1
|
Lemmens-Gruber R, Tzotzos S. The Epithelial Sodium Channel-An Underestimated Drug Target. Int J Mol Sci 2023; 24:ijms24097775. [PMID: 37175488 PMCID: PMC10178586 DOI: 10.3390/ijms24097775] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 05/15/2023] Open
Abstract
Epithelial sodium channels (ENaC) are part of a complex network of interacting biochemical pathways and as such are involved in several disease states. Dependent on site and type of mutation, gain- or loss-of-function generated symptoms occur which span from asymptomatic to life-threatening disorders such as Liddle syndrome, cystic fibrosis or generalized pseudohypoaldosteronism type 1. Variants of ENaC which are implicated in disease assist further understanding of their molecular mechanisms in order to create models for specific pharmacological targeting. Identification and characterization of ENaC modifiers not only furthers our basic understanding of how these regulatory processes interact, but also enables discovery of new therapeutic targets for the disease conditions caused by ENaC dysfunction. Numerous test compounds have revealed encouraging results in vitro and in animal models but less in clinical settings. The EMA- and FDA-designated orphan drug solnatide is currently being tested in phase 2 clinical trials in the setting of acute respiratory distress syndrome, and the NOX1/ NOX4 inhibitor setanaxib is undergoing clinical phase 2 and 3 trials for therapy of primary biliary cholangitis, liver stiffness, and carcinoma. The established ENaC blocker amiloride is mainly used as an add-on drug in the therapy of resistant hypertension and is being studied in ongoing clinical phase 3 and 4 trials for special applications. This review focuses on discussing some recent developments in the search for novel therapeutic agents.
Collapse
Affiliation(s)
- Rosa Lemmens-Gruber
- Department of Pharmaceutical Sciences, Division of Pharmacology and Toxicology, University of Vienna, A-1090 Vienna, Austria
| | | |
Collapse
|
2
|
Martin-Malpartida P, Arrastia-Casado S, Farrera-Sinfreu J, Lucas R, Fischer H, Fischer B, Eaton DC, Tzotzos S, Macias MJ. Conformational ensemble of the TNF-derived peptide solnatide in solution. Comput Struct Biotechnol J 2022; 20:2082-2090. [PMID: 35601958 PMCID: PMC9079168 DOI: 10.1016/j.csbj.2022.04.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/21/2022] [Accepted: 04/21/2022] [Indexed: 12/12/2022] Open
Abstract
Tumor necrosis factor (TNF) is a homotrimer that has two spatially distinct binding regions, three lectin-like domains (LLD) at the TIP of the protein and three basolaterally located receptor-binding sites, the latter of which are responsible for the inflammatory and cell death-inducing properties of the cytokine. Solnatide (a.k.a. TIP peptide, AP301) is a 17-mer cyclic peptide that mimics the LLD of human TNF which activates the amiloride-sensitive epithelial sodium channel (ENaC) and, as such, recapitulates the capacity of TNF to enhance alveolar fluid clearance, as demonstrated in numerous preclinical studies. TNF and solnatide interact with glycoproteins and these interactions are necessary for their trypanolytic and ENaC-activating activities. In view of the crucial role of ENaC in lung liquid clearance, solnatide is currently being evaluated as a novel therapeutic agent to treat pulmonary edema in patients with moderate-to-severe acute respiratory distress syndrome (ARDS), as well as severe COVID-19 patients with ARDS. To facilitate the description of the functional properties of solnatide in detail, as well as to further target-docking studies, we have analyzed its folding properties by NMR. In solution, solnatide populates a set of conformations characterized by a small hydrophobic core and two electrostatically charged poles. Using the structural information determined here and also that available for the ENaC protein, we propose a model to describe solnatide interaction with the C-terminal domain of the ENaCα subunit. This model may serve to guide future experiments to validate specific interactions with ENaCα and the design of new solnatide analogs with unexplored functionalities.
Collapse
Key Words
- AP301 peptide
- ARDS, Acute Respiratory Distress Syndrome
- AlphaFold applications
- Alveolar fluid clearance
- Amiloride-sensitive epithelial sodium channel
- Amphipathic helix
- ENaC
- ENaC, Amiloride-sensitive Epithelial Sodium/Channel
- HPLC, High Performance Liquid Chromatography
- HSQC, Heteronuclear Single Quantum Coherence
- LLD, Lectin-Like Domains
- MARCKS, Myristoylated Alanine-Rich C Kinase Substrate
- NMR, Nuclear Magnetic Resonance
- NOESY, Nuclear Overhauser Effect Spectroscopy
- PIP2, Phosphatidylinositol Bisphosphate
- Peptide NMR
- Pulmonary edema
- Solnatide structure
- TIP peptide
- TM, Transmembrane Regions
- TNF, Tumor Necrosis Factor
- TOCSY, Total Correlation Spectroscopy
- Tumor necrosis factor
Collapse
Affiliation(s)
- Pau Martin-Malpartida
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain
| | | | | | - Rudolf Lucas
- Vascular Biology Center, Dept of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Hendrik Fischer
- APEPTICO Forschung und Entwicklung GmbH, Mariahilferstraße 136, 1150 Vienna, Austria
| | - Bernhard Fischer
- APEPTICO Forschung und Entwicklung GmbH, Mariahilferstraße 136, 1150 Vienna, Austria
| | - Douglas C. Eaton
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Susan Tzotzos
- APEPTICO Forschung und Entwicklung GmbH, Mariahilferstraße 136, 1150 Vienna, Austria
| | - Maria J. Macias
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona 08010, Spain
| |
Collapse
|
3
|
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.
Collapse
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,
| |
Collapse
|
4
|
Yang G, Pillich H, White R, Czikora I, Pochic I, Yue Q, Hudel M, Gorshkov B, Verin A, Sridhar S, Isales CM, Eaton DC, Hamacher J, Chakraborty T, Lucas R. Listeriolysin O Causes ENaC Dysfunction in Human Airway Epithelial Cells. Toxins (Basel) 2018; 10:toxins10020079. [PMID: 29439494 PMCID: PMC5848180 DOI: 10.3390/toxins10020079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/01/2018] [Accepted: 02/07/2018] [Indexed: 01/22/2023] Open
Abstract
Pulmonary permeability edema is characterized by reduced alveolar Na⁺ uptake capacity and capillary barrier dysfunction and is a potentially lethal complication of listeriosis. Apical Na⁺ uptake is mainly mediated by the epithelial sodium channel (ENaC) and initiates alveolar liquid clearance. Here we examine how listeriolysin O (LLO), the pore-forming toxin of Listeria monocytogenes, impairs the expression and activity of ENaC. To that purpose, we studied how sub-lytic concentrations of LLO affect negative and positive regulators of ENaC expression in the H441 airway epithelial cell line. LLO reduced expression of the crucial ENaC-α subunit in H441 cells within 2 h and this was preceded by activation of PKC-α, a negative regulator of the channel's expression. At later time points, LLO caused a significant reduction in the phosphorylation of Sgk-1 at residue T256 and of Akt-1 at residue S473, both of which are required for full activation of ENaC. The TNF-derived TIP peptide prevented LLO-mediated PKC-α activation and restored phospho-Sgk-1-T256. The TIP peptide also counteracted the observed LLO-induced decrease in amiloride-sensitive Na⁺ current and ENaC-α expression in H441 cells. Intratracheally instilled LLO caused profound pulmonary edema formation in mice, an effect that was prevented by the TIP peptide; thus indicating the therapeutic potential of the peptide for the treatment of pore-forming toxin-associated permeability edema.
Collapse
Affiliation(s)
- Guang Yang
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Helena Pillich
- Institute of Medical Microbiology, Justus-Liebig University Giessen, 35392 Gießen, Germany.
| | - Richard White
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
- Department of Biomedical Sciences, Georgia Campus-Philadelphia College of Osteopathic Medicine, Atlanta, GA 30224, USA.
| | - Istvan Czikora
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Isabelle Pochic
- Biochemical Pharmacology, University of Konstanz, 78464 Konstanz, Germany.
- Sandoz Inc., 83607 Holzkirchen, Germany.
| | - Qiang Yue
- Department of Physiology, Emory School of Medicine, Atlanta, GA 30307, USA.
| | - Martina Hudel
- Institute of Medical Microbiology, Justus-Liebig University Giessen, 35392 Gießen, Germany.
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Alexander Verin
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Supriya Sridhar
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
| | - Carlos M Isales
- Department of Medicine, Medical College of Georgia, Augusta, GA 30901, USA.
| | - Douglas C Eaton
- Department of Physiology, Emory School of Medicine, Atlanta, GA 30307, USA.
| | - Jürg Hamacher
- Biochemical Pharmacology, University of Konstanz, 78464 Konstanz, Germany.
- Department of Pneumology, Lindenhofspital, 3001 Bern, Switzerland.
- Internal, Pulmonary and Critical Care Medicine, Saarland University, 66424 Homburg/Saar, Germany.
- Lungen-und Atmungsstifung, 3001 Bern, Switzerland.
| | - Trinad Chakraborty
- Institute of Medical Microbiology, Justus-Liebig University Giessen, 35392 Gießen, Germany.
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Room CB-3213B, Augusta, GA 30912-2500, USA.
- Department of Medicine, Medical College of Georgia, Augusta, GA 30901, USA.
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Krenn K, Lucas R, Croizé A, Boehme S, Klein KU, Hermann R, Markstaller K, Ullrich R. Inhaled AP301 for treatment of pulmonary edema in mechanically ventilated patients with acute respiratory distress syndrome: a phase IIa randomized placebo-controlled trial. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:194. [PMID: 28750677 PMCID: PMC5531100 DOI: 10.1186/s13054-017-1795-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/12/2017] [Indexed: 02/08/2023]
Abstract
Background High-permeability pulmonary edema is a hallmark of acute respiratory distress syndrome (ARDS) and is frequently accompanied by impaired alveolar fluid clearance (AFC). AP301 enhances AFC by activating epithelial sodium channels (ENaCs) on alveolar epithelial cells, and we investigated its effect on extravascular lung water index (EVLWI) in mechanically ventilated patients with ARDS. Methods Forty adult mechanically ventilated patients with ARDS were included in a randomized, double-blind, placebo-controlled trial for proof of concept. Patients were treated with inhaled AP301 (n = 20) or placebo (0.9% NaCl; n = 20) twice daily for 7 days. EVLWI was measured by thermodilution (PiCCO®), and treatment groups were compared using the nonparametric Mann–Whitney U test. Results AP301 inhalation was well tolerated. No differences in mean baseline-adjusted change in EVLWI from screening to day 7 were found between the AP301 and placebo group (p = 0.196). There was no difference in the PaO2/FiO2 ratio, ventilation pressures, Murray lung injury score, or 28-day mortality between the treatment groups. An exploratory subgroup analysis according to severity of illness showed reductions in EVLWI (p = 0.04) and ventilation pressures (p < 0.05) over 7 days in patients with initial sequential organ failure assessment (SOFA) scores ≥11 inhaling AP301 versus placebo, but not in patients with SOFA scores ≤10. Conclusions There was no difference in mean baseline-adjusted EVLWI between the AP301 and placebo group. An exploratory post-hoc subgroup analysis indicated reduced EVLWI in patients with SOFA scores ≥11 receiving AP301. These results suggest further confirmation in future clinical trials of inhaled AP301 for treatment of pulmonary edema in patients with ARDS. Trial registration The study was prospectively registered at clinicaltrials.gov, NCT01627613. Registered 20 June 2012. Electronic supplementary material The online version of this article (doi:10.1186/s13054-017-1795-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Katharina Krenn
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology and Division of Pulmonary and Critical Care Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Adrien Croizé
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Stefan Boehme
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Klaus Ulrich Klein
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | | | - Klaus Markstaller
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria
| | - Roman Ullrich
- Department of Anaesthesia, Critical Care and Pain Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria.
| |
Collapse
|
7
|
Czikora I, Alli AA, Sridhar S, Matthay MA, Pillich H, Hudel M, Berisha B, Gorshkov B, Romero MJ, Gonzales J, Wu G, Huo Y, Su Y, Verin AD, Fulton D, Chakraborty T, Eaton DC, Lucas R. Epithelial Sodium Channel-α Mediates the Protective Effect of the TNF-Derived TIP Peptide in Pneumolysin-Induced Endothelial Barrier Dysfunction. Front Immunol 2017; 8:842. [PMID: 28785264 PMCID: PMC5519615 DOI: 10.3389/fimmu.2017.00842] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/04/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is a major etiologic agent of bacterial pneumonia. Autolysis and antibiotic-mediated lysis of pneumococci induce release of the pore-forming toxin, pneumolysin (PLY), their major virulence factor, which is a prominent cause of acute lung injury. PLY inhibits alveolar liquid clearance and severely compromises alveolar-capillary barrier function, leading to permeability edema associated with pneumonia. As a consequence, alveolar flooding occurs, which can precipitate lethal hypoxemia by impairing gas exchange. The α subunit of the epithelial sodium channel (ENaC) is crucial for promoting Na+ reabsorption across Na+-transporting epithelia. However, it is not known if human lung microvascular endothelial cells (HL-MVEC) also express ENaC-α and whether this subunit is involved in the regulation of their barrier function. METHODS The presence of α, β, and γ subunits of ENaC and protein phosphorylation status in HL-MVEC were assessed in western blotting. The role of ENaC-α in monolayer resistance of HL-MVEC was examined by depletion of this subunit by specific siRNA and by employing the TNF-derived TIP peptide, a specific activator that directly binds to ENaC-α. RESULTS HL-MVEC express all three subunits of ENaC, as well as acid-sensing ion channel 1a (ASIC1a), which has the capacity to form hybrid non-selective cation channels with ENaC-α. Both TIP peptide, which specifically binds to ENaC-α, and the specific ASIC1a activator MitTx significantly strengthened barrier function in PLY-treated HL-MVEC. ENaC-α depletion significantly increased sensitivity to PLY-induced hyperpermeability and in addition, blunted the protective effect of both the TIP peptide and MitTx, indicating an important role for ENaC-α and for hybrid NSC channels in barrier function of HL-MVEC. TIP peptide blunted PLY-induced phosphorylation of both calmodulin-dependent kinase II (CaMKII) and of its substrate, the actin-binding protein filamin A (FLN-A), requiring the expression of both ENaC-α and ASIC1a. Since non-phosphorylated FLN-A promotes ENaC channel open probability and blunts stress fiber formation, modulation of this activity represents an attractive target for the protective actions of ENaC-α in both barrier function and liquid clearance. CONCLUSION Our results in cultured endothelial cells demonstrate a previously unrecognized role for ENaC-α in strengthening capillary barrier function that may apply to the human lung. Strategies aiming to activate endothelial NSC channels that contain ENaC-α should be further investigated as a novel approach to improve barrier function in the capillary endothelium during pneumonia.
Collapse
Affiliation(s)
- Istvan Czikora
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States.,Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, United States
| | - Supriya Sridhar
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Michael A Matthay
- Cardiovascular Research Institute, UCSF, San Francisco, CA, United States
| | - Helena Pillich
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Martina Hudel
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Besim Berisha
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Maritza J Romero
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Joyce Gonzales
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yuqing Huo
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Alexander D Verin
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - David Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| |
Collapse
|
8
|
Azzam ZS, Kinaneh S, Bahouth F, Ismael-Badarneh R, Khoury E, Abassi Z. Involvement of Cytokines in the Pathogenesis of Salt and Water Imbalance in Congestive Heart Failure. Front Immunol 2017; 8:716. [PMID: 28674538 PMCID: PMC5474564 DOI: 10.3389/fimmu.2017.00716] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/02/2017] [Indexed: 12/28/2022] Open
Abstract
Congestive heart failure (CHF) has become a major medical problem in the western world with high morbidity and mortality rates. CHF adversely affects several systems, mainly the kidneys and the lungs. While the involvement of the renin-angiotensin-aldosterone system and the sympathetic nervous system in the progression of cardiovascular, pulmonary, and renal dysfunction in experimental and clinical CHF is well established, the importance of pro-inflammatory mediators in the pathogenesis of this clinical setting is still evolving. In this context, CHF is associated with overexpression of pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1, and IL-6, which are activated in response to environmental injury. This family of cytokines has been implicated in the deterioration of CHF, where it plays an important role in initiating and integrating homeostatic responses both at the myocardium and circulatory levels. We and others showed that angiotensin II decreased the ability of the lungs to clear edema and enhanced the fibrosis process via phosphorylation of the mitogen-activated protein kinases p38 and p42/44, which are generally involved in cellular responses to pro-inflammatory cytokines. Literature data also indicate the involvement of these effectors in modulating ion channel activity. It has been reported that in heart failure due to mitral stenosis; there were varying degrees of vascular and other associated parenchymal changes such as edema and fibrosis. In this review, we will discuss the effects of cytokines and other inflammatory mediators on the kidneys and the lungs in heart failure; especially their role in renal and alveolar ion channels activity and fluid balance.
Collapse
Affiliation(s)
- Zaher S. Azzam
- Department of Physiology and Biophysics, Technion, Israel Institute of Technology, Haifa, Israel
- Internal Medicine “B”, Rambam Health Care Campus, Haifa, Israel
| | - Safa Kinaneh
- Department of Physiology and Biophysics, Technion, Israel Institute of Technology, Haifa, Israel
| | - Fadel Bahouth
- Department of Physiology and Biophysics, Technion, Israel Institute of Technology, Haifa, Israel
| | - Reem Ismael-Badarneh
- Department of Physiology and Biophysics, Technion, Israel Institute of Technology, Haifa, Israel
| | - Emad Khoury
- Department of Physiology and Biophysics, Technion, Israel Institute of Technology, Haifa, Israel
| | - Zaid Abassi
- Department of Physiology and Biophysics, Technion, Israel Institute of Technology, Haifa, Israel
| |
Collapse
|
9
|
Willam A, Aufy M, Tzotzos S, El-Malazi D, Poser F, Wagner A, Unterköfler B, Gurmani D, Martan D, Iqbal SM, Fischer B, Fischer H, Pietschmann H, Czikora I, Lucas R, Lemmens-Gruber R, Shabbir W. TNF Lectin-Like Domain Restores Epithelial Sodium Channel Function in Frameshift Mutants Associated with Pseudohypoaldosteronism Type 1B. Front Immunol 2017; 8:601. [PMID: 28611771 PMCID: PMC5447021 DOI: 10.3389/fimmu.2017.00601] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/08/2017] [Indexed: 11/28/2022] Open
Abstract
Previous in vitro studies have indicated that tumor necrosis factor (TNF) activates amiloride-sensitive epithelial sodium channel (ENaC) current through its lectin-like (TIP) domain, since cyclic peptides mimicking the TIP domain (e.g., solnatide), showed ENaC-activating properties. In the current study, the effects of TNF and solnatide on individual ENaC subunits or ENaC carrying mutated glycosylation sites in the α-ENaC subunit were compared, revealing a similar mode of action for TNF and solnatide and corroborating the previous assumption that the lectin-like domain of TNF is the relevant molecular structure for ENaC activation. Accordingly, TNF enhanced ENaC current by increasing open probability of the glycosylated channel, position N511 in the α-ENaC subunit being identified as the most important glycosylation site. TNF significantly increased Na+ current through ENaC comprising only the pore forming subunits α or δ, was less active in ENaC comprising only β-subunits, and showed no effect on ENaC comprising γ-subunits. TNF did not increase the membrane abundance of ENaC subunits to the extent observed with solnatide. Since the α-subunit is believed to play a prominent role in the ENaC current activating effect of TNF and TIP, we investigated whether TNF and solnatide can enhance αβγ-ENaC current in α-ENaC loss-of-function frameshift mutants. The efficacy of solnatide has been already proven in pathological conditions involving ENaC in phase II clinical trials. The frameshift mutations αI68fs, αT169fs, αP197fs, αE272fs, αF435fs, αR438fs, αY447fs, αR448fs, αS452fs, and αT482fs have been reported to cause pseudohypoaldosteronism type 1B (PHA1B), a rare, life-threatening, salt-wasting disease, which hitherto has been treated only symptomatically. In a heterologous expression system, all frameshift mutants showed significantly reduced amiloride-sensitive whole-cell current compared to wild type αβγ-ENaC, whereas membrane abundance varied between mutants. Solnatide restored function in α-ENaC frameshift mutants to current density levels of wild type ENaC or higher despite their lacking a binding site for solnatide, previously located to the region between TM2 and the C-terminus of the α-subunit. TNF similarly restored current density to wild type levels in the mutant αR448fs. Activation of βγ-ENaC may contribute to this moderate current enhancement, but whatever the mechanism, experimental data indicate that solnatide could be a new strategy to treat PHA1B.
Collapse
Affiliation(s)
- Anita Willam
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria.,APEPTICO GmbH, Vienna, Austria
| | - Mohammed Aufy
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | | | - Dina El-Malazi
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Franziska Poser
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Alina Wagner
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Birgit Unterköfler
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Didja Gurmani
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - David Martan
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | | | | | | | | | - Istvan Czikora
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Rosa Lemmens-Gruber
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Waheed Shabbir
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria.,APEPTICO GmbH, Vienna, Austria
| |
Collapse
|
10
|
Peteranderl C, Sznajder JI, Herold S, Lecuona E. Inflammatory Responses Regulating Alveolar Ion Transport during Pulmonary Infections. Front Immunol 2017; 8:446. [PMID: 28458673 PMCID: PMC5394420 DOI: 10.3389/fimmu.2017.00446] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 03/31/2017] [Indexed: 01/13/2023] Open
Abstract
The respiratory epithelium is lined by a tightly balanced fluid layer that allows normal O2 and CO2 exchange and maintains surface tension and host defense. To maintain alveolar fluid homeostasis, both the integrity of the alveolar–capillary barrier and the expression of epithelial ion channels and pumps are necessary to establish a vectorial ion gradient. However, during pulmonary infection, auto- and/or paracrine-acting mediators induce pathophysiological changes of the alveolar–capillary barrier, altered expression of epithelial Na,K-ATPase and of epithelial ion channels including epithelial sodium channel and cystic fibrosis membrane conductance regulator, leading to the accumulation of edema and impaired alveolar fluid clearance. These mediators include classical pro-inflammatory cytokines such as TGF-β, TNF-α, interferons, or IL-1β that are released upon bacterial challenge with Streptococcus pneumoniae, Klebsiella pneumoniae, or Mycoplasma pneumoniae as well as in viral infection with influenza A virus, pathogenic coronaviruses, or respiratory syncytial virus. Moreover, the pro-apoptotic mediator TNF-related apoptosis-inducing ligand, extracellular nucleotides, or reactive oxygen species impair epithelial ion channel expression and function. Interestingly, during bacterial infection, alterations of ion transport function may serve as an additional feedback loop on the respiratory inflammatory profile, further aggravating disease progression. These changes lead to edema formation and impair edema clearance which results in suboptimal gas exchange causing hypoxemia and hypercapnia. Recent preclinical studies suggest that modulation of the alveolar–capillary fluid homeostasis could represent novel therapeutic approaches to improve outcomes in infection-induced lung injury.
Collapse
Affiliation(s)
- Christin Peteranderl
- Department of Internal Medicine II, University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Susanne Herold
- Department of Internal Medicine II, University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Emilia Lecuona
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| |
Collapse
|
11
|
Hartmann EK, Ziebart A, Thomas R, Liu T, Schad A, Tews M, Moosmann B, Kamuf J, Duenges B, Thal SC, David M. Inhalation therapy with the synthetic TIP-like peptide AP318 attenuates pulmonary inflammation in a porcine sepsis model. BMC Pulm Med 2015; 15:7. [PMID: 25879802 PMCID: PMC4346123 DOI: 10.1186/s12890-015-0002-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 01/19/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The lectin-like domain of TNF-α can be mimicked by synthetic TIP peptides and represents an innovative pharmacologic option to treat edematous respiratory failure. TIP inhalation was shown to reduce pulmonary edema and improve gas exchange. In addition to its edema resolution effect, TIP peptides may exert some anti-inflammatory properties. The present study therefore investigates the influence of the inhaled TIP peptide AP318 on intrapulmonary inflammatory response in a porcine model of systemic sepsis. METHODS In a randomized-blinded setting lung injury was induced in 18 pigs by lipopolysaccharide-infusion and a second hit with a short period of ventilator-induced lung stress, followed by a six-hour observation period. The animals received either two inhalations with the peptide (AP318, 2×1 mg kg(-1)) or vehicle. Post-mortem pulmonary expression of inflammatory and mechanotransduction markers were determined by real-time polymerase chain reaction (IL-1β, IL-6, TNF-α, COX-2, iNOS, amphiregulin, and tenascin-c). Furthermore, regional histopathological lung injury, edema formation and systemic inflammation were quantified. RESULTS Despite similar systemic response to lipopolysaccharide infusion in both groups, pulmonary inflammation (IL-6, TNF-α, COX-2, tenascin-c) was significantly mitigated by AP318. Furthermore, a Western blot analysis shows a significantly lower of COX-2 protein level. The present sepsis model caused minor lung edema formation and moderate gas exchange impairment. Six hours after onset pathologic scoring showed no improvement, while gas exchange parameters and pulmonary edema formation were similar in the two groups. CONCLUSION In summary, AP318 significantly attenuated intrapulmonary inflammatory response even without the presence or resolution of severe pulmonary edema in a porcine model of systemic sepsis-associated lung injury. These findings suggest an anti-inflammatory mechanism of the lectin-like domain beyond mere edema reabsorption in endotoxemic lung injury in vivo.
Collapse
Affiliation(s)
- Erik K Hartmann
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Alexander Ziebart
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Rainer Thomas
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Tanghua Liu
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Arno Schad
- Institute of Pathology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Martha Tews
- Institute of Pathobiochemistry, Medical Center of the Johannes, Gutenberg-University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Bernd Moosmann
- Institute of Pathobiochemistry, Medical Center of the Johannes, Gutenberg-University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Jens Kamuf
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Bastian Duenges
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Serge C Thal
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| | - Matthias David
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Langenbeckstrasse 1, 55131, Mainz, Germany.
| |
Collapse
|
12
|
Czikora I, Alli A, Bao HF, Kaftan D, Sridhar S, Apell HJ, Gorshkov B, White R, Zimmermann A, Wendel A, Pauly-Evers M, Hamacher J, Garcia-Gabay I, Fischer B, Verin A, Bagi Z, Pittet JF, Shabbir W, Lemmens-Gruber R, Chakraborty T, Lazrak A, Matthay MA, Eaton DC, Lucas R. A novel tumor necrosis factor-mediated mechanism of direct epithelial sodium channel activation. Am J Respir Crit Care Med 2014; 190:522-32. [PMID: 25029038 DOI: 10.1164/rccm.201405-0833oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
RATIONALE Alveolar liquid clearance is regulated by Na(+) uptake through the apically expressed epithelial sodium channel (ENaC) and basolaterally localized Na(+)-K(+)-ATPase in type II alveolar epithelial cells. Dysfunction of these Na(+) transporters during pulmonary inflammation can contribute to pulmonary edema. OBJECTIVES In this study, we sought to determine the precise mechanism by which the TIP peptide, mimicking the lectin-like domain of tumor necrosis factor (TNF), stimulates Na(+) uptake in a homologous cell system in the presence or absence of the bacterial toxin pneumolysin (PLY). METHODS We used a combined biochemical, electrophysiological, and molecular biological in vitro approach and assessed the physiological relevance of the lectin-like domain of TNF in alveolar liquid clearance in vivo by generating triple-mutant TNF knock-in mice that express a mutant TNF with deficient Na(+) uptake stimulatory activity. MEASUREMENTS AND MAIN RESULTS TIP peptide directly activates ENaC, but not the Na(+)-K(+)-ATPase, upon binding to the carboxy-terminal domain of the α subunit of the channel. In the presence of PLY, a mediator of pneumococcal-induced pulmonary edema, this binding stabilizes the ENaC-PIP2-MARCKS complex, which is necessary for the open probability conformation of the channel and preserves ENaC-α protein expression, by means of blunting the protein kinase C-α pathway. Triple-mutant TNF knock-in mice are more prone than wild-type mice to develop edema with low-dose intratracheal PLY, correlating with reduced pulmonary ENaC-α subunit expression. CONCLUSIONS These results demonstrate a novel TNF-mediated mechanism of direct ENaC activation and indicate a physiological role for the lectin-like domain of TNF in the resolution of alveolar edema during inflammation.
Collapse
|
13
|
van den Berg E, Bem RA, Bos AP, Lutter R, van Woensel JBM. The effect of TIP on pneumovirus-induced pulmonary edema in mice. PLoS One 2014; 9:e102749. [PMID: 25047452 PMCID: PMC4105480 DOI: 10.1371/journal.pone.0102749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 06/20/2014] [Indexed: 01/14/2023] Open
Abstract
Background Pulmonary edema plays a pivotal role in the pathophysiology of respiratory syncytial virus (RSV)-induced respiratory failure. In this study we determined whether treatment with TIP (AP301), a synthetic cyclic peptide that mimics the lectin-like domain of human TNF, decreases pulmonary edema in a mouse model of severe human RSV infection. TIP is currently undergoing clinical trials as a therapy for pulmonary permeability edema and has been shown to decrease pulmonary edema in different lung injury models. Methods C57BL/6 mice were infected with pneumonia virus of mice (PVM) and received TIP or saline (control group) by intratracheal instillation on day five (early administration) or day seven (late administration) after infection. In a separate set of experiments the effect of multiple dose administration of TIP versus saline was tested. Pulmonary edema was determined by the lung wet-to-dry (W/D) weight ratio and was assessed at different time-points after the administration of TIP. Secondary outcomes included clinical scores and lung cellular response. Results TIP did not have an effect on pulmonary edema in different dose regimens at different time points during PVM infection. In addition, TIP administration did not affect clinical severity scores or lung cellular response. Conclusion In this murine model of severe RSV infection TIP did not affect pulmonary edema nor course of disease.
Collapse
Affiliation(s)
- Elske van den Berg
- Pediatric Intensive Care Unit, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands
- * E-mail:
| | - Reinout A. Bem
- Pediatric Intensive Care Unit, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands
| | - Albert P. Bos
- Pediatric Intensive Care Unit, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands
| | - Rene Lutter
- Department of Respiratory Medicine and Experimental Immunology, Academic Medical Center, Amsterdam, The Netherlands
| | - Job B. M. van Woensel
- Pediatric Intensive Care Unit, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
14
|
Hartmann EK, Thomas R, Liu T, Stefaniak J, Ziebart A, Duenges B, Eckle D, Markstaller K, David M. TIP peptide inhalation in experimental acute lung injury: effect of repetitive dosage and different synthetic variants. BMC Anesthesiol 2014; 14:42. [PMID: 24904234 PMCID: PMC4046002 DOI: 10.1186/1471-2253-14-42] [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] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 05/21/2014] [Indexed: 12/17/2022] Open
Abstract
Background Inhalation of TIP peptides that mimic the lectin-like domain of TNF-α is a novel approach to attenuate pulmonary oedema on the threshold to clinical application. A placebo-controlled porcine model of acute respiratory distress syndrome (ARDS) demonstrated a reduced thermodilution-derived extravascular lung water index (EVLWI) and improved gas exchange through TIP peptide inhalation within three hours. Based on these findings, the present study compares a single versus a repetitive inhalation of a TIP peptide (TIP-A) and two alternate peptide versions (TIP-A, TIP-B). Methods Following animal care committee approval ARDS was induced by bronchoalveolar lavage followed by injurious ventilation in 21 anaesthetized pigs. A randomised-blinded three-group setting compared the single-dosed peptide variants TIP-A and TIP-B as well as single versus repetitive inhalation of TIP-A (n = 7 per group). Over two three-hour intervals parameters of gas exchange, transpulmonary thermodilution, calculated alveolar fluid clearance, and ventilation/perfusion-distribution were assessed. Post-mortem measurements included pulmonary wet/dry ratio and haemorrhage/congestion scoring. Results The repetitive TIP-A inhalation led to a significantly lower wet/dry ratio than a single dose and a small but significantly lower EVLWI. However, EVLWI changes over time and the derived alveolar fluid clearance did not differ significantly. The comparison of TIP-A and B showed no relevant differences. Gas exchange and ventilation/perfusion-distribution significantly improved in all groups without intergroup differences. No differences were found in haemorrhage/congestion scoring. Conclusions In comparison to a single application the repetitive inhalation of a TIP peptide in three-hour intervals may lead to a small additional reduction the lung water content. Two alternate TIP peptide versions showed interchangeable characteristics.
Collapse
Affiliation(s)
- Erik K Hartmann
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| | - Rainer Thomas
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| | - Tanghua Liu
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| | - Joanna Stefaniak
- Department of Anaesthesiology, General Critical Care Medicine and Pain Therapy, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Alexander Ziebart
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| | - Bastian Duenges
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| | - Daniel Eckle
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| | - Klaus Markstaller
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany ; Department of Anaesthesiology, General Critical Care Medicine and Pain Therapy, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Matthias David
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
| |
Collapse
|
15
|
Schwameis R, Eder S, Pietschmann H, Fischer B, Mascher H, Tzotzos S, Fischer H, Lucas R, Zeitlinger M, Hermann R. A FIM study to assess safety and exposure of inhaled single doses of AP301-A specific ENaC channel activator for the treatment of acute lung injury. J Clin Pharmacol 2014; 54:341-50. [PMID: 24515273 PMCID: PMC4160070 DOI: 10.1002/jcph.203] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/01/2013] [Indexed: 11/05/2022]
Abstract
AP301 is an activator of ENaC-mediated Na(+) uptake for the treatment of pulmonary permeability edema in acute respiratory distress syndrome (ARDS). The purpose of this "first-in-man" study was to examine local and systemic safety and systemic exposure of ascending single doses of AP301, when inhaled by healthy male subjects. In a double-blind, placebo-controlled study, 48 healthy male subjects were randomized to 6 ascending dose groups (single doses up to 120 mg) of 8 subjects each (3:1 randomization of AP301: placebo). Serial assessments included spirometry, exhaled nitric oxide (eNO), vital signs, ECG, safety laboratory, adverse events (AE), and blood samples for the quantification of AP301 in plasma. Descriptive statistics was applied. All 48 subjects received treatment, and completed the study as per protocol. No serious, local (e.g., hoarseness, cough, bronchospasm), or dose-limiting AEs were noted. None of the assessments indicated notable dose or time-related alterations of safety outcomes. Observed AP301 systemic exposure levels were very low, with mean Cmax values of <2.5 ng/mL in the highest dose groups. Inhaled AP301 single doses up to 120 mg were safe and well tolerated by healthy male subjects. Distribution of inhaled AP301 was largely confined to the lung, as indicated by very low AP301 systemic exposure levels.
Collapse
Affiliation(s)
- Richard Schwameis
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Sandra Eder
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | | | | | | | | | | | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Vascular Biology Center, Georgia Health Sciences University, Augusta, GA, USA
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Robert Hermann
- Clinical Research Appliance, Heinrich-Vingerhut-Weg 3, D-63571, Gelnhausen, Germany
| |
Collapse
|
16
|
Hartmann EK, Bentley A, Duenges B, Klein KU, Boehme S, Markstaller K, David M. TIP peptide inhalation in oleic acid-induced experimental lung injury: a post-hoc comparison. BMC Res Notes 2013; 6:385. [PMID: 24070340 PMCID: PMC3849219 DOI: 10.1186/1756-0500-6-385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/25/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The lectin-like domain of TNF-α mimicked by an inhaled TIP peptide represents a novel approach to attenuate a pulmonary edema in respiratory failure, which is on the threshold to clinical application. In extension to a previously published study, which reported an improved pulmonary function following TIP peptide inhalation in a porcine model of lavage-induced lung injury, a post-hoc comparison to additional experiments was conducted. This analysis addresses the hypothesis that oleic acid injection-induced capillary leakage and alveolar necrosis blunts the previously reported beneficial effects of TIP peptide inhalation in a porcine model. FINDINGS Following animal care committee approval lung injury was induced by oleic acid injection in six pigs with a setting strictly according to a previously published protocol that was used for lung-lavaged pigs. Ventilation/perfusion-distribution by multiple inert gas elimination, parameters of gas exchange and pulmonary edema were assessed as surrogates of the pulmonary function. A significantly improved ventilation/perfusion-distribution following TIP inhalation was recognized only in the bronchoalveolar lavage model but not following oleic acid injection. The time course after oleic acid injection yielded no comparable impact of the TIP peptide on gas exchange and edema formation. CONCLUSIONS Reported beneficial effects of the TIP peptide on gas exchange and pulmonary edema were not reproducible in the oleic acid injection model. This analysis assumes that sustained alveolar epithelial necrosis as induced by oleic acid injection may inhibit the TIP-induced edema resolution. Regarding the on-going clinical development of the TIP peptide this approach should hardly be effective in states of severe alveolar epithelial damage.
Collapse
Affiliation(s)
- Erik K Hartmann
- Department of Anaesthesiology, Medical Centre of the Johannes Gutenberg-University, Langenbeckstr, 1, 55131 Mainz, Germany.
| | | | | | | | | | | | | |
Collapse
|
17
|
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).
Collapse
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.)
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Grzesik BA, Vohwinkel CU, Morty RE, Mayer K, Herold S, Seeger W, Vadász I. Efficient gene delivery to primary alveolar epithelial cells by nucleofection. Am J Physiol Lung Cell Mol Physiol 2013; 305:L786-94. [PMID: 24077946 DOI: 10.1152/ajplung.00191.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Primary alveolar epithelial cells play a pivotal role in lung research, particularly when focusing on gas exchange, barrier function, and transepithelial transport processes. However, efficient transfection of primary alveolar epithelial cells continues to be a major challenge. In the present study, we applied nucleofection, a novel method of gene and oligonucleotide delivery to the nucleus of cells by electroporation, to achieve highly efficient transfection of primary alveolar epithelial type II (ATII) cells. To quantify the amount of ATII cells effectively transfected, we applied a plasmid expressing GFP and assessed the amount of GFP-expressing cells by flow cytometry. Analysis of the nucleofected ATII cells revealed a concentration-dependent transfection efficiency of up to 50% when using 3-8 μg plasmid DNA without affecting cell viability. Nucleofection of cultured A549 and H441 cells yielded similar transfection rates. Importantly, nucleofection of ATII cells did not interfere with the integrity of ATII monolayers even with use of relatively high concentrations of plasmid DNA. In subsequent studies, we also efficiently delivered small interfering RNAs to ATII cells by nucleofection, thereby silencing Akt and the multiligand receptor megalin, which has been recently shown to play a key role in removal of excess protein from the alveolar space, and effectively inhibited megalin-driven uptake and transcellular transport of albumin in ATII cells. Thus we report successful transfection of primary rat alveolar epithelial cells with both plasmids and oligonucleotides via nucleofection with high viability and consistently good transfection rates without impairing key physiological properties of the cells.
Collapse
Affiliation(s)
- Benno A Grzesik
- Dept. of Internal Medicine, Justus Liebig Univ., Universities of Giessen and Marburg Lung Center, Klinikstrasse 33, 35392 Giessen, Germany.
| | | | | | | | | | | | | |
Collapse
|
19
|
Mini-review: novel therapeutic strategies to blunt actions of pneumolysin in the lungs. Toxins (Basel) 2013; 5:1244-60. [PMID: 23860351 PMCID: PMC3737495 DOI: 10.3390/toxins5071244] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 06/25/2013] [Accepted: 06/27/2013] [Indexed: 01/11/2023] Open
Abstract
Severe pneumonia is the main single cause of death worldwide in children under five years of age. The main etiological agent of pneumonia is the G+ bacterium Streptococcus pneumoniae, which accounts for up to 45% of all cases. Intriguingly, patients can still die days after commencing antibiotic treatment due to the development of permeability edema, although the pathogen was successfully cleared from their lungs. This condition is characterized by a dramatically impaired alveolar epithelial-capillary barrier function and a dysfunction of the sodium transporters required for edema reabsorption, including the apically expressed epithelial sodium channel (ENaC) and the basolaterally expressed sodium potassium pump (Na+-K+-ATPase). The main agent inducing this edema formation is the virulence factor pneumolysin, a cholesterol-binding pore-forming toxin, released in the alveolar compartment of the lungs when pneumococci are being lysed by antibiotic treatment or upon autolysis. Sub-lytic concentrations of pneumolysin can cause endothelial barrier dysfunction and can impair ENaC-mediated sodium uptake in type II alveolar epithelial cells. These events significantly contribute to the formation of permeability edema, for which currently no standard therapy is available. This review focuses on discussing some recent developments in the search for the novel therapeutic agents able to improve lung function despite the presence of pore-forming toxins. Such treatments could reduce the potentially lethal complications occurring after antibiotic treatment of patients with severe pneumonia.
Collapse
|
20
|
Dulebo A, Ettrich R, Lucas R, Kaftan D. A computational study of the oligosaccharide binding sites in the lectin-like domain of Tumor Necrosis Factor and the TNF-derived TIP peptide. Curr Pharm Des 2013; 18:4236-43. [PMID: 22697478 DOI: 10.2174/138161212802430549] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 06/11/2012] [Indexed: 01/18/2023]
Abstract
The lectin-like domain of Tumor Necrosis Factor (TNF), mimicked by the TIP peptide, activates amiloride-sensitive sodium uptake in type II alveolar epithelial cells and as such increases alveolar liquid clearance in dysfunctional lungs. This protective effect is blunted upon mutation of residues T105, E107 and E110 in human TNF into alanine or upon pre-incubation of the cytokine with the disaccharide N,N'-diacetylchitobiose. In this study, we used molecular docking and molecular dynamics simulation to predict the binding sites for N,N'-diacetylchitobiose and trimannose-O-ethyl in the lectin-like domain of TNF and in the TIP peptide. Specific sites (K98, S99, P100, Q102 and E116) in the three loops of the lectin-like domain provide specific binding for both oligosaccharides, but none of the residues crucial for anti-edema activity are involved in hydrogen bonding with oligosaccharides or are subjected to steric hindrance by them. These results thus suggest that neither chitobiose nor trimannose affect crucial amino acids, while they occupy the cavity in the lectin-like domain. Consequently, both crucial amino acids and the emptiness of the cavity in the lectin-like domain may be critical for TNF's lectin-like activity. Analogously, the R4, E5, P7, Y16 amino acids of the TIP peptide are involved in forming hydrogen bonds with both oligosaccharides, whereas residues T6, E8 and E11 (corresponding to T105, E107 and E110 in hTNF) play an important role in stabilizing the peptide-oligosaccharide complex, supporting the hypothesis that amino acids in the polar region (TPEGAE) of the TIP peptide represent only a partial binding motif for sugars.
Collapse
Affiliation(s)
- Alexander Dulebo
- University of South Bohemia in Ceské Budejovice, Faculty of Science, Czech Republic
| | | | | | | |
Collapse
|
21
|
HARTMANN EK, BOEHME S, DUENGES B, BENTLEY A, KLEIN KU, KWIECIEN R, SHI C, SZCZYRBA M, DAVID M, MARKSTALLER K. An inhaled tumor necrosis factor-alpha-derived TIP peptide improves the pulmonary function in experimental lung injury. Acta Anaesthesiol Scand 2013; 57:334-41. [PMID: 23216436 DOI: 10.1111/aas.12034] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2012] [Indexed: 01/11/2023]
Abstract
INTRODUCTION The lectin-like domain of TNF-α enhances the fluid clearance across the alveolar barrier. For experimental purposes, the lectin-like domain can be mimicked by a synthetic peptide representing the TIP-motif of TNF-α. The present study aims to assess the acute effect of TIP on the pulmonary function in a porcine model of acute respiratory distress syndrome (ARDS). METHODS Lung injury was induced in 16 pigs (25-27 kg) by bronchoalveolar lavage followed by injurious ventilation. Following randomisation, either nebulised TIP (1 mg/kg; AP301, APEPTICO, Vienna, Austria) or water for injection (control group) was administered. During 5 h of monitoring, the extravascular lung water index (EVLWI), the quotient of partial pressure of oxygen and inspired oxygen concentration (PaO(2) /FiO(2) ) and the pulmonary shunt fraction were repetitively assessed. The data were evaluated by an analysis of variance including Bonferroni-Holm correction. RESULTS Comparable baseline conditions in both groups were achieved. Ventilatory parameters were standardised in both groups. In the TIP group, a significant reduction of the EVLWI and a simultaneous increase in the PaO(2) /FiO(2) ratio was shown (each P < 0.0001). No changes in the control group were observed (EVLWI: P = 0.43, PaO(2) /FiO(2) : P = 0.60). The intergroup comparison demonstrates a significant advantage of TIP inhalation over placebo (EVLWI: P < 0.0001, PaO(2) /FiO(2) : P = 0.004, shunt fraction: P = 0.0005). CONCLUSIONS The inhalation of TIP induces an amelioration of clinical surrogate parameters of the lung function in a porcine lung injury model. By mimicking the lectin-like domain, the synthetic TIP peptide AP301 is an innovative approach as supportive therapy in ARDS.
Collapse
Affiliation(s)
- E. K. HARTMANN
- Department of Anaesthesiology; Medical Center of the Johannes Gutenberg-University; Mainz; Germany
| | | | - B. DUENGES
- Department of Anaesthesiology; Medical Center of the Johannes Gutenberg-University; Mainz; Germany
| | - A. BENTLEY
- Department of Anaesthesiology; Medical Center of the Johannes Gutenberg-University; Mainz; Germany
| | | | | | | | - M. SZCZYRBA
- Department of Anaesthesiology; Medical Center of the Johannes Gutenberg-University; Mainz; Germany
| | - M. DAVID
- Department of Anaesthesiology; Medical Center of the Johannes Gutenberg-University; Mainz; Germany
| | | |
Collapse
|
22
|
Tzotzos S, Fischer B, Fischer H, Pietschmann H, Lucas R, Dupré G, Lemmens-Gruber R, Hazemi P, Prymaka V, Shabbir W. AP301, a synthetic peptide mimicking the lectin-like domain of TNF, enhances amiloride-sensitive Na(+) current in primary dog, pig and rat alveolar type II cells. Pulm Pharmacol Ther 2013; 26:356-63. [PMID: 23313096 DOI: 10.1016/j.pupt.2012.12.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 12/11/2012] [Accepted: 12/31/2012] [Indexed: 01/11/2023]
Abstract
Pulmonary permeability oedema is a frequent complication in a number of life-threatening lung conditions, such as ALI and ARDS. Apart from ventilation strategies, no specific therapy yet exists for treatment of these potentially fatal illnesses. The oedema-reducing capacity of the lectin-like domain of TNF (TIP) and of synthetic peptides, mTIP and hTIP, which mimic the TIP domain of mouse and human TNF, have been demonstrated in various studies in rodents. Cell-based electrophysiological studies have revealed that the alveolar fluid clearing capacity of TNF and the TIP peptides is due to activation of the amiloride-sensitive Na(+) current in alveolar epithelial cells and that the primary site of action is on the apical side of these cells. AP301, a synthetic cyclic peptide mimicking the TIP domain of human TNF is currently undergoing clinical trials as a therapy for pulmonary permeability oedema. AP301 has been shown to improve alveolar liquid clearance and lung function in a porcine model of ALI. For non-clinical regulatory assessment, dog, pig and rat are standard animal models; accordingly, pre-clinical toxicological and pharmacological safety studies have been conducted with AP301 in dogs and rats. Hitherto, no studies have assessed the pharmacodynamic effect of AP301 on primary canine or porcine type II AEC. The current study describes the effect of AP301 on the amiloride-sensitive Na(+) current in type II AEC isolated from dog, pig and rat lungs. In whole cell patch clamp experiments with dog type II AEC, an increase in the amiloride-sensitive Na(+) current from 3.7 pA to 49.4 pA was observed in the presence of AP301; in pig type II AEC, an increase from 10.0 pA to 159.6 pA was observed, and in rat AEC, from 6.9 pA to 62.4 pA. In whole cell patch clamp experiments in A549 cells, AP301-induced enhancement of the amiloride-sensitive current was eliminated when Na(+) in the bath solution was replaced with N-methyl-d-glucamine (NMDG), and when the cells were pre-incubated with 5-aminoimidazole-4-carboxamide-1-ß-d-ribofuranoside (AICAR), an inhibitor of ENaC, but enhancement was unaffected by addition of cyclic nucleotide-gated (CNG) channel inhibitors Zn(2+) or l-cis-diltiazem prior to AP301. These results provide strong evidence that AP301 activates the amiloride-sensitive Na(+) current through ENaC in type II AEC from dog, pig and rat. To our knowledge, this is the first cell-based analysis of the oedema-clearing effect of AP301 observed in the porcine model of pulmonary oedema. Furthermore, the results validate the dog and pig models in non-clinical assessment of AP301.
Collapse
Affiliation(s)
- Susan Tzotzos
- Apeptico Research and Development GmbH, Mariahilferstrasse 136, 1150 Vienna, Austria.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Buchäckert Y, Rummel S, Vohwinkel CU, Gabrielli NM, Grzesik BA, Mayer K, Herold S, Morty RE, Seeger W, Vadász I. Megalin mediates transepithelial albumin clearance from the alveolar space of intact rabbit lungs. J Physiol 2012; 590:5167-81. [PMID: 22826129 DOI: 10.1113/jphysiol.2012.233403] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The alveolo-capillary barrier is effectively impermeable to large solutes such as proteins. A hallmark of acute lung injury/acute respiratory distress syndrome is the accumulation of protein-rich oedema fluid in the distal airspaces. Excess protein must be cleared from the alveolar space for recovery; however, the mechanisms of protein clearance remain incompletely understood. In intact rabbit lungs 29.8 ± 2.2% of the radio-labelled alveolar albumin was transported to the vascular compartment at 37°C within 120 min, as assessed by real-time measurement of 125I-albumin clearance from the alveolar space. At 4°C or 22°C significantly lower albumin clearance (3.7 ± 0.4 or 16.2 ± 1.1%, respectively) was observed. Deposition of a 1000-fold molar excess of unlabelled albumin into the alveolar space or inhibition of cytoskeletal rearrangement or clathrin-dependent endocytosis largely inhibited the transport of 125I-albumin to the vasculature, while administration of unlabelled albumin to the vascular space had no effect on albumin clearance. Furthermore, albumin uptake capacity was measured as about 0.37 mg ml−1 in cultured rat lung epithelial monolayers, further highlighting the (patho)physiological relevance of active alveolar epithelial protein transport. Moreover, gene silencing and pharmacological inhibition of the multi-ligand receptor megalin resulted in significantly decreased albumin binding and uptake in monolayers of primary alveolar type II and type I-like and cultured lung epithelial cells. Our data indicate that clearance of albumin from the distal air spaces is facilitated by an active, high-capacity, megalin-mediated transport process across the alveolar epithelium. Further understanding of this mechanism is of clinical importance, since an inability to clear excess protein from the alveolar space is associated with poor outcome in patients with acute lung injury/acute respiratory distress syndrome.
Collapse
Affiliation(s)
- Yasmin Buchäckert
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, Klinikstrasse 33, 35392 Giessen, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Lucas R, Yang G, Gorshkov BA, Zemskov EA, Sridhar S, Umapathy NS, Jezierska-Drutel A, Alieva IB, Leustik M, Hossain H, Fischer B, Catravas JD, Verin AD, Pittet JF, Caldwell RB, Mitchell TJ, Cederbaum SD, Fulton DJ, Matthay MA, Caldwell RW, Romero MJ, Chakraborty T. Protein kinase C-α and arginase I mediate pneumolysin-induced pulmonary endothelial hyperpermeability. Am J Respir Cell Mol Biol 2012; 47:445-53. [PMID: 22582175 DOI: 10.1165/rcmb.2011-0332oc] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Antibiotics-induced release of the pore-forming virulence factor pneumolysin (PLY) in patients with pneumococcal pneumonia results in its presence days after lungs are sterile and is a major factor responsible for the induction of permeability edema. Here we sought to identify major mechanisms mediating PLY-induced endothelial dysfunction. We evaluated PLY-induced endothelial hyperpermeability in human lung microvascular endothelial cells (HL-MVECs) and human lung pulmonary artery endothelial cells in vitro and in mice instilled intratracheally with PLY. PLY increases permeability in endothelial monolayers by reducing stable and dynamic microtubule content and modulating VE-cadherin expression. These events, dependent upon an increased calcium influx, are preceded by protein kinase C (PKC)-α activation, perturbation of the RhoA/Rac1 balance, and an increase in myosin light chain phosphorylation. At later time points, PLY treatment increases the expression and activity of arginase in HL-MVECs. Arginase inhibition abrogates and suppresses PLY-induced endothelial barrier dysfunction by restoring NO generation. Consequently, a specific PKC-α inhibitor and the TNF-derived tonoplast intrinsic protein peptide, which blunts PLY-induced PKC-α activation, are able to prevent activation of arginase in HL-MVECs and to reduce PLY-induced endothelial hyperpermeability in mice. Arginase I (AI)(+/-)/arginase II (AII)(-/-) C57BL/6 mice, displaying a significantly reduced arginase I expression in the lungs, are significantly less sensitive to PLY-induced capillary leak than their wild-type or AI(+/+)/AII(-/-) counterparts, indicating an important role for arginase I in PLY-induced endothelial hyperpermeability. These results identify PKC-α and arginase I as potential upstream and downstream therapeutic targets in PLY-induced pulmonary endothelial dysfunction.
Collapse
Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center and Dept. of Pharmacology and Toxicology, Georgia Health Sciences University, 1459 Laney-Walker Blvd., Augusta, GA 30912-2500, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Vadász I, Weiss CH, Sznajder JI. Ubiquitination and proteolysis in acute lung injury. Chest 2012; 141:763-771. [PMID: 22396561 DOI: 10.1378/chest.11-1660] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Ubiquitination is a posttranslational modification that regulates a variety of cellular functions depending on timing, subcellular localization, and type of tagging, as well as modulators of ubiquitin binding leading to proteasomal or lysosomal degradation or nonproteolytic modifications. Ubiquitination plays an important role in the pathogenesis of acute lung injury (ALI) and other lung diseases with pathologies secondary to inflammation, mechanical ventilation, and decreased physical mobility. Particularly, ubiquitination has been shown to affect alveolar epithelial barrier function and alveolar edema clearance by targeting the Na,K-ATPase and epithelial Na(+) channels upon lung injury. Notably, the proteasomal system also exhibits distinct functions in the extracellular space, which may contribute to the pathogenesis of ALI and other pulmonary diseases. Better understanding of these mechanisms may ultimately lead to novel therapeutic modalities by targeting elements of the ubiquitination pathway.
Collapse
Affiliation(s)
- István Vadász
- Department of Internal Medicine, University of Giessen Lung Center, Justus Liebig University, Giessen, Germany.
| | - Curtis H Weiss
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL
| |
Collapse
|
26
|
Liu H, Dai L, Hao Z, Huang W, Yang Q. Hydrophobic cavity in C-terminus is essential for hTNF-α trimer conformation. Biochimie 2012; 94:1001-8. [DOI: 10.1016/j.biochi.2011.12.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 12/19/2011] [Indexed: 10/14/2022]
|
27
|
Yang G, Hamacher J, Gorshkov B, White R, Sridhar S, Verin A, Chakraborty T, Lucas R. The Dual Role of TNF in Pulmonary Edema. J Cardiovasc Dis Res 2011; 1:29-36. [PMID: 21188088 PMCID: PMC3004168 DOI: 10.4103/0975-3583.59983] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
—Pulmonary edema, a major manifestation of left ventricular heart failure, renal insufficiency, shock, diffuse alveolar damage and lung hypersensitivity states, is a significant medical problem worldwide and can be life-threatening. The proinflammatory cytokine tumor necrosis factor (TNF) has been shown to contribute to the pathogenesis and development of pulmonary edema. However, some recent studies have demonstrated surprisingly that TNF can also promote alveolar fluid reabsorption in vivo and in vitro. This protective effect of the cytokine is mediated by the lectin-like domain of the cytokine, which is spatially distinct from the TNF receptor binding sites. The TIP peptide, a synthetic mimic of the lectin-like domain of TNF, can significantly increase alveolar fluid clearance and improve lung compliance in pulmonary edema models. In this review, we will discuss the dual role of TNF in pulmonary edema.
Collapse
Affiliation(s)
- Guang Yang
- Vascular Biology Center & Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA, 30912, USA
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Ion channels in inflammation. Pflugers Arch 2011; 461:401-21. [PMID: 21279380 DOI: 10.1007/s00424-010-0917-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 12/19/2010] [Accepted: 12/19/2010] [Indexed: 12/12/2022]
Abstract
Most physical illness in vertebrates involves inflammation. Inflammation causes disease by fluid shifts across cell membranes and cell layers, changes in muscle function and generation of pain. These disease processes can be explained by changes in numbers or function of ion channels. Changes in ion channels have been detected in diarrhoeal illnesses, pyelonephritis, allergy, acute lung injury and systemic inflammatory response syndromes involving septic shock. The key role played by changes in ion transport is directly evident in inflammation-induced pain. Expression or function of all major categories of ion channels like sodium, chloride, calcium, potassium, transient receptor potential, purinergic receptor and acid-sensing ion channels can be influenced by cyto- and chemokines, prostaglandins, leukotrienes, histamine, ATP, reactive oxygen species and protons released in inflammation. Key pathways in this interaction are cyclic nucleotide, phosphoinositide and mitogen-activated protein kinase-mediated signalling, direct modification by reactive oxygen species like nitric oxide, ATP or protons and disruption of the cytoskeleton. Therapeutic interventions to modulate the adverse and overlapping effects of the numerous different inflammatory mediators on each ion transport system need to target adversely affected ion transport systems directly and locally.
Collapse
|
29
|
Hazemi P, Tzotzos SJ, Fischer B, Andavan GSB, Fischer H, Pietschmann H, Lucas R, Lemmens-Gruber R. Essential structural features of TNF-α lectin-like domain derived peptides for activation of amiloride-sensitive sodium current in A549 cells. J Med Chem 2010; 53:8021-9. [PMID: 20979368 DOI: 10.1021/jm100767p] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The amiloride-sensitive epithelial sodium channel (ENaC) plays a prominent role in sodium uptake from alveolar fluid and is the major component in alveolar fluid clearance in normal and diseased lungs. The lectin-like domain of TNF-α has been shown to activate amiloride-sensitive sodium uptake in type II alveolar epithelial cells. Therefore, several synthetic peptides that mimic the lectin-like domain of TNF-α (TIP) were synthesized and their ability to enhance sodium current through ENaC was studied in A549 cells with the patch clamp technique. Our data suggest that a free positively charged N-terminal amino group on residue 1 and/or a free negatively charged carboxyl group on residue 17 of the TIP peptide is essential for the ENaC-activating effect. Ventilation strategies apart, no standard treatment exists for pulmonary permeability edema. Therefore, novel therapies activating sodium uptake from the alveolar fluid via ENaC could improve clinical outcome.
Collapse
Affiliation(s)
- Parastoo Hazemi
- Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
| | | | | | | | | | | | | | | |
Collapse
|
30
|
|
31
|
The lectin-like domain of tumor necrosis factor improves lung function after rat lung transplantation--potential role for a reduction in reactive oxygen species generation. Crit Care Med 2010; 38:871-8. [PMID: 20081530 DOI: 10.1097/ccm.0b013e3181cdf725] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To test the hypothesis that the lectin-like domain of tumor necrosis factor, mimicked by the TIP peptide, can improve lung function after unilateral orthotopic lung isotransplantation. Because of a lack of a specific treatment for ischemia reperfusion-mediated lung injury, accompanied by a disrupted barrier integrity and a dysfunctional alveolar liquid clearance, alternative therapies restoring these parameters after lung transplantation are required. DESIGN Prospective, randomized laboratory investigation. SETTING University-affiliated laboratory. SUBJECTS Adult female rats. INTERVENTIONS Tuberoinfundibular peptide, mimicking the lectin-like domain of tumor necrosis factor, mutant TIP peptide, N,N'-diacetylchitobiose/TIP peptide, and amiloride/TIP peptide were instilled intratracheally in the left lung immediately before the isotransplantation was performed. An additional group received an intravenous TIP peptide treatment, 1.5 mins before transplantation. Studies using isolated rat type II alveolar epithelial cell monolayers and ovine pulmonary endothelial cells were also performed. MEASUREMENTS AND MAIN RESULTS Intratracheal pretreatment of the transplantable left lung with the TIP peptide, but not with an inactive mutant TIP peptide, resulted in significantly improved oxygenation 24 hrs after transplantation. This treatment led to a significantly reduced neutrophil content in the lavage fluid. Both the effects on oxygenation and neutrophil infiltration were inhibited by the epithelial sodium channel blocker amiloride. The TIP peptide blunted reactive oxygen species production in pulmonary artery endothelial cells under hypoxia and reoxygenation and reduced reactive oxygen species content in the transplanted rat lungs in vivo. Ussing chamber experiments using monolayers of primary type II rat pneumocytes indicated that the primary site of action of the peptide was on the apical side of these cells. CONCLUSIONS These data demonstrate that the TIP peptide significantly improves lung function after lung transplantation in the rat, in part, by reducing neutrophil content and reactive oxygen species generation. These studies suggest that the TIP peptide is a potential therapeutic agent against the ischemia reperfusion injury associated with lung transplantation.
Collapse
|
32
|
Xiong C, Yang G, Kumar S, Aggarwal S, Leustik M, Snead C, Hamacher J, Fischer B, Umapathy NS, Hossain H, Wendel A, Catravas JD, Verin AD, Fulton D, Black SM, Chakraborty T, Lucas R. The lectin-like domain of TNF protects from listeriolysin-induced hyperpermeability in human pulmonary microvascular endothelial cells - a crucial role for protein kinase C-alpha inhibition. Vascul Pharmacol 2010; 52:207-13. [PMID: 20074664 DOI: 10.1016/j.vph.2009.12.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 11/25/2009] [Accepted: 12/24/2009] [Indexed: 11/29/2022]
Abstract
Listeriosis can lead to potentially lethal pulmonary complications in newborns and immune compromised patients, characterized by extensive permeability edema. Listeriolysin (LLO), the main virulence factor of Listeria monocytogenes, induces a dose-dependent hyperpermeability in monolayers of human lung microvascular endothelial cells in vitro. The permeability increasing activity of LLO, which is accompanied by an increased reactive oxygen species (ROS) generation, RhoA activation and myosin light chain (MLC) phosphorylation, can be completely inhibited by the protein kinase C (PKC) alpha/beta inhibitor GO6976, indicating a crucial role for PKC in the induction of barrier dysfunction. The TNF-derived TIP peptide, which mimics the lectin-like domain of the cytokine, blunts LLO-induced hyperpermeability in vitro, upon inhibiting LLO-induced protein kinase C-alpha activation, ROS generation and MLC phosphorylation and upon restoring the RhoA/Rac 1 balance. These results indicate that the lectin-like domain of TNF has a potential therapeutic value in protecting from LLO-induced pulmonary endothelial hyperpermeability.
Collapse
|
33
|
Abstract
PURPOSE OF REVIEW The present review evaluates the evidence available in the literature tracking perioperative mortality and morbidity as well as the pathogenesis and management of acute lung injury (ALI) in patients undergoing thoracotomy. RECENT FINDINGS Over the last decade, despite increasing age and comorbid conditions, the operative mortality has remained unchanged for patients undergoing lung resection, whereas procedure-related complications have declined. Better clinical outcomes are achieved in high-volume hospitals and when procedures are performed by a thoracic surgeon. Postthoracotomy ALI has become the leading cause of operative death, its incidence has remained stable (2-5%) and earlier diagnosis can be made by assessing the extravascular lung water volume with the single-indicator dilution technique. The pathogenesis of ALI implicates a multiple-hit sequence of various triggering factors (e.g. oxidative stress and surgical-induced inflammation) in addition to injurious ventilatory settings and genetic predisposition. SUMMARY Knowledge of the perioperative risk factors of major complications and understanding of the mechanisms of postthoracotomy ALI enable anesthesiologists to implement 'protective' lung strategies including the use of low tidal volume (VT) with recruitment maneuvers, a goal-directed fluid approach and prophylactic treatment with inhaled beta2-adrenergic agonists.
Collapse
|
34
|
Regulators of endothelial and epithelial barrier integrity and function in acute lung injury. Biochem Pharmacol 2009; 77:1763-72. [PMID: 19428331 DOI: 10.1016/j.bcp.2009.01.014] [Citation(s) in RCA: 191] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 01/22/2009] [Accepted: 01/22/2009] [Indexed: 12/12/2022]
Abstract
Permeability edema is a life-threatening complication accompanying acute lung injury (ALI), severe pneumonia and the acute respiratory distress syndrome (ARDS), which can be associated with a reduced alveolar liquid clearance (ALC) capacity, a disruption of the alveolar epithelial barrier, and an increased capillary endothelial permeability. Bacterial and viral infections can directly promote pulmonary endothelial hyperpermeability and indirectly decrease the function and/or expression of ion transporters regulating ALC in type II alveolar epithelial cells, by means of inducing a strong inflammatory and oxidative stress response in the infected lungs. Apart from ventilation strategies, no standard treatment exists for permeability edema, making the search for novel regulators of endothelial and epithelial hyperpermeability and dysfunction important. Here, we present an overview of recently identified substances that inhibit and/or reverse endothelial barrier disruption and permeability or alveolar epithelial dysfunction: (1) zinc chelators, which were shown to attenuate the effects of oxidative stress on the pulmonary endothelium; (2) peroxisome proliferator activated receptor (PPAR) ligands, which have been shown to exert anti-inflammatory effects, by decreasing the expression of pro-inflammatory genes; (3) extracellular ATP, produced during inflammation, which induces a rapid and dose-dependent increase in transendothelial electrical resistance (TER) across pulmonary endothelial cells; (4) the lectin-like domain of TNF, which is spatially distinct from the receptor binding sites and which protects from hydrostatic and permeability edema and (5) Hsp90 inhibitors, which prevent and repair toxin-induced hyperpermeability. Unraveling the mechanism of action of these agents could contribute to the development of novel therapeutic strategies to combat permeability edema.
Collapse
|
35
|
|