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Vargas Buonfiglio LG, Borcherding JA, Frommelt M, Parker GJ, Duchman B, Vanegas Calderón OG, Fernandez-Ruiz R, Noriega JE, Stone EA, Gerke AK, Zabner J, Comellas AP. Airway surface liquid from smokers promotes bacterial growth and biofilm formation via iron-lactoferrin imbalance. Respir Res 2018. [PMID: 29524964 PMCID: PMC5845328 DOI: 10.1186/s12931-018-0743-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background Smoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance. Methods We collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers. We challenged these samples using a standard inoculum of Staphylococcus aureus and Pseudomonas aeruginosa and quantified bacterial growth and biofilm formation. We measured both iron and lactoferrin in the samples. We investigated the effect of supplementing non-smoker BAL with cigarette smoke extract (CSE) or ferric chloride and the effect of supplementing smoker BAL with lactoferrin on bacterial growth and biofilm formation. Results BAL from smokers had increased bacterial growth and biofilm formation compared to non-smokers after both S. aureus and P. aeruginosa challenge. In addition, we found that samples from smokers had a higher iron to lactoferrin ratio. Supplementing the BAL of non-smokers with cigarette smoke extract and ferric chloride increased bacterial growth. Conversely, supplementing the BAL of smokers with lactoferrin had a concentration-dependent decrease in bacterial growth and biofilm formation. Conclusion Cigarette smoking produces factors which increase bacterial growth and biofilm formation in the BAL. We propose that smoking disrupts the iron-to-lactoferrin in the airways. This finding offers a new avenue for potential therapeutic interventions to prevent respiratory infections in smokers. Electronic supplementary material The online version of this article (10.1186/s12931-018-0743-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luis G Vargas Buonfiglio
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Jennifer A Borcherding
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Mark Frommelt
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Gavin J Parker
- Department of Chemistry, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA, USA
| | - Bryce Duchman
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Oriana G Vanegas Calderón
- Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Ruth Fernandez-Ruiz
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Julio E Noriega
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Elizabeth A Stone
- Department of Chemistry, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA, USA
| | - Alicia K Gerke
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Joseph Zabner
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA
| | - Alejandro P Comellas
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 6312 Pappajohn Biomedical Discovery Building. Newton Road, Iowa City, IA, 52242, USA.
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Vargas Buonfiglio LG, Mudunkotuwa IA, Abou Alaiwa MH, Vanegas Calderón OG, Borcherding JA, Gerke AK, Zabner J, Grassian VH, Comellas AP. Effects of Coal Fly Ash Particulate Matter on the Antimicrobial Activity of Airway Surface Liquid. Environ Health Perspect 2017; 125:077003. [PMID: 28696208 PMCID: PMC5744695 DOI: 10.1289/ehp876] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 12/30/2016] [Accepted: 01/19/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Sustained exposure to ambient particulate matter (PM) is a global cause of mortality. Coal fly ash (CFA) is a byproduct of coal combustion and is a source of anthropogenic PM with worldwide health relevance. The airway epithelia are lined with fluid called airway surface liquid (ASL), which contains antimicrobial proteins and peptides (AMPs). Cationic AMPs bind negatively charged bacteria to exert their antimicrobial activity. PM arriving in the airways could potentially interact with AMPs in the ASL to affect their antimicrobial activity. OBJECTIVES We hypothesized that PM can interact with ASL AMPs to impair their antimicrobial activity. METHODS We exposed pig and human airway explants, pig and human ASL, and the human cationic AMPs β-defensin-3, LL-37, and lysozyme to CFA or control. Thereafter, we assessed the antimicrobial activity of exposed airway samples using both bioluminescence and standard colony-forming unit assays. We investigated PM-AMP electrostatic interaction by attenuated total reflection Fourier-transform infrared spectroscopy and measuring the zeta potential. We also studied the adsorption of AMPs on PM. RESULTS We found increased bacterial survival in CFA-exposed airway explants, ASL, and AMPs. In addition, we report that PM with a negative surface charge can adsorb cationic AMPs and form negative particle-protein complexes. CONCLUSION We propose that when CFA arrives at the airway, it rapidly adsorbs AMPs and creates negative complexes, thereby decreasing the functional amount of AMPs capable of killing pathogens. These results provide a novel translational insight into an early mechanism for how ambient PM increases the susceptibility of the airways to bacterial infection. https://doi.org/10.1289/EHP876.
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Affiliation(s)
| | | | | | - Oriana G Vanegas Calderón
- Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | | | - Alicia K Gerke
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine
| | - Joseph Zabner
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry
- Department of Nanoengineering, and
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Alejandro P Comellas
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine
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Buonfiglio LGV, Bagegni M, Borcherding JA, Sieren JC, Caraballo JC, Reger A, Zabner J, Li X, Comellas AP. Protein Kinase Cζ Inhibitor Promotes Resolution of Bleomycin-Induced Acute Lung Injury. Am J Respir Cell Mol Biol 2017; 55:869-877. [PMID: 27486964 DOI: 10.1165/rcmb.2015-0006oc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Protein kinase Cζ (PKCζ) is highly expressed in the lung, where it plays several regulating roles in the pathogenesis of acute lung injury (ALI). Proliferation and differentiation of integrin β4+ distal lung epithelial progenitor cells seem to play a key role in proper lung regeneration. We investigated the effects of a myristoylated PKCζ inhibitor (PKCζi) in a murine model of bleomycin-induced ALI. After intratracheal injury, we treated mice three times a week with PKCζi or its vehicle, DMSO. We found that mice injured with bleomycin and then treated with PKCζi for one week showed decreased activation of PKCζ, improved lung compliance, and decreased lung protein permeability compared to injured mice treated with DMSO. Mice treated continuously with PKCζi for 6 weeks showed reduced evidence of lung fibrosis by computed tomographic images, decreased lung collagen deposition, and decreased active transforming growth factor-β in the bronchoalveolar lavage fluid. In addition, we found an increased number of lung β4+ cells compared to DMSO at Week 6. Therefore, we grew isolated integrin β4+ lung progenitor cells in the presence of PKCζi or DMSO and found that β4+ cells treated with PKCζi proliferated more in vitro compared to DMSO. We conclude that the use of a PKCζi promotes resolution of lung fibrosis in a bleomycin ALI model and increases the number of β4+ progenitor cells with regenerative potential in the lung.
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Affiliation(s)
- Luis G Vargas Buonfiglio
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Mosaab Bagegni
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Jennifer A Borcherding
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | | | - Juan C Caraballo
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Andrew Reger
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Joseph Zabner
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Xiaopeng Li
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
| | - Alejandro P Comellas
- 1 Internal Medicine Department, Division of Pulmonary, Critical Care, and Occupational Medicine, and
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Monick MM, Baltrusaitis J, Powers LS, Borcherding JA, Caraballo JC, Mudunkotuwa I, Peate DW, Walters K, Thompson JM, Grassian VH, Gudmundsson G, Comellas AP. Effects of Eyjafjallajökull volcanic ash on innate immune system responses and bacterial growth in vitro. Environ Health Perspect 2013; 121:691-8. [PMID: 23478268 PMCID: PMC3672917 DOI: 10.1289/ehp.1206004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 03/07/2013] [Indexed: 05/24/2023]
Abstract
BACKGROUND On 20 March 2010, the Icelandic volcano Eyjafjallajökull erupted for the first time in 190 years. Despite many epidemiological reports showing effects of volcanic ash on the respiratory system, there are limited data evaluating cellular mechanisms involved in the response to ash. Epidemiological studies have observed an increase in respiratory infections in subjects and populations exposed to volcanic eruptions. METHODS We physicochemically characterized volcanic ash, finding various sizes of particles, as well as the presence of several transition metals, including iron. We examined the effect of Eyjafjallajökull ash on primary rat alveolar epithelial cells and human airway epithelial cells (20-100 µg/cm(2)), primary rat and human alveolar macrophages (5-20 µg/cm(2)), and Pseudomonas aeruginosa (PAO1) growth (3 µg/104 bacteria). RESULTS Volcanic ash had minimal effect on alveolar and airway epithelial cell integrity. In alveolar macrophages, volcanic ash disrupted pathogen-killing and inflammatory responses. In in vitro bacterial growth models, volcanic ash increased bacterial replication and decreased bacterial killing by antimicrobial peptides. CONCLUSIONS These results provide potential biological plausibility for epidemiological data that show an association between air pollution exposure and the development of respiratory infections. These data suggest that volcanic ash exposure, while not seriously compromising lung cell function, may be able to impair innate immunity responses in exposed individuals.
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Affiliation(s)
- Martha M Monick
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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Borcherding JA, Chen H, Caraballo JC, Baltrusaitis J, Pezzulo AA, Zabner J, Grassian VH, Comellas AP. Coal fly ash impairs airway antimicrobial peptides and increases bacterial growth. PLoS One 2013; 8:e57673. [PMID: 23469047 PMCID: PMC3585163 DOI: 10.1371/journal.pone.0057673] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/24/2013] [Indexed: 12/22/2022] Open
Abstract
Air pollution is a risk factor for respiratory infections, and one of its main components is particulate matter (PM), which is comprised of a number of particles that contain iron, such as coal fly ash (CFA). Since free iron concentrations are extremely low in airway surface liquid (ASL), we hypothesize that CFA impairs antimicrobial peptides (AMP) function and can be a source of iron to bacteria. We tested this hypothesis in vivo by instilling mice with Pseudomonas aeruginosa (PA01) and CFA and determine the percentage of bacterial clearance. In addition, we tested bacterial clearance in cell culture by exposing primary human airway epithelial cells to PA01 and CFA and determining the AMP activity and bacterial growth in vitro. We report that CFA is a bioavailable source of iron for bacteria. We show that CFA interferes with bacterial clearance in vivo and in primary human airway epithelial cultures. Also, we demonstrate that CFA inhibits AMP activity in vitro, which we propose as a mechanism of our cell culture and in vivo results. Furthermore, PA01 uses CFA as an iron source with a direct correlation between CFA iron dissolution and bacterial growth. CFA concentrations used are very relevant to human daily exposures, thus posing a potential public health risk for susceptible subjects. Although CFA provides a source of bioavailable iron for bacteria, not all CFA particles have the same biological effects, and their propensity for iron dissolution is an important factor. CFA impairs lung innate immune mechanisms of bacterial clearance, specifically AMP activity. We expect that identifying the PM mechanisms of respiratory infections will translate into public health policies aimed at controlling, not only concentration of PM exposure, but physicochemical characteristics that will potentially cause respiratory infections in susceptible individuals and populations.
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Affiliation(s)
- Jennifer A. Borcherding
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Haihan Chen
- Department of Chemical and Biochemical Engineering, Iowa City, Iowa, United States of America
| | - Juan C. Caraballo
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Jonas Baltrusaitis
- Central Microscopy Research Facility, University of Iowa, Iowa City, Iowa, United States of America
| | - Alejandro A. Pezzulo
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Joseph Zabner
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Vicki H. Grassian
- Department of Chemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Alejandro P. Comellas
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Caraballo JC, Yshii C, Butti ML, Westphal W, Borcherding JA, Allamargot C, Comellas AP. Hypoxia increases transepithelial electrical conductance and reduces occludin at the plasma membrane in alveolar epithelial cells via PKC-ζ and PP2A pathway. Am J Physiol Lung Cell Mol Physiol 2011; 300:L569-78. [PMID: 21257729 DOI: 10.1152/ajplung.00109.2010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
During pulmonary edema, the alveolar space is exposed to a hypoxic environment. The integrity of the alveolar epithelial barrier is required for the reabsorption of alveolar fluid. Tight junctions (TJ) maintain the integrity of this barrier. We set out to determine whether hypoxia creates a dysfunctional alveolar epithelial barrier, evidenced by an increase in transepithelial electrical conductance (G(t)), due to a decrease in the abundance of TJ proteins at the plasma membrane. Alveolar epithelial cells (AEC) exposed to mild hypoxia (Po(2) = 50 mmHg) for 30 and 60 min decreased occludin abundance at the plasma membrane and significantly increased G(t). Other cell adhesion molecules such as E-cadherin and claudins were not affected by hypoxia. AEC exposed to hypoxia increased superoxide, but not hydrogen peroxide (H(2)O(2)). Overexpression of superoxide dismutase 1 (SOD1) but not SOD2 prevented the hypoxia-induced G(t) increase and occludin reduction in AEC. Also, overexpression of catalase had a similar effect as SOD1, despite not detecting any increase in H(2)O(2) during hypoxia. Blocking PKC-ζ and protein phosphatase 2A (PP2A) prevented the hypoxia-induced occludin reduction at the plasma membrane and increase in G(t). In summary, we show that superoxide, PKC-ζ, and PP2A are involved in the hypoxia-induced increase in G(t) and occludin reduction at the plasma membrane in AEC.
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Affiliation(s)
- Juan Carlos Caraballo
- University of Iowa, Internal Medicine Department, Division of Pulmonary, Critical Care and Occupation Medicine, Iowa City, Iowa 52242, USA
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