulin is a protein involved in the regulation of tight junctions (TJ) in epithelial or endothelial cells. Zonulin is known to affect TJ in gut epithelial cells, but little is known about its influences in other organs. Prehaptoglobin2 has been identified as zonulin and is related to serine proteases (MASPs, C1qrs) that activate the complement system. The current study focused on the role of zonulin in development of acute lung injury (ALI) in C57BL/6 male mice following intrapulmonary deposition of IgG immune complexes. A zonulin antagonist (AT-1001) and a related peptide with permeability agonist activities (AT-1002) were employed and given intratracheally or intravenously. Also, zonulin was blocked in lung with a neutralizing antibody. In a dose-dependent manner, AT-1001 or zonulin neutralizing antibody attenuated the intensity of ALI (as quantitated by albumin leak, neutrophil accumulation, and proinflammatory cytokines). A similar pattern was found using the bacterial lipopolysaccharide model of ALI. Using confocal microscopy on sections of injured lungs, staining patterns for TJ proteins were discontinuous, reduced, and fragmented. As expected, the leak of blood products into the alveolar space confirmed the passage of 3 and 20 kDa dextran, and albumin. In contrast to AT-1001, application of the zonulin agonist AT-1002 intensified ALI. Zonulin both in vitro and in vivo induced generation of complement C3a and C5a. Collectively, these data suggest that zonulin facilitates development of ALI both by enhancing albumin leak and complement activation as well as increased buildup of neutrophils and cytokines during development of ALI.
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Affiliation(s)
- Daniel Rittirsch
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA.
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68
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Abstract
Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction permeability. This review summarizes our current knowledge of this large protein family and discusses recent advances in our understanding of their structure and physiological functions.
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Affiliation(s)
- Dorothee Günzel
- Department of Clinical Physiology, Charité, Campus Benjamin Franklin, Berlin, Germany
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69
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Bhattacharya J, Matthay MA. Regulation and repair of the alveolar-capillary barrier in acute lung injury. Annu Rev Physiol 2013; 75:593-615. [PMID: 23398155 DOI: 10.1146/annurev-physiol-030212-183756] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Considerable progress has been made in understanding the basic mechanisms that regulate fluid and protein exchange across the endothelial and epithelial barriers of the lung under both normal and pathological conditions. Clinically relevant lung injury occurs most commonly from severe viral and bacterial infections, aspiration syndromes, and severe shock. The mechanisms of lung injury have been identified in both experimental and clinical studies. Recovery from lung injury requires the reestablishment of an intact endothelial barrier and a functional alveolar epithelial barrier capable of secreting surfactant and removing alveolar edema fluid. Repair mechanisms include the participation of endogenous progenitor cells in strategically located niches in the lung. Novel treatment strategies include the possibility of cell-based therapy that may reduce the severity of lung injury and enhance lung repair.
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Affiliation(s)
- Jahar Bhattacharya
- Division of Pulmonary Allergy and Critical Care, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA.
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70
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Lappi-Blanco E, Lehtonen ST, Sormunen R, Merikallio HM, Soini Y, Kaarteenaho RL. Divergence of tight and adherens junction factors in alveolar epithelium in pulmonary fibrosis. Hum Pathol 2012; 44:895-907. [PMID: 23253490 DOI: 10.1016/j.humpath.2012.08.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 11/17/2022]
Abstract
It has been proposed that an epithelial injury may be one of the multiple primary events in the pathogenesis of idiopathic pulmonary fibrosis (IPF). The aim of this study was to characterize the tight junction and adherens junction proteins in normal human lung, IPF, cryptogenic organizing pneumonia, and asbestosis. We determined the immunohistochemical cell-specific expression of tight junction proteins claudin-1, claudin-2, claudin-3, claudin-4, claudin-5, and claudin-7, as well as 3 adherens junction proteins, E-cadherin, N-cadherin, and β-catenin. We further analyzed the expression of claudin-1, claudin-3, and claudin-4 and E-cadherin, N-cadherin, and β-catenin at the transcriptional level by quantitative real-time reverse transcriptase polymerase chain reaction. The expression levels of both tight junction and adherens junction proteins were elevated in regenerative alveolar epithelium in pulmonary fibrosis as compared with the expression of these proteins in normal alveolar epithelium. In particular, the expression levels of claudins-1 and claudin-3 were clearly elevated in all diseases. Furthermore, the amounts of adherens junction proteins messenger RNAs (mRNAs) were also all increased in pulmonary fibroses in comparison with healthy controls, with N-cadherin showing the greatest increase in mRNA levels in all diseases. However, the amounts of claudin-1, claudin-3, and claudin-4 mRNAs in fibrotic lung were similar to or even lower than those measured in the healthy controls. It is possible that the diminished capacity to produce claudin mRNAs may be one explanation for poor repair capacity of alveolar epithelial cells in IPF.
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71
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Overgaard CE, Mitchell LA, Koval M. Roles for claudins in alveolar epithelial barrier function. Ann N Y Acad Sci 2012; 1257:167-74. [PMID: 22671603 DOI: 10.1111/j.1749-6632.2012.06545.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Terminal airspaces of the lung, alveoli, are sites of gas exchange that are sensitive to disrupted fluid balance. The alveolar epithelium is a heterogeneous monolayer of cells interconnected by tight junctions at sites of cell-cell contact. Paracellular permeability depends on claudin (cldn)-family tight junction proteins. Of over a dozen alveolar cldns, cldn-3, cldn-4, and cldn-18 are the most highly expressed; other prominent alveolar claudins include cldn-5 and cldn-7. Cldn-3 is primarily expressed by type II alveolar epithelial cells, whereas cldn-4 and cldn-18 are expressed throughout the alveolar epithelium. Lung diseases associated with pulmonary edema, such as alcoholic lung syndrome and acute lung injury, affect alveolar claudin expression, which is frequently associated with impaired fluid clearance due to increased alveolar leak. However, recent studies have identified a role for increased cldn-4 in protecting alveolar barrier function following injury. Thus, alveolar claudins are dynamically regulated, tailoring lung barrier function to control the air-liquid interface.
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Affiliation(s)
- Christian E Overgaard
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia, USA
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72
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Abstract
The alveolar epithelium of the lung constitutes a unique interface with the outside environment. This thin barrier must maintain a surface for gas transfer while being continuously exposed to potentially hazardous environmental stimuli. Small differences in alveolar epithelial barrier properties could therefore have a large impact on disease susceptibility or outcome. Moreover, recent work has focused attention on the alveolar epithelium as central to several lung diseases, including acute lung injury and idiopathic pulmonary fibrosis. Although relatively little is known about the function and regulation of claudin tight junction proteins in the lung, new evidence suggests that environmental stimuli can influence claudin expression and alveolar barrier function in human disease. This review considers recent advances in the understanding of the role of claudins in the breakdown of the alveolar epithelial barrier in disease and in epithelial repair.
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Affiliation(s)
- James A Frank
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, USA.
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73
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Abstract
Lung epithelial cells interconnected by tight junctions provide a barrier to the free diffusion of solutes into airspaces. Transmembrane tight junction proteins known as claudins are essential for epithelial barrier function. Claudins are regulated through interactions with each other that are coordinated with other transmembrane tight junction proteins and cytosolic scaffold proteins. Of the 14 claudins expressed by the alveolar epithelium, claudin-3, claudin-4, and claudin-18 are the most prominent; each confers unique properties to alveolar barrier function. In particular, a protective role for claudin-4 in preventing lung injury has emerged. By contrast, lung diseases that affect claudin expression and impair barrier function, including alcoholic lung syndrome and sepsis, prime the lung for pulmonary edema. Thus, approaches to restore and/or augment lung claudin expression provide potential targets for promoting healthy barrier function.
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Affiliation(s)
- Michael Koval
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, Georgia 30322, USA.
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74
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Jacob AM, Gaver DP. Atelectrauma disrupts pulmonary epithelial barrier integrity and alters the distribution of tight junction proteins ZO-1 and claudin 4. J Appl Physiol (1985) 2012; 113:1377-87. [PMID: 22898551 DOI: 10.1152/japplphysiol.01432.2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mechanical ventilation inevitably exposes the delicate tissues of the airways and alveoli to abnormal mechanical stresses that can induce pulmonary edema and exacerbate conditions such as acute respiratory distress syndrome. The goal of our research is to characterize the cellular trauma caused by the transient abnormal fluid mechanical stresses that arise when air is forced into a liquid-occluded airway (i.e., atelectrauma). Using a fluid-filled, parallel-plate flow chamber to model the "airway reopening" process, our in vitro study examined consequent increases in pulmonary epithelial plasma membrane rupture, paracellular permeability, and disruption of the tight junction (TJ) proteins zonula occludens-1 and claudin-4. Computational analysis predicts the normal and tangential surface stresses that develop between the basolateral epithelial membrane and underlying substrate due to the interfacial stresses acting on the apical cell membrane. These simulations demonstrate that decreasing the velocity of reopening causes a significant increase in basolateral surface stresses, particularly in the region between neighboring cells where TJs concentrate. Likewise, pulmonary epithelial wounding, paracellular permeability, and TJ protein disruption were significantly greater following slower reopening. This study thus demonstrates that maintaining a higher velocity of reopening, which reduces the damaging fluid stresses acting on the airway wall, decreases the mechanical stresses on the basolateral cell surface while protecting cells from plasma membrane rupture and promoting barrier integrity.
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Affiliation(s)
- Anne-Marie Jacob
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisana 70118, USA
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