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Wang J, Wang J, Wang X, Wang Z. Effect of Amphotericin B on the Thermodynamic Properties and Surface Morphology of the Pulmonary Surfactant Model Monolayer during Respiration. Molecules 2023; 28:4840. [PMID: 37375395 DOI: 10.3390/molecules28124840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
During the COVID-19 pandemic, the treatment of pulmonary fungal infection faced noteworthy challenges. Amphotericin B has shown promising therapeutic effects as an inhalation treatment for pulmonary fungal infections, especially those associated with the COVID-19 virus, due to its rare resistance. However, because the drug frequently produces renal toxicity, its effective dose is limited in clinical use. In this work, the DPPC/DPPG mixed monolayer was used as the pulmonary surfactant monolayer to study the interaction between amphotericin B and the pulmonary surfactant monolayer during inhalation therapy using the Langmuir technique and atomic force microscopy. The effects of different molar ratios of AmB on the thermodynamic properties and surface morphology of the pulmonary surfactant monolayer at different surface pressures was evaluated. The results showed that when the molar ratio of AmB to lipids in the pulmonary surfactant was less than 1:1, the main intermolecular force was attractive at a surface pressure greater than 10 mN/m. This drug had little effect on the phase transition point of the DPPC/DPPG monolayer, but decreased the height of the monolayer at 15 mN/m and 25 mN/m. When the molar ratio of AmB to lipids was greater than 1:1, the intermolecular force was mainly repulsive at a surface pressure greater than 15 mN/m, and AmB increased the height of the DPPC/DPPG monolayer at both 15 mN/m and 25 mN/m. These results are helpful in understanding the interaction between the pulmonary surfactant model monolayer and different doses of drugs at various surface tensions during respiration.
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Affiliation(s)
- Juan Wang
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Jia Wang
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Xinzhong Wang
- Xi'an Key Laboratory of Human-Machine Integration and Control Technology for Intelligent Rehabilitation, School of Computer Science, Xijing University, Xi'an 710123, China
| | - Zhen Wang
- Xi'an Key Laboratory of Human-Machine Integration and Control Technology for Intelligent Rehabilitation, School of Computer Science, Xijing University, Xi'an 710123, China
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2
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Höglund N, Nieminen P, Mustonen AM, Käkelä R, Tollis S, Koho N, Holopainen M, Ruhanen H, Mykkänen A. Fatty acid fingerprints in bronchoalveolar lavage fluid and its extracellular vesicles reflect equine asthma severity. Sci Rep 2023; 13:9821. [PMID: 37330591 PMCID: PMC10276833 DOI: 10.1038/s41598-023-36697-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 06/08/2023] [Indexed: 06/19/2023] Open
Abstract
Equine asthma (EA) is an inflammatory disease of the lower airways driven by mediators released from cells. Extracellular vesicles (EVs) are vehicles for lipid mediators, which possess either pro-inflammatory or dual anti-inflammatory and pro-resolving functions. In this study, we investigated how the respiratory fatty acid (FA) profile reflects airway inflammatory status. The FA composition of bronchoalveolar lavage fluid (BALF), BALF supernatant, and bronchoalveolar EVs of healthy horses (n = 15) and horses with mild/moderate EA (n = 10) or severe EA (SEA, n = 5) was determined with gas chromatography and mass spectrometry. The FA profiles distinguished samples with different diagnoses in all sample types, yet they were insufficient to predict the health status of uncategorized samples. Different individual FAs were responsible for the discrimination of the diagnoses in different sample types. Particularly, in the EVs of SEA horses the proportions of palmitic acid (16:0) decreased and those of eicosapentaenoic acid (20:5n-3) increased, and all sample types of asthmatic horses had elevated dihomo-γ-linolenic acid (20:3n-6) proportions. The results suggest simultaneous pro-inflammatory and resolving actions of FAs and a potential role for EVs as vehicles for lipid mediators in asthma pathogenesis. EV lipid manifestations of EA can offer translational targets to study asthma pathophysiology and treatment options.
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Affiliation(s)
- Nina Höglund
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, 00014, Helsinki, Finland.
| | - Petteri Nieminen
- School of Medicine, Faculty of Health Sciences, Institute of Biomedicine, University of Eastern Finland, 70211, Kuopio, Finland
| | - Anne-Mari Mustonen
- School of Medicine, Faculty of Health Sciences, Institute of Biomedicine, University of Eastern Finland, 70211, Kuopio, Finland
- Department of Environmental and Biological Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, 80101, Joensuu, Finland
| | - Reijo Käkelä
- Helsinki University Lipidomics Unit, HiLIPID, Helsinki Institute of Life Science, HiLIFE, and Biocenter Finland, 00014, Helsinki, Finland
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland
| | - Sylvain Tollis
- School of Medicine, Faculty of Health Sciences, Institute of Biomedicine, University of Eastern Finland, 70211, Kuopio, Finland
| | - Ninna Koho
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, 00014, Helsinki, Finland
| | - Minna Holopainen
- Helsinki University Lipidomics Unit, HiLIPID, Helsinki Institute of Life Science, HiLIFE, and Biocenter Finland, 00014, Helsinki, Finland
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland
| | - Hanna Ruhanen
- Helsinki University Lipidomics Unit, HiLIPID, Helsinki Institute of Life Science, HiLIFE, and Biocenter Finland, 00014, Helsinki, Finland
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland
| | - Anna Mykkänen
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, 00014, Helsinki, Finland
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Raith M, Swoboda I. Birch pollen-The unpleasant herald of spring. FRONTIERS IN ALLERGY 2023; 4:1181675. [PMID: 37255542 PMCID: PMC10225653 DOI: 10.3389/falgy.2023.1181675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/24/2023] [Indexed: 06/01/2023] Open
Abstract
Type I respiratory allergies to birch pollen and pollen from related trees of the order Fagales are increasing in industrialized countries, especially in the temperate zone of the Northern hemisphere, but the reasons for this increase are still debated and seem to be multifaceted. While the most important allergenic molecules of birch pollen have been identified and characterized, the contribution of other pollen components, such as lipids, non-allergenic immunomodulatory proteins, or the pollen microbiome, to the development of allergic reactions are sparsely known. Furthermore, what also needs to be considered is that pollen is exposed to external influences which can alter its allergenicity. These external influences include environmental factors such as gaseous pollutants like ozone or nitrogen oxides or particulate air pollutants, but also meteorological events like changes in temperature, humidity, or precipitation. In this review, we look at the birch pollen from different angles and summarize current knowledge on internal and external influences that have an impact on the allergenicity of birch pollen and its interactions with the epithelial barrier. We focus on epithelial cells since these cells are the first line of defense in respiratory disease and are increasingly considered to be a regulatory tissue for the protection against the development of respiratory allergies.
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Liu JY, Pradhan SH, Hussain S, Sayes CM. Platform for Exposing Aerosolized Substances to Lung Surfactant and Alveolar Cells at the Air-Liquid Interface. ACS CHEMICAL HEALTH & SAFETY 2022. [DOI: 10.1021/acs.chas.2c00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James Y. Liu
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
| | - Sahar H. Pradhan
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
| | - Saber Hussain
- 711th Human Performance Wing, Air Force Research Laboratory, Dayton, Ohio 45435, United States
| | - Christie M. Sayes
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
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Liu Q, Xue J, Zhang X, Chai J, Qin L, Guan J, Zhang X, Mao S. Biomimetic pulmonary surfactant modification on the in vivo fate of nanoparticles in the lung. Acta Biomater 2022; 147:391-402. [PMID: 35643196 DOI: 10.1016/j.actbio.2022.05.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 12/24/2022]
Abstract
Direct biomimetic modification of nanoparticles (NPs) with endogenous surfactants is helpful to improve the biocompatibility of NPs and avoid damage to the physiological function of the lung. Therefore, the objective of this study is to investigate the influence of biomimetic endogenous pulmonary surfactant phospholipid modification on the in vivo fate of NPs after lung delivery. Here, two neutral phospholipids (dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylamine (DPPE)) and two negatively charged phospholipids (dipalmitoylphosphatidylglycerol (DPPG), dipalmitoylphosphatidylserine (DPPS)) were selected to modify paclitaxel (PTX)-loaded PLGA NPs with different molar ratio. DPPC, DPPE, and DPPG improved mucoadhesion, in contrast, DPPS improved the mucus permeability of the NPs. Neutral DPPC and DPPE reduced, but negatively charged DPPS and DPPG increased the uptake by alveolar macrophages, all types of phospholipid increased the uptake by lung epithelial cells and increased PTX retention in the whole lung. Whereas, DPPC, DPPE, and DPPG promoted PTX retention in bronchoalveolar lavage fluid (BALF), while DPPS promoted PTX absorption in the lung tissue. Only DPPS-PLGA (1:1) NPs remarkably increased PTX systemic exposure. A good correlation between PTX percentage in the supernatant of BALF and PTX concentration in plasma was established, implying PTX entered the system circulation mainly in molecular form. Phospholipid modification had no effect on extrapulmonary organ distribution of PTX. Taken together, our study disclosed that different phospholipid modification can endow the NPs mucoadhesive or mucus penetration and cellular uptake properties, with tunable retention in BALF and absorption in the lung tissue, providing the scientific background for translational nanocarrier design for inhalation as required. STATEMENT OF SIGNIFICANCE: Inhaled nanomedicines will inevitably interact with pulmonary surfactant and form "surfactant corona". However, the contribution of individual pulmonary surfactant phospholipid on the in vivo fate of nanomedicines is still unclear. In this regard, the most abundant pulmonary surfactant phospholipid dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylamine, and dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylserine were selected to modify the paclitaxel loaded PLGA nanoparticles and the effect of these pulmonary surfactant phospholipids on their in vivo fate was investigated. It was demonstrated that different phospholipid modification can endow the nanoparticles mucoadhesive or mucus penetration properties, with tunable retention in bronchoalveolar lavage fluid, alveolar macrophages uptake and absorption in the lung tissue. The present study provided a comprehensive understanding for the role of pulmonary surfactant phospholipid on inhaled nanomedicines.
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Affiliation(s)
- Qiaoyu Liu
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Jingwen Xue
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Xinrui Zhang
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Juanjuan Chai
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Lu Qin
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Jian Guan
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Xin Zhang
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Shirui Mao
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China.
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Liu Q, Guan J, Song R, Zhang X, Mao S. Physicochemical properties of nanoparticles affecting their fate and the physiological function of pulmonary surfactants. Acta Biomater 2022; 140:76-87. [PMID: 34843949 DOI: 10.1016/j.actbio.2021.11.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 11/10/2021] [Accepted: 11/23/2021] [Indexed: 12/22/2022]
Abstract
Pulmonary drug delivery has drawn great attention due to its targeted local lung action, reduced side effects, and ease of administration. However, inhaled nanoparticles (NPs) could adsorb different pulmonary surfactants depending on their physicochemical properties, which may impair the physiological function of the pulmonary surfactants or alter the fate of the NPs. Thus, the objective of this review is to summarize how the physicochemical properties of NPs affecting the physiological function of pulmonary surfactants and their fate. First of all, the composition and characteristics of pulmonary surfactants, methods for studying pulmonary surfactant interaction with NPs are introduced. Thereafter, the influence of physicochemical properties of NPs on hydrophobic protein adsorption and strategies to decrease the interaction of NPs with pulmonary surfactants are discussed. Finally, the influence of physicochemical properties of NPs on lipids and hydrophilic protein adsorption and consequently their fate is described. In conclusion, a better understanding of the interaction of NPs with pulmonary surfactants will promote the faster development of safe and effective nanomedicine for pulmonary drug delivery. STATEMENT OF SIGNIFICANCE: Drug delivery carriers often face complex body fluid components after entering the human body. Pulmonary surfactants diffuse at the lung gas-liquid interface, and particles inevitably interact with pulmonary surfactants after pulmonary nanomedicine delivery. This review presents an overview of how the physicochemical properties of nanoparticles affecting their fate and physiological function of pulmonary surfactants. We believe that the information included in this review can provide important guiding for the development of safe and effective pulmonary delivery nanocarriers.
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Milad N, Morissette MC. Revisiting the role of pulmonary surfactant in chronic inflammatory lung diseases and environmental exposure. Eur Respir Rev 2021; 30:30/162/210077. [PMID: 34911693 DOI: 10.1183/16000617.0077-2021] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/05/2021] [Indexed: 12/12/2022] Open
Abstract
Pulmonary surfactant is a crucial and dynamic lung structure whose primary functions are to reduce alveolar surface tension and facilitate breathing. Though disruptions in surfactant homeostasis are typically thought of in the context of respiratory distress and premature infants, many lung diseases have been noted to have significant surfactant abnormalities. Nevertheless, preclinical and clinical studies of pulmonary disease too often overlook the potential contribution of surfactant alterations - whether in quantity, quality or composition - to disease pathogenesis and symptoms. In inflammatory lung diseases, whether these changes are cause or consequence remains a subject of debate. This review will outline 1) the importance of pulmonary surfactant in the maintenance of respiratory health, 2) the diseases associated with primary surfactant dysregulation, 3) the surfactant abnormalities observed in inflammatory pulmonary diseases and, finally, 4) the available research on the interplay between surfactant homeostasis and smoking-associated lung disease. From these published studies, we posit that changes in surfactant integrity and composition contribute more considerably to chronic inflammatory pulmonary diseases and that more work is required to determine the mechanisms underlying these alterations and their potential treatability.
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Affiliation(s)
- Nadia Milad
- Faculty of Medicine, Université Laval, Quebec City, QC, Canada.,Quebec Heart and Lung Institute - Université Laval, Quebec City, QC, Canada
| | - Mathieu C Morissette
- Quebec Heart and Lung Institute - Université Laval, Quebec City, QC, Canada .,Dept of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
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8
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Wu M, Wang F, Chen J, Zhang H, Zeng H, Liu J. Interactions of model airborne particulate matter with dipalmitoyl phosphatidylcholine and a clinical surfactant Calsurf. J Colloid Interface Sci 2021; 607:1993-2009. [PMID: 34798708 DOI: 10.1016/j.jcis.2021.09.193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 12/31/2022]
Abstract
HYPOTHESIS Lung surfactant protects lung tissue and reduces the surface tension in the alveoli during respiration. Particulate matter with an aerodynamic diameter of less than 2.5 μm (PM2.5), which invades primely through inhalation, can deposit on and interact with the surfactant layer, leading to changes in the biophysical and morphological properties of the lung surfactant. EXPERIMENTS Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and clinical surfactant Calsurf were investigated with a PM2.5 model injected into the water subphase, which were characterized by surface pressure-area isotherms, Brewster angle microscopy, atomic force microscopy, fluorescent microscopy, and x-ray photoelectron spectroscopy. The binding between DPPC/Calsurf and PM2.5 was studied using isothermal titration calorimetry. FINDINGS PM2.5 induced the expansion of the monolayers at low surface pressure (п) and film condensation at high п. Aggregation of PM2.5 mainly occurred at the interface of liquid expanded/liquid condensed (LE/LC) phases. PM2.5 led to slimmer and ramified LC domains on DPPC and the reduction of nano-sized condensed domains on Calsurf. Both DPPC and Calsurf showed fast binding with PM2.5 through complex binding modes attributed to the heterogeneity and amphiphilic property of PM2.5. This study improves the fundamental understanding of PM2.5-lung surfactant interaction and shows useful implications of the toxicity of PM2.5 through respiration process.
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Affiliation(s)
- Min Wu
- The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510700, China; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Feifei Wang
- The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510700, China; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Jingsi Chen
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Jifang Liu
- The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510700, China.
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Roach KA, Stefaniak AB, Roberts JR. Metal nanomaterials: Immune effects and implications of physicochemical properties on sensitization, elicitation, and exacerbation of allergic disease. J Immunotoxicol 2019; 16:87-124. [PMID: 31195861 PMCID: PMC6649684 DOI: 10.1080/1547691x.2019.1605553] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 03/15/2019] [Accepted: 04/05/2019] [Indexed: 12/25/2022] Open
Abstract
The recent surge in incorporation of metallic and metal oxide nanomaterials into consumer products and their corresponding use in occupational settings have raised concerns over the potential for metals to induce size-specific adverse toxicological effects. Although nano-metals have been shown to induce greater lung injury and inflammation than their larger metal counterparts, their size-related effects on the immune system and allergic disease remain largely unknown. This knowledge gap is particularly concerning since metals are historically recognized as common inducers of allergic contact dermatitis, occupational asthma, and allergic adjuvancy. The investigation into the potential for adverse immune effects following exposure to metal nanomaterials is becoming an area of scientific interest since these characteristically lightweight materials are easily aerosolized and inhaled, and their small size may allow for penetration of the skin, which may promote unique size-specific immune effects with implications for allergic disease. Additionally, alterations in physicochemical properties of metals in the nano-scale greatly influence their interactions with components of biological systems, potentially leading to implications for inducing or exacerbating allergic disease. Although some research has been directed toward addressing these concerns, many aspects of metal nanomaterial-induced immune effects remain unclear. Overall, more scientific knowledge exists in regards to the potential for metal nanomaterials to exacerbate allergic disease than to their potential to induce allergic disease. Furthermore, effects of metal nanomaterial exposure on respiratory allergy have been more thoroughly-characterized than their potential influence on dermal allergy. Current knowledge regarding metal nanomaterials and their potential to induce/exacerbate dermal and respiratory allergy are summarized in this review. In addition, an examination of several remaining knowledge gaps and considerations for future studies is provided.
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Affiliation(s)
- Katherine A Roach
- a Allergy and Clinical Immunology Branch (ACIB) , National Institute of Occupational Safety and Health (NIOSH) , Morgantown , WV , USA
- b School of Pharmacy , West Virginia University , Morgantown , WV , USA
| | - Aleksandr B Stefaniak
- c Respiratory Health Division (RHD) , National Institute of Occupational Safety and Health (NIOSH) , Morgantown , WV , USA
| | - Jenny R Roberts
- a Allergy and Clinical Immunology Branch (ACIB) , National Institute of Occupational Safety and Health (NIOSH) , Morgantown , WV , USA
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Beck-Broichsitter M, Bohr A. Bioinspired polymer nanoparticles omit biophysical interactions with natural lung surfactant. Nanotoxicology 2019; 13:964-976. [PMID: 31109226 DOI: 10.1080/17435390.2019.1621400] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Herein, we report the attenuated impact of bioinspired nanoparticles on the essential function of lung surfactant. Colloidal particles made from poly(lactide) caused a significant loss of surfactant protein B (and C) from a natural lung surfactant accompanied by a decline in surface activity under static conditions and surface area cycling. No such perturbation of lung surfactant composition and function was observed for polymer nanoparticles coated with bioinspired poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC). More specifically, increasing the PMPC-coating layer thickness (≥3 nm) and density (dense conformation, distance of individual polymer chains of ≤3 nm) on the polymer nanoparticle surface diminished bioadverse events. PMPC-coated poly(lactide) nanoparticles provoked a less severe perturbation of the utilized lung surfactant when compared to colloidal counterparts coated with poly(ethylene glycol). Overall, a steric shielding of colloidal drug delivery vehicles with bioinspired PMPC can be considered as a valuable approach for the rationale development of biocompatible nanomedicines intended for lung delivery.
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Affiliation(s)
- Moritz Beck-Broichsitter
- Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität , Giessen , Germany
| | - Adam Bohr
- Department of Pharmacy, University of Copenhagen , Copenhagen , Denmark
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11
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Comparison of two methods of determining lung de-recruitment, using the forced oscillation technique. Eur J Appl Physiol 2018; 118:2213-2224. [PMID: 30062516 DOI: 10.1007/s00421-018-3949-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/21/2018] [Indexed: 10/28/2022]
Abstract
Airway closure has proved to be important in a number of respiratory diseases and may be the primary functional defect in asthma. A surrogate measure of closing volume can be identified using the forced oscillation technique (FOT), by performing a deflation maneuver and examining the resultant reactance (Xrs) lung volume relationship. This study aims to determine if a slow vital capacity maneuver can be used instead of this deflation maneuver and compare it to existing more complex techniques. Three subject groups were included in the study; healthy (n = 29), asthmatic (n = 18), and COPD (n = 10) for a total of 57 subjects. Reactance lung volume curves were generated via FOT recordings during two different breathing manoeuvres (both pre and post bronchodilator). The correlation and agreement between surrogate closing volume (Volcrit) and reactance (Xrscrit) at this volume was analysed. The changes in Volcrit and Xrscrit pre and post bronchodilator were also analysed. Across all three subject groups, the two different measures of Volcrit were shown to be statistically equivalent (p > 0.05) and demonstrated a strong fit to the data (R2 = 0.49, 0.78, 0.59, for asthmatic, COPD and healthy subject groups, respectively). A bias was evident between the two measurements of Xrscrit with statistically different means (p < 0.05). However, the two measurements of Xrscrit displayed the same trends. In conclusion, we have developed an alternative technique for measuring airway closure from FOT recordings. The technique delivers equivalent and possibly more sensitive results to previous methods while being simple and easily performed by the patient.
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12
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Lugogo N, Francisco D, Addison KJ, Manne A, Pederson W, Ingram JL, Green CL, Suratt BT, Lee JJ, Sunday ME, Kraft M, Ledford JG. Obese asthmatic patients have decreased surfactant protein A levels: Mechanisms and implications. J Allergy Clin Immunol 2017. [PMID: 28624607 DOI: 10.1016/j.jaci.2017.05.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Eosinophils are prominent in some patients with asthma and are increased in the submucosa in a subgroup of obese patients with asthma (OAs). Surfactant protein A (SP-A) modulates host responses to infectious and environmental insults. OBJECTIVE We sought to determine whether SP-A levels are altered in OAs compared with a control group and to determine the implications of these alterations in SP-A levels in asthmatic patients. METHODS Bronchoalveolar lavage fluid from 23 lean, 12 overweight, and 20 obese subjects were examined for SP-A. Mouse tracheal epithelial cells grown at an air-liquid interface were used for mechanistic studies. SP-A-/- mice were challenged in allergen models, and exogenous SP-A therapy was given after the last challenge. Eosinophils were visualized and quantitated in lung parenchyma by means of immunostaining. RESULTS Significantly less SP-A (P = .002) was detected in samples from OAs compared with those from control subjects. A univariable regression model found SP-A levels were significantly negatively correlated with body mass index (r = -0.33, P = .014), whereas multivariable modeling demonstrated that the correlation depended both on asthma status (P = .017) and the interaction of asthma and body mass index (P = .008). Addition of exogenous TNF-α to mouse tracheal epithelial cells was sufficient to attenuate SP-A and eotaxin secretion. Allergen-challenged SP-A-/- mice that received SP-A therapy had significantly less tissue eosinophilia compared with mice receiving vehicle. CONCLUSIONS SP-A functions as an important mediator in resolving tissue and lavage fluid eosinophilia in allergic mouse models. Decreased levels of SP-A in OAs, which could be due to increased local TNF-α levels, might lead to impaired eosinophil resolution and could contribute to the eosinophilic asthma phenotype.
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Affiliation(s)
- Njira Lugogo
- Department of Medicine, Duke University Medical Center, Durham, NC
| | - Dave Francisco
- Department of Medicine, University of Arizona, Tucson, Ariz
| | | | - Akarsh Manne
- Department of Medicine, University of Arizona, Tucson, Ariz
| | | | | | - Cynthia L Green
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC
| | | | - James J Lee
- Department of Biochemistry and Molecular Biology, Mayo Clinic Arizona, Scottsdale, Ariz
| | - Mary E Sunday
- Department of Pathology, Duke University Medical Center, Durham, NC
| | - Monica Kraft
- Department of Medicine, University of Arizona, Tucson, Ariz
| | - Julie G Ledford
- Department of Medicine, University of Arizona, Tucson, Ariz; Department of Immunobiology, University of Arizona, Tucson, Ariz.
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13
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Beck-Broichsitter M. Biophysical Activity of Impaired Lung Surfactant upon Exposure to Polymer Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10422-10429. [PMID: 27641633 DOI: 10.1021/acs.langmuir.6b02893] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Colloidal drug carriers could improve the therapy of numerous airway diseases. However, it remains unclear to what extent nanoscale particulate matter affects the biophysical function of the essential surface-active lining layer of the lungs, especially under predisposed conditions of airway diseases. Accordingly, the current study investigated the impact of defined polymer nanoparticles on impaired lung surfactants. Admixtures of plasma proteins (albumin and fibrinogen) to Curosurf led to a controllable decrease in surface activity (i.e., adsorption and minimal surface tension of >25 and >5 mN/m, respectively), which served as models for dysfunctional lung surfactants. Next, Curosurf preincubated with plasma proteins was challenged with negatively- and positively charged poly(lactide) nanoparticles. Negatively charged nanoparticles significantly perturbed the biophysical function of impaired Curosurf in a dose-dependent manner, most-likely due to a binding of essential surfactant components. By contrast, addition of positively charged nanoparticles led to no further loss of surface activity, but a remarkable depletion of plasma protein content. Once adsorbed to the surface of polymer nanoparticles, plasma proteins were hindered to displace relevant surfactant components from the air/liquid interface. Overall, the current study indicated that, depending on their physicochemical properties, colloidal drug carriers could compromise the biophysical function of impaired lung surfactants. Notably, a positive surface charge represents a parameter for the rationale design of polymer nanomedicines causing negligible adverse events on an impaired surface-active lining layer in the lungs.
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Affiliation(s)
- Moritz Beck-Broichsitter
- Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität , 35392 Giessen, Germany
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Kumar RK, Herbert C, Foster PS. Mouse models of acute exacerbations of allergic asthma. Respirology 2016; 21:842-9. [PMID: 26922049 DOI: 10.1111/resp.12760] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 11/29/2015] [Accepted: 01/23/2016] [Indexed: 12/24/2022]
Abstract
Most of the healthcare costs associated with asthma relate to emergency department visits and hospitalizations because of acute exacerbations of underlying chronic disease. Development of appropriate animal models of acute exacerbations of asthma is a necessary prerequisite for understanding pathophysiological mechanisms and assessing potential novel therapeutic approaches. Most such models have been developed using mice. Relatively few mouse models attempt to simulate the acute-on-chronic disease that characterizes human asthma exacerbations. Instead, many reported models involve relatively short-term challenge with an antigen to which animals are sensitized, followed closely by an unrelated triggering agent, so are better described as models of potentiation of acute allergic inflammation. Triggers for experimental models of asthma exacerbations include (i) challenge with high levels of the sensitizing allergen (ii) infection by viruses or fungi, or challenge with components of these microorganisms (iii) exposure to environmental pollutants. In this review, we examine the strengths and weaknesses of published mouse models, their application for investigation of novel treatments and potential future developments.
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Affiliation(s)
- Rakesh K Kumar
- Department of Pathology, School of Medical Sciences, UNSW Australia, Sydney
| | - Cristan Herbert
- Department of Pathology, School of Medical Sciences, UNSW Australia, Sydney
| | - Paul S Foster
- Centre for Asthma and Respiratory Disease, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
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15
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Busley D, Ochs M, Hoeltig D, Ganter M, Acevedo C, Schmiedl A, Hennig-Pauka I. Characterization of surfactant alterations in pigs infected withActinobacillus pleuropneumoniae. Exp Lung Res 2016; 42:1-13. [DOI: 10.3109/01902148.2015.1123327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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16
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Carraro S, Giordano G, Pirillo P, Maretti M, Reniero F, Cogo PE, Perilongo G, Stocchero M, Baraldi E. Airway metabolic anomalies in adolescents with bronchopulmonary dysplasia: new insights from the metabolomic approach. J Pediatr 2015; 166:234-9.e1. [PMID: 25294602 DOI: 10.1016/j.jpeds.2014.08.049] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 07/23/2014] [Accepted: 08/26/2014] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To assess a group of adolescents with bronchopulmonary dysplasia (BPD) from a biochemical-metabolic standpoint, applying the metabolomic approach to studying their exhaled breath condensate (EBC). STUDY DESIGN Twenty adolescents with BPD (mean age 14.8 years) and 15 healthy controls (mean age 15.2 years) were recruited for EBC collection, exhaled nitric oxide measurement, and spirometry. The EBC samples were analyzed using a metabolomic approach based on mass spectrometry. The obtained spectra were analyzed using multivariate statistical analysis tools. RESULTS A reliable Orthogonal Projections to Latent Structures-Discriminant Analysis model showed a clear discrimination between cases of BPD and healthy controls (R(2) = 0.95 and Q(2) = 0.92). The search for putative biomarkers identified an altered complex lipid profile in the adolescents with BPD. CONCLUSIONS The metabolomic analysis of EBC distinguishes cases of BPD from healthy individuals, suggesting that the lung of survivors of BPD is characterized by long-term metabolic abnormalities. The search for putative biomarkers indicated a possible role of an altered surfactant composition, which may persist far beyond infancy.
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Affiliation(s)
- Silvia Carraro
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | - Giuseppe Giordano
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | - Paola Pirillo
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | - Michela Maretti
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | - Fabiano Reniero
- European Commission, Joint Research Center, Institute for Health and Consumer Protection (IHCP), System Toxicology Unit (ST), Ispra (VA), Italy
| | - Paola E Cogo
- Anesthesia and Cardiac Intensive Care, Bambino Gesù Pediatric Hospital, Rome, Italy
| | - Giorgio Perilongo
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | | | - Eugenio Baraldi
- Women's and Children's Health Department, University of Padova, Padova, Italy.
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Ledford JG, Addison KJ, Foster MW, Que LG. Eosinophil-associated lung diseases. A cry for surfactant proteins A and D help? Am J Respir Cell Mol Biol 2015; 51:604-14. [PMID: 24960334 DOI: 10.1165/rcmb.2014-0095tr] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Surfactant proteins (SP)-A and SP-D (SP-A/-D) play important roles in numerous eosinophil-dominated diseases, including asthma, allergic bronchopulmonary aspergillosis, and allergic rhinitis. In these settings, SP-A/-D have been shown to modulate eosinophil chemotaxis, inhibit eosinophil mediator release, and mediate macrophage clearance of apoptotic eosinophils. Dysregulation of SP-A/-D function in eosinophil-dominated diseases is also not uncommon. Alterations in serum SP-A/-D levels are associated with disease severity in allergic rhinitis and chronic obstructive pulmonary disease. Furthermore, oligimerization of SP-A/-D, necessary for their proper function, can be perturbed by reactive nitrogen species, which are increased in eosinophilic disease. In this review, we highlight the associations of eosinophilic lung diseases with SP-A and SP-D levels and functions.
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Affiliation(s)
- Julie G Ledford
- 1 Department of Medicine, Division of Pulmonary, Allergy and Critical Care, and
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Dijkstra D, Hennig C, Hansen G, Biller H, Krug N, Hohlfeld JM. Identification and quantification of basophils in the airways of asthmatics following segmental allergen challenge. Cytometry A 2014; 85:580-7. [PMID: 24733663 DOI: 10.1002/cyto.a.22472] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/05/2014] [Accepted: 03/28/2014] [Indexed: 11/10/2022]
Abstract
During asthma attacks, allergens activate sensitized basophils in the lung, thereby aggravating symptoms. Due to the paucity of basophils in bronchial lavage fluid and the lack of specific basophil detection and quantification methods, basophil-directed research in these samples was hampered in the past. This study aimed to establish and validate a flow cytometry-based basophil detection and quantification method for human basophils from bronchoalveolar lavage (BAL) and blood as a prerequisite for a better understanding of their pathogenic contribution and subtyping of asthma phenotypes. BAL and blood leukocytes from seasonal asthmatics were analyzed by flow cytometry. Chipcytometry, a highly sensitive single-cell analysis method, was used to validate the staining panel for basophils. Cell differentials of May-Grünwald-Giemsa-stained cytospins were used to compare basophil percentages. BAL basophils are identifiable as CD123(+) HLA-DR(-) CD3(-) CD14(-) CD19(-) CD20(-) CD56(-) cells in flow cytometrical analysis. Their identity was validated by Chipcytometry. CD203c was highly expressed by BAL basophils, whereas it was expressed at variable levels on blood basophils. The two quantification methods correlated, although more basophils were detected by flow cytometry. Furthermore, the increase in basophil percentages in the lung correlated with the decrease in the basophil percentages in the blood after allergen challenge. We here validated a reliable basophil quantification method, which is independent of the cell's activation and degranulation state. The results obtained with this method indicate that basophils are directly recruited from the blood circulation to the airway lumen.
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Affiliation(s)
- Dorothea Dijkstra
- Department of Clinical Airway Research, Fraunhofer Institute for Toxicology and Experimental Medicine, D-30625, Hannover, Germany; Department of Pediatric Pneumology, Allergology, and Neonatology, Hannover Medical School, D-30625, Hannover, Germany
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Siddiqui S, Tsuchiya K, Risse PA, Bullimore SR, Benedetti A, Martin JG. Site of allergic airway narrowing and the influence of exogenous surfactant in the Brown Norway rat. PLoS One 2012; 7:e29381. [PMID: 22276110 PMCID: PMC3261862 DOI: 10.1371/journal.pone.0029381] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 11/28/2011] [Indexed: 11/18/2022] Open
Abstract
Background The parameters RN (Newtonian resistance), G (tissue damping), and H (tissue elastance) of the constant phase model of respiratory mechanics provide information concerning the site of altered mechanical properties of the lung. The aims of this study were to compare the site of allergic airway narrowing implied from respiratory mechanics to a direct assessment by morphometry and to evaluate the effects of exogenous surfactant administration on the site and magnitude of airway narrowing. Methods We induced airway narrowing by ovalbumin sensitization and challenge and we tested the effects of a natural surfactant lacking surfactant proteins A and D (Infasurf®) on airway responses. Sensitized, mechanically ventilated Brown Norway rats underwent an aerosol challenge with 5% ovalbumin or vehicle. Other animals received nebulized surfactant prior to challenge. Three or 20 minutes after ovalbumin challenge, airway luminal areas were assessed on snap-frozen lungs by morphometry. Results At 3 minutes, RN and G detected large airway narrowing whereas at 20 minutes G and H detected small airway narrowing. Surfactant inhibited RN at the peak of the early allergic response and ovalbumin-induced increase in bronchoalveolar lavage fluid cysteinyl leukotrienes and amphiregulin but not IgE-induced mast cell activation in vitro. Conclusion Allergen challenge triggers the rapid onset of large airway narrowing, detected by RN and G, and subsequent peripheral airway narrowing detected by G and H. Surfactant inhibits airway narrowing and reduces mast cell-derived mediators.
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Affiliation(s)
- Sana Siddiqui
- Meakins-Christie Laboratories, Department of Medicine, McGill University, and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Kimitake Tsuchiya
- Meakins-Christie Laboratories, Department of Medicine, McGill University, and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Paul-André Risse
- Meakins-Christie Laboratories, Department of Medicine, McGill University, and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Sharon R. Bullimore
- Meakins-Christie Laboratories, Department of Medicine, McGill University, and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Andrea Benedetti
- Meakins-Christie Laboratories, Department of Medicine, McGill University, and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - James G. Martin
- Meakins-Christie Laboratories, Department of Medicine, McGill University, and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
- * E-mail:
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Bühling F, Kouadio M, Chwieralski CE, Kern U, Hohlfeld JM, Klemm N, Friedrichs N, Roth W, Deussing JM, Peters C, Reinheckel T. Gene targeting of the cysteine peptidase cathepsin H impairs lung surfactant in mice. PLoS One 2011; 6:e26247. [PMID: 22022579 PMCID: PMC3192174 DOI: 10.1371/journal.pone.0026247] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 09/23/2011] [Indexed: 11/18/2022] Open
Abstract
Background The 11 human cysteine cathepsins are proteases mainly located in the endolysosomal compartment of all cells and within the exocytosis pathways of some secretory cell types. Cathepsin H (Ctsh) has amino- and endopeptidase activities. In vitro studies have demonstrated Ctsh involvement in the processing and secretion of the pulmonary surfactant protein B (SP-B). Furthermore, Ctsh is highly expressed in the secretory organelles of alveolar type II pneumocytes where the surfactant proteins are processed. Methodology/Principal Findings Hence, we generated Ctsh null mice by gene targeting in embryonic stem cells to investigate the role of this protease in surfactant processing in vivo. The targeting construct contains a ß-galactosidase (lacZ) reporter enabling the visualisation of Ctsh expression sites. Ctsh-deficiency was verified by northern blot, western blot, and measurement of the Ctsh aminopeptidase activity. Ctsh−/− mice show no gross phenotype and their development is normal without growth retardation. Broncho-alveolar lavage (BAL) from Ctsh−/− mice contained lower levels of SP-B indicating reduced SP-B secretion. The BAL phospholipid concentration was not different in Ctsh+/+ and Ctsh−/− mice, but measurement of surface tension by pulsating bubble surfactometry revealed an impairment of the tension reducing function of lung surfactant of Ctsh−/− mice. Conclusions/Significance We conclude that cathepsin H is involved in the SP-B production and reduced SP-B levels impair the physical properties of the lung surfactant. However, Ctsh defiency does not reproduce the severe phenotype of SP-B deficient mice. Hence, other proteases of the secretory pathway of type II pneumocytes, i.e. cathepsins C or E, are still able to produce surfactant of sufficient quality in absence of Ctsh.
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Affiliation(s)
- Frank Bühling
- Institute of Laboratory Medicine, Carl-Thiem-Klinikum, Cottbus, Germany
| | - Martin Kouadio
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
| | - Caroline E. Chwieralski
- Insitute of Molecular and Clinical Immunology, Otto-von-Guericke University, Magdeburg, Germany
| | - Ursula Kern
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
- Faculty of Biology, Albert-Ludwigs-University, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University, Freiburg, Germany
| | - Jens M. Hohlfeld
- Division of Immunology, Allergology and Airway Research, Fraunhofer Institute of Toxicology and Experimental Medicine, Hannover, Germany
| | - Nicole Klemm
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
| | - Nicole Friedrichs
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
| | - Wera Roth
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
| | - Jan M. Deussing
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
| | - Christoph Peters
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
- BIOSS Centre of Biological Signalling Studies, Albert-Ludwigs-University, Freiburg, Germany
| | - Thomas Reinheckel
- Institut of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany
- BIOSS Centre of Biological Signalling Studies, Albert-Ludwigs-University, Freiburg, Germany
- * E-mail:
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Beck-Broichsitter M, Ruppert C, Schmehl T, Guenther A, Betz T, Bakowsky U, Seeger W, Kissel T, Gessler T. Biophysical investigation of pulmonary surfactant surface properties upon contact with polymeric nanoparticles in vitro. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2011; 7:341-50. [DOI: 10.1016/j.nano.2010.10.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 10/12/2010] [Accepted: 10/17/2010] [Indexed: 02/05/2023]
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Christmann U, Hite RD, Tan RHH, Thatcher CD, Witonsky SG, Werre SR, Buechner-Maxwell VA. Surfactant alterations in horses with recurrent airway obstruction at various clinical stages. Am J Vet Res 2010; 71:468-75. [DOI: 10.2460/ajvr.71.4.468] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Schleh C, Mühlfeld C, Pulskamp K, Schmiedl A, Nassimi M, Lauenstein HD, Braun A, Krug N, Erpenbeck VJ, Hohlfeld JM. The effect of titanium dioxide nanoparticles on pulmonary surfactant function and ultrastructure. Respir Res 2009; 10:90. [PMID: 19793393 PMCID: PMC2765946 DOI: 10.1186/1465-9921-10-90] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Accepted: 09/30/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pulmonary surfactant reduces surface tension and is present at the air-liquid interface in the alveoli where inhaled nanoparticles preferentially deposit. We investigated the effect of titanium dioxide (TiO(2)) nanosized particles (NSP) and microsized particles (MSP) on biophysical surfactant function after direct particle contact and after surface area cycling in vitro. In addition, TiO(2) effects on surfactant ultrastructure were visualized. METHODS A natural porcine surfactant preparation was incubated with increasing concentrations (50-500 microg/ml) of TiO(2) NSP or MSP, respectively. Biophysical surfactant function was measured in a pulsating bubble surfactometer before and after surface area cycling. Furthermore, surfactant ultrastructure was evaluated with a transmission electron microscope. RESULTS TiO(2) NSP, but not MSP, induced a surfactant dysfunction. For TiO(2) NSP, adsorption surface tension (gammaads) increased in a dose-dependent manner from 28.2 + or - 2.3 mN/m to 33.2 + or - 2.3 mN/m (p < 0.01), and surface tension at minimum bubble size (gammamin) slightly increased from 4.8 + or - 0.5 mN/m up to 8.4 + or - 1.3 mN/m (p < 0.01) at high TiO(2) NSP concentrations. Presence of NSP during surface area cycling caused large and significant increases in both gammaads (63.6 + or - 0.4 mN/m) and gammamin (21.1 + or - 0.4 mN/m). Interestingly, TiO(2) NSP induced aberrations in the surfactant ultrastructure. Lamellar body like structures were deformed and decreased in size. In addition, unilamellar vesicles were formed. Particle aggregates were found between single lamellae. CONCLUSION TiO(2) nanosized particles can alter the structure and function of pulmonary surfactant. Particle size and surface area respectively play a critical role for the biophysical surfactant response in the lung.
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Affiliation(s)
- Carsten Schleh
- Fraunhofer Institute of Toxicology and Experimental Medicine, Division of Immunology, Allergology and Airway Research, Nikolai-Fuchs-Str, 1, 30625 Hannover, Germany.
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Schleh C, Hohlfeld JM. Interaction of nanoparticles with the pulmonary surfactant system. Inhal Toxicol 2009; 21 Suppl 1:97-103. [DOI: 10.1080/08958370903005744] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Christmann U, Buechner-Maxwell VA, Witonsky SG, Hite RD. Role of lung surfactant in respiratory disease: current knowledge in large animal medicine. J Vet Intern Med 2009; 23:227-42. [PMID: 19192153 DOI: 10.1111/j.1939-1676.2008.0269.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Lung surfactant is produced by type II alveolar cells as a mixture of phospholipids, surfactant proteins, and neutral lipids. Surfactant lowers alveolar surface tension and is crucial for the prevention of alveolar collapse. In addition, surfactant contributes to smaller airway patency and improves mucociliary clearance. Surfactant-specific proteins are part of the innate immune defense mechanisms of the lung. Lung surfactant alterations have been described in a number of respiratory diseases. Surfactant deficiency (quantitative deficit of surfactant) in premature animals causes neonatal respiratory distress syndrome. Surfactant dysfunction (qualitative changes in surfactant) has been implicated in the pathophysiology of acute respiratory distress syndrome and asthma. Analysis of surfactant from amniotic fluid allows assessment of fetal lung maturity (FLM) in the human fetus and exogenous surfactant replacement therapy is part of the standard care in premature human infants. In contrast to human medicine, use and success of FLM testing or surfactant replacement therapy remain limited in veterinary medicine. Lung surfactant has been studied in large animal models of human disease. However, only a few reports exist on lung surfactant alterations in naturally occurring respiratory disease in large animals. This article gives a general review on the role of lung surfactant in respiratory disease followed by an overview of our current knowledge on surfactant in large animal veterinary medicine.
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Affiliation(s)
- U Christmann
- Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Duck Pond Drive, Phase II, Blacksburg, VA 24061, USA.
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Erpenbeck VJ, Krug N, Hohlfeld JM. Therapeutic use of surfactant components in allergic asthma. Naunyn Schmiedebergs Arch Pharmacol 2008; 379:217-24. [PMID: 18854984 DOI: 10.1007/s00210-008-0354-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2008] [Accepted: 09/10/2008] [Indexed: 01/26/2023]
Abstract
Pulmonary surfactant is a complex mixture of lipids and proteins that reduces the surface tension at the air-liquid interface. In addition to its biophysical function, some surfactant components play an important role for the innate and adaptive immunity of the lung. A negative modulation of the surfactant function was observed in allergic asthma leading to the assumption that the therapeutic application of surfactant components might be beneficial in this disease. So far, there are a number of preclinical and already some clinical studies demonstrating various effects of different surfactant components that were administered with preventive or therapeutic aim in allergic asthma. This review summarizes the current knowledge on the possibilities to treat allergic asthma with surfactant components.
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Affiliation(s)
- Veit J Erpenbeck
- Fraunhofer Institute of Toxicology and Experimental Medicine, Hannover, Germany.
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Christmann U, Welles EG, Waldridge BM, Schumacher J, Grier BL, Hite RD. Abnormalities in lung surfactant in horses clinically affected with recurrent airway obstruction (RAO). J Vet Intern Med 2008; 22:1452-5. [PMID: 18761600 DOI: 10.1111/j.1939-1676.2008.0177.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Abnormalities in lung surfactant are well described in human respiratory diseases including asthma, but are poorly described in horses. HYPOTHESIS Lung surfactant is abnormal in horses with clinical signs of recurrent airway obstruction (RAO). ANIMALS Six healthy horses and 5 horses with RAO. METHODS Bronchoalveolar lavage fluid (BALF) was obtained from all horses by standard procedures. Cell-free BALF was separated into crude surfactant pellets (CSP) and supernatant via ultracentrifugation. Phospholipid and protein content was analyzed from both of these fractions. Phospholipid composition of CSP was determined using high-performance liquid chromatography with an evaporative light scatter detector. Surface tension of CSP was measured with a pulsating bubble surfactometer. RESULTS Compared with healthy horses, surfactant from RAO-affected horses was characterized by significantly decreased phospholipid content in total surfactant (median; range: 23.2; 14.7-62.2 microg/mL BALF versus 172; 111-267 microg/mL BALF, P = .0062) and CSP (20.2; 6.4-48.9 microL/mL BALF versus 155; 94.4-248 microg/mL BALF, P = .0062), and a significantly lower percentage of phosphatidylglycerol (PG) (4.5; 3.6-5.6% versus 6.6; 4.1-7.6%, P = .028). Furthermore, the ratio between the percentages of phosphatidylcholine and PG was significantly higher in RAO-affected horses than in healthy horses (20.9; 16.6: 25.9 versus 13.9; 11.8-22.8, P = .045). CONCLUSIONS AND CLINICAL IMPORTANCE This study demonstrates that surfactant from RAO-affected horses is abnormal. Further studies are needed to determine if these abnormalities are related to an increased tendency for bronchoconstriction and to a decreased ability to clear airway mucus in RAO-affected horses.
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Affiliation(s)
- U Christmann
- Department of Large Animal Clinical Sciences, Auburn University, Auburn, AL, USA.
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Abstract
Beta(2)-adrenergic agonists cause a release of pulmonary surfactant into lung airways. The surfactant phospholipids maintain the patency of the conducting airways, but this function is inhibited by plasma proteins entering an inflamed airway. The physical behavior of the surfactant can be studied with a pulsating bubble surfactometer and a capillary surfactometer. Calf lung surfactant extract was found to be inhibited by plasma proteins and by a lowering of temperature. Severe breathing difficulties and malfunctioning surfactant developed in BALB/c mice inhaling ozone or infected with respiratory syncytial virus, mainly as a result of proteins invading the airways. Patients with asthma were challenged with allergens in an area of one lung. BAL fluid (BALF) from such an area contained a surfactant that functioned poorly (ie, an inability to maintain airway openness) compared with BALF from the other lung or from the lungs of healthy volunteers. When proteins in the BALF were removed, surfactant performance clearly improved. Eosinophils, so prominent in asthmatic patients, synthesize the enzyme lysophospholipase, which, together with the enzyme phospholipase A(2), catalyzes the hydrolysis of the main component of the surfactant, phosphatidylcholine. Such hydrolysis incapacitates the ability of the surfactant to maintain airway patency. The treatment of asthma with beta(2)-adrenergic agonists and steroids will have a valuable effect on the surfactant system. It will cause a release of fresh surfactant into terminal airways. Surfactant can also be nebulized and inhaled, which has been shown to be an effective treatment.
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Affiliation(s)
- Goran Enhorning
- SUNY at Buffalo, Department of Gynecology/Obstetrics, NY 14222, USA.
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Abo M, Kurashima K, Fujimura M, Myou S, Nakao S, Tashiro K, Kobayashi T. Surfactant degradation activity in bronchoalveolar lavage fluid from guinea pigs challenged with antigen. Respirology 2008; 12:828-33. [PMID: 17986110 DOI: 10.1111/j.1440-1843.2007.01179.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Surfactant dysfunction is a characteristic of bronchial asthma, but mechanisms of dysfunction following antigen exposure are not understood. The aim of this study was to examine whether bronchoalveolar lavage fluid (BALF) has surfactant degradation activity after antigen challenge, using an animal model of asthma. METHODS BALF was collected 24 h after a challenge with aerosolized antigen solution in actively sensitized guinea pigs and from non-sensitized control guinea pigs. The surface tension of BALF was measured by pulsating bubble surfactometer. Surfactant activity was expressed as the minimum surface tension of BALF after 5 min of pulsation. BALF was separated into a cellular phospholipid fraction and supernatant, and reconstituted into 'pellet + supernatant' and 'pellet + saline' fractions. RESULTS Surfactant activity of BALF from sensitized antigen-challenged animals was reduced after 4 h of incubation at 37 degrees C but a decrease was not observed in BALF from non-sensitized control animals. The decrease of surfactant activity in BALF from challenged animals was prevented by incubation at 4 degrees C. Disappearance of surfactant activity after incubation at 37 degrees C was observed in the 'pellet + supernatant', but not in the 'pellet + saline' fraction. The decrease of surfactant activity in BALF was also partially suppressed by the secretory phospholipase A2 inhibitor, indoxam, and by a cocktail of protease inhibitors. CONCLUSION Surfactant-degrading activity was present in the supernatant of BALF from antigen-challenged guinea pigs. This activity may be attributed to secretory phospholipase A2 and to proteases present in the antigen-challenged airway.
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Affiliation(s)
- Miki Abo
- Department of Respiratory and Hematology Medicine, Cellular Transplantation Biology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
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Acoustically detectable cellular-level lung injury induced by fluid mechanical stresses in microfluidic airway systems. Proc Natl Acad Sci U S A 2007; 104:18886-91. [PMID: 18006663 DOI: 10.1073/pnas.0610868104] [Citation(s) in RCA: 311] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We describe a microfabricated airway system integrated with computerized air-liquid two-phase microfluidics that enables on-chip engineering of human airway epithelia and precise reproduction of physiologic or pathologic liquid plug flows found in the respiratory system. Using this device, we demonstrate cellular-level lung injury under flow conditions that cause symptoms characteristic of a wide range of pulmonary diseases. Specifically, propagation and rupture of liquid plugs that simulate surfactant-deficient reopening of closed airways lead to significant injury of small airway epithelial cells by generating deleterious fluid mechanical stresses. We also show that the explosive pressure waves produced by plug rupture enable detection of the mechanical cellular injury as crackling sounds.
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Kendall M. Fine airborne urban particles (PM2.5) sequester lung surfactant and amino acids from human lung lavage. Am J Physiol Lung Cell Mol Physiol 2007; 293:L1053-8. [PMID: 17616648 DOI: 10.1152/ajplung.00131.2007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Components of surfactant act as opsonins and enhance phagocytosis of bacteria; whether this process occurs with atmospheric fine particles has not been shown. We have studied the interactions of fine particles (urban PM2.5) and surfactant removed from normal human lungs by lavage, using a surface analysis technique. The aim was to identify which of the chemical components of brochoalveolar lavage (BAL) deposit on the surfaces of urban PM2.5. Deposition of surfactant components on urban PM2.5 surfaces was reported in previous studies, but molecular identification and relative quantification was not possible using simple data analysis. In this study, we were able to identify adsorbed components by applying an appropriate statistical technique, factor analysis. In this study, the most strongly associated mass fragment on PM2.5 surfaces exposed to BAL (and undetected on both untreated samples and saline controls) was di-palmitoyl-phosphatidylcholine, a component of lung surfactant. Amino acids were also strongly associated with BAL-exposed PM2.5 surfaces and not other sample types. Thirteen mass fragments were identified, diagnostic of the amino acids alanine, arginine, asparagine, aspartic acid, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, serine, and valine. This study provides evidence that lung surfactant and amino acids related to opsonin proteins adsorb to nonbiological particle surfaces exposed to human lung lining fluid. Disruption of normal surfactant function, both physical and immunological, is possible but unproven. Further work on this PM-opsonin interaction is recommended.
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Nag K, Hillier A, Parsons K, Garcia MF. Interactions of serum with lung surfactant extract in the bronchiolar and alveolar airway models. Respir Physiol Neurobiol 2007; 157:411-24. [PMID: 17350899 DOI: 10.1016/j.resp.2007.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 01/24/2007] [Accepted: 02/02/2007] [Indexed: 11/25/2022]
Abstract
Lung surfactant (LS) a lipid-protein mixture is secreted by type-II pneumocytes and prevents alveolar collapse as well as maintains upper airway patency. In certain lung pathophysiology dysfunction of the LS occurs due to leakage of serum derived materials interacting with surfactant at the respiratory air-water interface. Bovine lipid extract surfactant (BLES) with and without foetal calf serum (FCS) were studied as models of bronchiolar airway patency using a capillary surfactometer, and in alveolar (terminal) airway using adsorbed Langmuir films in a surface balance. About 5 wt.% of serum was found to maximally decrease airway patency of BLES by 90%, as well as the surface films ability to reach low surface tension below 25 mN/m. In fact, FCS was found to be about 200-fold more potent inhibitor of the surfactant extract compared to a major serum component, albumin. Also serum but not albumin significantly reduced the gel-phase structures found in BLES films under compression at low amounts (5-10 wt.%), and eventually abolished these organized structures as imaged by fluorescence and atomic force microscopy. This fact suggests that serum caused complete molecular re-organization of the surfactant lipids in films at an air-water interface, and the ability of such films to reduce surface tension or maintain airway patency. The study may provide a novel structure-function disruption model for lung surfactant inactivation in the airways in pathophysiology.
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Affiliation(s)
- Kaushik Nag
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X9.
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Strüber M, Fischer S, Niedermeyer J, Warnecke G, Gohrbandt B, Görler A, Simon AR, Haverich A, Hohlfeld JM. Effects of exogenous surfactant instillation in clinical lung transplantation: a prospective, randomized trial. J Thorac Cardiovasc Surg 2007; 133:1620-5. [PMID: 17532965 DOI: 10.1016/j.jtcvs.2006.12.057] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Revised: 12/10/2006] [Accepted: 12/14/2006] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Despite the introduction of low potassium-based preservation strategies for clinical lung transplantation, relevant early graft dysfunction occurs in up to 20% of cases after lung transplantation. This was found to be frequently associated with postreperfusion surfactant dysfunction. We performed a randomized, prospective study investigating the effect of exogenous surfactant instillation into human donor lungs on posttransplant surfactant function and on clinical outcome. METHODS Exogenous surfactant was instilled into 15 donor lungs before retrieval via bronchoscopy. Bronchoalveolar lavage fluids were taken before instillation as well as 24 hours after transplantation. Surfactant function, phospholipids, and protein content in bronchoalveolar lavage fluids were assessed and clinical data prospectively recorded. Pulmonary function testing was performed 4 weeks after lung transplantation. Additionally, the best forced expiratory volume in 1 second was determined within the first year after lung transplantation. The control group consisted of 14 patients receiving donor lungs without surfactant instillation in randomized order. Pulmonary function test results were further compared with those of 154 consecutive recipients of bilateral lung transplants, which were not involved in the study (historical control). RESULTS No deaths occurred during the first year after lung transplantation. Surfactant function in donor lungs was within normal ranges before harvest. In the control group, surfactant function was markedly impaired after reperfusion. This was significantly improved by surfactant substitution. Protein content of the bronchoalveolar lavage fluid in the surfactant group was significantly lower, indicating less leakage through the alveolocapillary membrane. Forced expiratory volume in 1 second after 4 weeks was significantly higher in the surfactant group than in either control group (P = .034 and .01, respectively). Interestingly, the best forced expiratory volume in 1 second during the first year after lung transplantation was significantly higher in both control groups compared with forced expiratory volume measured in examinations 4 weeks after lung transplantation (P = .01). The best forced expiratory volumes in 1 second of control patients were comparable with those in surfactant lungs 4 weeks after transplant. CONCLUSIONS This study indicates a protective effect of exogenous surfactant instillation to donor lungs before retrieval on post-lung transplantation surfactant function and on early clinical outcome. This approach may help to improve the outcome after lung transplantation in the future.
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Affiliation(s)
- Martin Strüber
- Hannover Thoracic Transplant Program, Division of Thoracic and Cardiovascular Surgery, Hannover Medical School, Hannover, Germany.
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Kwatia MA, Doyle CB, Cho W, Enhorning G, Ackerman SJ. Combined activities of secretory phospholipases and eosinophil lysophospholipases induce pulmonary surfactant dysfunction by phospholipid hydrolysis. J Allergy Clin Immunol 2007; 119:838-47. [PMID: 17321580 DOI: 10.1016/j.jaci.2006.12.614] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 11/29/2006] [Accepted: 12/11/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Surfactant dysfunction is implicated in small airway closure in asthma. Increased activity of secretory phospholipase A(2) (sPLA(2)) in the airways is associated with asthma exacerbations. Phosphatidylcholine, the principal component of pulmonary surfactant that maintains small airway patency, is hydrolyzed by sPLA(2). The lysophosphatidylcholine product is the substrate for eosinophil lysophospholipases. OBJECTIVE To determine whether surfactant phospholipid hydrolysis by the combined activities of sPLA(2)s and eosinophil lysophospholipases induces surfactant dysfunction. METHODS The effect of these enzymes on surfactant function was determined by capillary surfactometry. Thin layer chromatography was used to correlate enzyme-induced changes in surfactant phospholipid composition and function. Phosphatidylcholine and its hydrolytic products were measured by using mass spectrometry. RESULTS Eosinophils express a 25-kd lysophospholipase and group IIA sPLA(2). Phospholipase A(2) alone induced only a small decrease in surfactant function, and 25-kd lysophospholipase alone degraded lysophosphatidylcholine but had no effect on surfactant function. The combined actions of sPLA(2) and lysophospholipase produced dose-dependent and time-dependent losses of surfactant function, concomitant with hydrolysis of phosphatidylcholine and lysophosphatidylcholine. Lysates of AML14.3D10 eosinophils induced surfactant dysfunction, indicating these cells express all the necessary lipolytic activities. In contrast, lysates of blood eosinophils required exogenous phospholipase A(2) to induce maximal surfactant dysfunction. CONCLUSION The combined activities of sPLA(2)s and eosinophil lysophospholipases are necessary to degrade surfactant phospholipids sufficiently to induce functional losses in surfactant activity as reported in asthma. CLINICAL IMPLICATIONS The phospholipases and lysophospholipases expressed by eosinophils or other airway cells may represent novel therapeutic targets for blocking surfactant degradation, dysfunction, and peripheral airway closure in asthma.
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Affiliation(s)
- Mark A Kwatia
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607-7170, USA
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Lundblad LKA, Thompson-Figueroa J, Allen GB, Rinaldi L, Norton RJ, Irvin CG, Bates JHT. Airway hyperresponsiveness in allergically inflamed mice: the role of airway closure. Am J Respir Crit Care Med 2007; 175:768-74. [PMID: 17255559 PMCID: PMC1899295 DOI: 10.1164/rccm.200610-1410oc] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Allergically inflamed mice exhibit airway hyperresponsiveness to inhaled methacholine, which computer simulations of lung impedance suggest is due to enhanced lung derecruitment and which we sought to verify in the present study. METHODS BALB/c mice were sensitized and challenged with ovalbumin to induce allergic inflammation; the control mice were sensitized but received no challenge. The mice were then challenged with inhaled methacholine and respiratory system impedance tracked for the following 10 minutes. Respiratory elastance (H) was estimated from each impedance measurement. One group of mice was ventilated with 100% O(2) during this procedure and another group was ventilated with air. After the procedure, the mice were killed and ventilated with pure N(2), after which the trachea was tied off and the lungs were imaged with micro-computed tomography (micro-CT). RESULTS H was significantly higher in allergic mice than in control animals after methacholine challenge. The ratio of H at the end of the measurement period between allergic and nonallergic mice ventilated with O(2) was 1.36, indicating substantial derecruitment in the allergic animals. The ratio between lung volumes determined by micro-CT in the control and the allergic mice was also 1.36, indicative of a corresponding volume loss due to absorption atelectasis. Micro-CT images and histograms of Hounsfield units from the lungs also showed increased volume loss in the allergic mice compared with control animals after methacholine challenge. CONCLUSIONS These results support the conclusion that airway closure is a major component of hyperresponsiveness in allergically inflamed mice.
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Affiliation(s)
- Lennart K A Lundblad
- Vermont Lung Center, The University of Vermont College of Medicine, HSRF 230, 149 Beaumont Avenue, Burlington, VT 05405-0075, USA.
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Siegle JS, Hansbro N, Herbert C, Yang M, Foster PS, Kumar RK. Airway hyperreactivity in exacerbation of chronic asthma is independent of eosinophilic inflammation. Am J Respir Cell Mol Biol 2006; 35:565-70. [PMID: 16794258 DOI: 10.1165/rcmb.2006-0135oc] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We have developed an animal model to investigate the mechanisms underlying an acute exacerbation of chronic asthma. Sensitized BALB/c mice were exposed to aerosolized ovalbumin, either as chronic low-level challenge (mass concentration approximately 3 mg/m(3)) for 4 wk, a single moderate-level challenge (approximately 30 mg/m(3)), or chronic low-level followed by single moderate-level challenge (the acute exacerbation group). Compared with animals receiving chronic challenge alone, mice in the acute exacerbation group exhibited a more marked inflammatory response, with involvement of intrapulmonary airways and lung parenchyma, and increased numbers of lymphocytes and eosinophils in bronchoalveolar lavage fluid. They also developed airway hyperreactivity (AHR) to methacholine, demonstrable as increased transpulmonary resistance and decreased compliance. This pattern of AHR was absent in chronically challenged animals, but was also present in animals given single moderate-level challenge. However, compared with animals receiving a single moderate-level challenge, inflammation and AHR were induced more rapidly in the acute exacerbation group. Eosinophil-deficient GATA1 Deltadbl mice exhibited undiminished AHR in the acute exacerbation model. We conclude that in mice with pre-existing airway lesions resembling mild chronic asthma, exposure to a moderately high concentration of inhaled antigen induces features of an acute exacerbation. The inflammatory response involves distal airways and is associated with a distinct pattern of AHR, which develops independent of the enhanced eosinophilic inflammation.
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Affiliation(s)
- Jessica S Siegle
- Department of Pathology, University of New South Wales, Sydney, Australia
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Erpenbeck VJ, Schmidt R, Günther A, Krug N, Hohlfeld JM. Surfactant protein levels in bronchoalveolar lavage after segmental allergen challenge in patients with asthma. Allergy 2006; 61:598-604. [PMID: 16629790 DOI: 10.1111/j.1398-9995.2006.01062.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Allergic asthma is associated with airway inflammation and dysfunction of pulmonary surfactant. Because surfactant proteins (SP) account for immunomodulatory functions as well as biophysical functions, we hypothesized that the allergic response in asthma might be accompanied by a dysregulation of SPs. METHODS We measured levels of SP-A, SP-B, SP-C and SP-D by enzyme-linked immunosorbent assay in bronchoalveolar lavage (BAL) fluid of 23 asthma patients and 10 healthy control subjects under well-controlled conditions before and 24 h after segmental allergen provocation. These data were related to surfactant function, Th(2) cytokine levels in BAL fluid and to the degree of eosinophilic inflammation. RESULTS In patients with asthma, allergen challenge increased BAL levels of SP-B, SP-C and SP-D while SP-A was decreased. For SP-B and SP-D, a moderate increase was also observed after saline challenge. In contrast, no alterations were observed in healthy control subjects. Levels of SP-B and SP-C in asthmatics correlated with the ratio of small to large surfactant aggregates (SA/LA ratio) and correlated negatively with BAL surface activity. Furthermore, increased SP-C but not SP-B levels after allergen challenge correlated with eosinophil numbers, interleukin (IL)-5, and IL-13 in BAL while increased SP-D levels only correlated with eosinophil numbers. CONCLUSIONS This study demonstrates significant alterations of all SPs in BAL fluid after allergen challenge of which SP-C was most closely related to surfactant dysfunction and the degree of the allergic inflammation.
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Affiliation(s)
- V J Erpenbeck
- Fraunhofer Institute of Toxicology and Experimental Medicine, Hannover, Germany
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Lee YS, Chen PW, Tsai PJ, Su SH, Liao PC. Proteomics analysis revealed changes in rat bronchoalveolar lavage fluid proteins associated with oil mist exposure. Proteomics 2006; 6:2236-50. [PMID: 16518868 DOI: 10.1002/pmic.200500347] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Exposure to oil mist has been associated with a variety of acute and chronic respiratory effects. Using proteomics approaches to investigate exposure-associated proteins may provide useful information to understand the mechanisms of associated respiratory effects. The aim of this study was to investigate changes in rat bronchoalveolar lavage fluid proteins associated with oil mist exposure using nano-HPLC-ESI-MS/MS. The results revealed that 29 proteins exhibited significant changes after exposure. These proteins included surfactant-associated proteins (SP-A and SP-D), inflammatory proteins (complement component 3, immunoglobulins, lysozyme, etc.), growth factors (e.g., transforming growth factor alpha (TGF-alpha)), calcium-binding proteins (calcyclin, calgranulin A, calreticulin, and calvasculin), and other proteins (e.g., cathepsin D, saposin, and intestinal trefoil factor). To further evaluate changes in protein levels, a simple quantitative strategy was developed in this study. A large decrease in protein levels of SP-A and SP-D (0.24- and 0.38-fold, respectively) following exposure was observed. In contrast, protein levels of TGF-alpha and calcium-binding proteins were significantly increased (4.46- and 1.4-1.8-fold, respectively). Due to the diverse functions of these proteins, the results might contribute to understand the mechanisms involved in lung disorders induced by oil mist exposure.
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Affiliation(s)
- Yung-Shan Lee
- Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Bates JHT, Allen GB. The estimation of lung mechanics parameters in the presence of pathology: a theoretical analysis. Ann Biomed Eng 2006; 34:384-92. [PMID: 16468093 DOI: 10.1007/s10439-005-9056-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Accepted: 10/13/2005] [Indexed: 11/24/2022]
Abstract
Mechanical lung function is frequently assessed in terms of lung resistance (R (L)), lung elastance (E (L)), and airway resistance (R (aw)). These quantities are determined by measuring input impedance at various oscillation frequencies, and allow lung tissue resistance (R (t)) to be estimated as the difference between R (L) and R (aw). These various parameters change in characteristic ways in the presence of lung pathology. In particular, the ratio R (t)/E (L) (known as hysteresivity, (eta) has been shown both experimentally and in numerical simulations to increase when regional heterogeneities in mechanical function develop throughout the lung. In this study, we performed an analytical investigation of a two-compartment lung model and showed that while heterogeneity always leads to an increase in E (L), eta will increase only initially. When heterogeneity becomes extreme, eta stops increasing and starts to decrease. However, there are no experimental reports of eta decreasing under conditions in which heterogeneity would be expected to exist. We speculate that this is because liquid bridges invariably form across airway lumen that narrow to a certain point, thereby preventing them from achieving arbitrarily small non-zero radii. We also show that recruitment of closed lung units during lung inflation may lead to variables responses in both eta and E (L).
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Affiliation(s)
- Jason H T Bates
- Vermont Lung Center Departments of Medicine and Molecular Physiology and Biophysics, University of Vermont Burlington, Burlington, VT 05405-0075, USA.
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Hite RD, Seeds MC, Jacinto RB, Grier BL, Waite BM, Bass DA. Lysophospholipid and fatty acid inhibition of pulmonary surfactant: non-enzymatic models of phospholipase A2 surfactant hydrolysis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1720:14-21. [PMID: 16376294 DOI: 10.1016/j.bbamem.2005.10.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2004] [Revised: 10/24/2005] [Accepted: 10/28/2005] [Indexed: 10/25/2022]
Abstract
Secretory A(2) phospholipases (sPLA(2)) hydrolyze surfactant phospholipids cause surfactant dysfunction and are elevated in lung inflammation. Phospholipase-mediated surfactant hydrolysis may disrupt surfactant function by generation of lysophospholipids and free fatty acids and/or depletion of native phospholipids. In this study, we quantitatively assessed multiple mechanisms of sPLA(2)-mediated surfactant dysfunction using non-enzymatic models including supplementation of surfactants with exogenous lysophospholipids and free fatty acids. Our data demonstrated lysophospholipids at levels >or=10 mol% of total phospholipid (i.e., >or=10% hydrolysis) led to a significant increase in minimum surface tension and increased the time to achieve a normal minimum surface tension. Lysophospholipid inhibition of surfactant function was independent of the lysophospholipid head group or total phospholipid concentration. Free fatty acids (palmitic acid, oleic acid) alone had little effect on minimum surface tension, but did increase the maximum surface tension and the time to achieve normal minimum surface tension. The combined effect of equimolar free fatty acids and lysophospholipids was not different from the effect of lysophospholipids alone for any measurement of surfactant function. Surfactant proteins did not change the percent lysophospholipids required to increase minimum surface tension. As a mechanism that causes surfactant dysfunction, depletion of native phospholipids required much greater change (equivalent to >80% hydrolysis) than generation of lysophospholipids. In summary, generation of lysophospholipids is the principal mechanism of phospholipase-mediated surfactant injury in our non-enzymatic models. These models and findings will assist in understanding more complex in vitro and in vivo studies of phospholipase-mediated surfactant injury.
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Affiliation(s)
- R Duncan Hite
- Department of Internal Medicine, Section on Pulmonary and Critical Care, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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Schmiedl A, Tschernig T, Brasch F, Pabst R, Bargsten G. Decrease of the surface fraction of surfactant proteins containing clara cells and type II pneumocytes in a rat asthma model. ACTA ACUST UNITED AC 2005; 56:265-72. [PMID: 15816355 DOI: 10.1016/j.etp.2004.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In asthma surfactant proteins (SP) might differ in distribution and composition and thus play a role in pathophysiology of this disease. Therefore, the well-established animal model of ovalbumin sensitized and challenged rats were used to study the distribution of surfactant proteins in Clara cells and type II pneumocytes. Serial sections of paraffin embedded lung tissue were sequentially immunostained by the avidin-biotin-peroxidase complex (ABC) technique. Antisera against SP-A, SP-B and Clara cell specific protein (CC10) were used. We determined stereologically' the surface fraction of immunolabelled cells and semiquantitatively the percentage of test fields containing labelled alveolar macrophages. In allergen sensitized and provocated rat lungs: (1) the surface fraction of SP-A and SP-B positive Clara cells was significantly reduced, (2) the surface fraction of Clara cells stained with CC10 was coincided with controls, (3) the surface fraction of SP-A and not of SP-B possitive type II pneumocytes decreased significantly, (4) a significantly higher percentage of test fields with SP-A labelled alveolar macrophages was evaluated. Thus, in this animal model of asthma the inflammatory process after allergen challenge is accompanied by alterations in the distribution patterns of SP in Clara cells and type II pneumocytes.
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Affiliation(s)
- Andreas Schmiedl
- Department I, Centre of Anatomy, Hannover Medical School, Hannover, Germany.
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Bowton DL, Dmitrienko AA, Israel E, Zeiher BG, Sides GD. Impact of a soluble phospholipase A2 inhibitor on inhaled allergen challenge in subjects with asthma. J Asthma 2005; 42:65-71. [PMID: 15801331 DOI: 10.1081/jas-200044748] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The possible roles of secretory phospholipases A2 (sPLA2) in asthma include the release of arachidonic acid from cellular membranes, generation of lysophospholipids, sPLA2-mediated activation of cPLA2 with increased leukotriene production, and surfactant degradation. LY333013 is a potent inhibitor of sPLA2. This study examined the impact of two doses of LY333013 vs. placebo on allergen-induced bronchoconstriction following inhaled allergen challenge in atopic asthmatics. Fifty subjects were randomly assigned to treatment, and 40 subjects completed the study. A double-blind, placebo-controlled, random order, crossover study design was used. LY333013 had no impact on the primary outcome variables of the areas under the FEV1 response curve early (0-3 hours) (AUC(early)) and late (3-8 hours) (AUC(Iate)) following inhaled allergen challenge. No significant drug-related adverse effects were observed. The response to inhaled allergen challenge was reproducible and confirms the utility of this technique as a model in which to screen compounds for further testing in asthmatic patients.
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Affiliation(s)
- David L Bowton
- Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1009, USA.
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Hite RD, Seeds MC, Bowton DL, Grier BL, Safta AM, Balkrishnan R, Waite BM, Bass DA. Surfactant phospholipid changes after antigen challenge: a role for phosphatidylglycerol in dysfunction. Am J Physiol Lung Cell Mol Physiol 2004; 288:L610-7. [PMID: 15347567 DOI: 10.1152/ajplung.00273.2004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In asthma, inflammation-mediated surfactant dysfunction contributes to increased airway resistance, but the mechanisms for dysfunction are not understood. To test mechanisms that alter surfactant function, atopic asthmatics underwent endobronchial antigen challenge and bronchoalveolar lavage (BAL). BAL fluids were sequentially separated into cells, surfactant, and supernatant, and multiple end points were analyzed. Each end point's unique relationship to surfactant dysfunction was determined. Our results demonstrate that minimum surface tension (gamma(min)) of surfactant after antigen challenge was significantly increased with a spectrum of responses that included dysfunction in 6 of 13 asthmatics. Antigen challenge significantly altered the partitioning of surfactant phospholipid measured as a decreased ratio of large surfactant aggregates (LA) to small surfactant aggregates (SA), LA/SA ratio. Phosphatidylglycerol (PG) was significantly reduced in the LA of the dysfunctional asthmatic BALs. There was a corresponding significant increase in the ratio of phosphatidylcholine to PG, which strongly correlated with both increased gamma(min) and decreased LA/SA. Altered surfactant phospholipid properties correlated with surfactant dysfunction as well or better than either increased eosinophils or protein. Secretory phospholipase activity, measured in vitro, increased after antigen challenge and may explain the decrease in surfactant PG. In summary, alteration of phospholipids, particularly depletion of PG, in the LA of surfactant may be an important mechanism in asthma-associated surfactant dysfunction.
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Affiliation(s)
- R Duncan Hite
- Section of Pulmonary Medicine, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1054, USA.
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Braun A, Steinecker M, Schumacher S, Griese M. Surfactant function in children with chronic airway inflammation. J Appl Physiol (1985) 2004; 97:2160-5. [PMID: 15310745 DOI: 10.1152/japplphysiol.00523.2004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary surfactant is necessary to keep the terminal conducting airways patent. It is unknown whether mild to moderate airway inflammation may influence surfactant function and thus contribute to the pathogenesis of chronic airway inflammation in children. To answer this question, 21 children with chronic obstructive bronchitis and 19 asymptomatic children with long-term tracheostomy and increased numbers of neutrophils in their airways were compared with 15 healthy controls. Bronchoalveolar lavage fluid was separated into large surfactant aggregates (LA) and a supernatant containing inhibitory constituents. Surfactant function of LA, recombinations of LA and supernatant, and recombinations of a defined bovine surfactant and supernatant was assessed in a capillary surfactometer. Compared with controls, the function of the LA surfactant was reduced and there was no difference between children with tracheostomy and chronic obstructive bronchitis. The function of LA-supernatant recombinations was poor in all subjects. This may be explained by the well-known protein influx during the lavage procedure. The activity of bovine surfactant-supernatant reconstitutions was impaired in children with tracheostomy. In all surfactant mixtures assessed, surfactant function was inversely correlated to the number of neutrophils in the lavage fluid. Chronic lower airway inflammation with mild or no clinical symptoms is associated with impaired surfactant function. The dysfunction may contribute to airflow restrictions frequently observed in these children.
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Affiliation(s)
- A Braun
- Children's Hospital, Ludwig Maximilians University, Lindwurmstrasse 4, 80337 Munich, Germany
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Hohlfeld JM, Schmiedl A, Erpenbeck VJ, Venge P, Krug N. Eosinophil cationic protein alters pulmonary surfactant structure and function in asthma. J Allergy Clin Immunol 2004; 113:496-502. [PMID: 15007353 DOI: 10.1016/j.jaci.2003.12.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Impaired surfactant function has been demonstrated in patients with asthma. Inhibitory proteins originating from plasma or inflammatory mediators are good candidates to contribute to this dysfunction. Eosinophils are potent effector cells in asthma, which, on activation, release inflammatory mediators, especially reactive granula proteins such as eosinophil cationic protein (ECP). OBJECTIVE Because the potential role of ECP in the inhibition of surfactant function is not known, we tested the hypothesis of whether ECP levels in bronchoalveolar lavage fluid (BALF) of patients with asthma after segmental allergen provocation correlate to surfactant dysfunction. Furthermore, we tested the effect of purified ECP on surfactant function and structure in vitro. METHODS Surfactant isolated from BALF of asthmatic patients was assessed for biophysical function with the Pulsating Bubble Surfactometer and the Capillary Surfactometer and correlated to ECP levels. Purified ECP and plasma proteins at various concentrations were incubated with natural surfactant. Surfactant function was studied with the Capillary Surfactometer, and surfactant structure was determined by electron microscopy. RESULTS ECP is elevated in BALF from patients with asthma after allergen challenge compared with baseline. ECP levels after allergen challenge correlate well to surfactant dysfunction. In vitro, ECP induces a concentration-dependent inhibition of surfactant function that can be inhibited by antibodies against ECP. ECP is more potent compared with albumin or fibrinogen. Finally, ECP induces severe ultrastructural changes to surfactant vesicles that are more pronounced than changes induced by either fibrinogen or albumin. CONCLUSIONS ECP contributes to surfactant dysfunction in asthma, which in turn could lead to airway obstruction.
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Affiliation(s)
- Jens M Hohlfeld
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
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Baritussio A. Lung surfactant, asthma, and allergens: a story in evolution. Am J Respir Crit Care Med 2004; 169:550-1. [PMID: 14982818 DOI: 10.1164/rccm.2312019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Scott JE. The pulmonary surfactant: impact of tobacco smoke and related compounds on surfactant and lung development. Tob Induc Dis 2004; 2:3-25. [PMID: 19570267 PMCID: PMC2671518 DOI: 10.1186/1617-9625-2-1-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cigarette smoking, one of the most pervasive habits in society, presents many well established health risks. While lung cancer is probably the most common and well documented disease associated with tobacco exposure, it is becoming clear from recent research that many other diseases are causally related to smoking. Whether from direct smoking or inhaling environmental tobacco smoke (ETS), termed secondhand smoke, the cells of the respiratory tissues and the lining pulmonary surfactant are the first body tissues to be directly exposed to the many thousands of toxic chemicals in tobacco. Considering the vast surface area of the lung and the extreme attenuation of the blood-air barrier, it is not surprising that this organ is the primary route for exposure, not just to smoke but to most environmental contaminants. Recent research has shown that the pulmonary surfactant, a complex mixture of phospholipids and proteins, is the first site of defense against particulates or gas components of smoke. However, it is not clear what effect smoke has on the surfactant. Most studies have demonstrated that smoking reduces bronchoalveolar lavage phospholipid levels. Some components of smoke also appear to have a direct detergent-like effect on the surfactant while others appear to alter cycling or secretion. Ultimately these effects are reflected in changes in the dynamics of the surfactant system and, clinically in changes in lung mechanics. Similarly, exposure of the developing fetal lung through maternal smoking results in postnatal alterations in lung mechanics and higher incidents of wheezing and coughing. Direct exposure of developing lung to nicotine induces changes suggestive of fetal stress. Furthermore, identification of nicotinic receptors in fetal lung airways and corresponding increases in airway connective tissue support a possible involvement of nicotine in postnatal asthma development. Finally, at the level of the alveoli of the lung, colocalization of nicotinic receptors and surfactant-specific protein in alveolar cells is suggestive of a role in surfactant metabolism. Further research is needed to determine the mechanistic effects of smoke and its components on surfactant function and, importantly, the effects of smoke components on the developing pulmonary system.
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Affiliation(s)
- J Elliott Scott
- Lung Development Section, Biology of Breathing Group, Manitoba Institute of Child Health & Departments of Oral Biology and Anatomy, Faculties of Dentistry and Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
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Erpenbeck VJ, Hagenberg A, Dulkys Y, Elsner J, Bälder R, Krentel H, Discher M, Braun A, Krug N, Hohlfeld JM. Natural Porcine Surfactant Augments Airway Inflammation after Allergen Challenge in Patients with Asthma. Am J Respir Crit Care Med 2004; 169:578-86. [PMID: 14644929 DOI: 10.1164/rccm.200301-104oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
There is increasing evidence for a role of pulmonary surfactant in asthma and allergic inflammation. In murine asthma models, recent studies have demonstrated that surfactant components downregulate the allergic inflammation. Therefore, we tested the hypothesis that in individuals with mild asthma, a natural porcine surfactant preparation (Curosurf) given before segmental allergen challenge can reduce the allergic airway inflammation. Ten patients with asthma and five healthy control subjects were treated in two segments with either Curosurf or vehicle followed by local allergen challenge. Six additional patients with asthma received Curosurf before allergen challenge in one segment as above, but the second segment was instilled with Curosurf without allergen challenge. Unexpectedly, surfactant treatment augmented the eosinophilic inflammation 24 hours after allergen challenge. A direct chemotactic effect of Curosurf was excluded. However, levels of eotaxin and interleukin-5 were increased in bronchoalveolar lavage after Curosurf treatment, whereas IFN-gamma-levels and numbers of IFN-gamma(+) T cells were decreased. Curosurf had no influence on spreading and retention of allergen determined by allergen uptake in mice. These findings demonstrate that treatment with a natural porcine surfactant results in an augmentation of the eosinophilic inflammation after allergen challenge that is more likely due to immunomodulatory effects than to biophysical properties of the surfactant.
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MESH Headings
- Adolescent
- Adult
- Aged
- Allergens/adverse effects
- Allergens/immunology
- Asthma/immunology
- Biological Products/adverse effects
- Biological Products/immunology
- Bronchial Hyperreactivity/immunology
- Bronchial Provocation Tests
- Bronchoalveolar Lavage Fluid/chemistry
- Bronchoalveolar Lavage Fluid/immunology
- Case-Control Studies
- Chemokine CCL11
- Chemokines, CC/analysis
- Chemokines, CC/immunology
- Disease Models, Animal
- Enzyme-Linked Immunosorbent Assay
- Eosinophils/drug effects
- Eosinophils/immunology
- Female
- Flow Cytometry
- Humans
- Inflammation
- Interferon-gamma/analysis
- Interferon-gamma/drug effects
- Interferon-gamma/immunology
- Interleukin-5/analysis
- Interleukin-5/immunology
- Male
- Middle Aged
- Phospholipids/adverse effects
- Phospholipids/immunology
- Receptors, CCR3
- Receptors, CCR5/analysis
- Receptors, CCR5/drug effects
- Receptors, CCR5/immunology
- Receptors, Chemokine/analysis
- Receptors, Chemokine/drug effects
- Receptors, Chemokine/immunology
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
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Affiliation(s)
- Veit J Erpenbeck
- Fraunhofer Institute of Toxicology and Experimental Medicine, Germany
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Abstract
Pulmonary surfactant is a mixture of lipids, mostly phospholipids, and proteins that allows for breathing with minimal effort. The current chapter discusses the metabolism of the phospholipids of this material. Surfactant phospholipids are synthesized in the type II epithelial cells of the lung. The lipids and surfactant proteins are assembled in intracellular storage organelles, called lamellar bodies, and are subsequently secreted into the alveolar space. Within this extracellular space surfactant undergoes several transformations. First the lamellar bodies unravel to form a highly organized lattice-like lipid:protein structure tubular myelin. Second, the organized structures, in particular tubular myelin, adsorb to form a lipid at the air-liquid interface of the alveoli. It is, in fact, this surface tension reducing film that is responsible for the physiological role of surfactant, to prevent lung collapse and allow ease of inflation. Third, the surface film is converted to a small vesicular form. Finally, these small vesicles are taken-up by the type II cells for recycling and degradation and by alveolar macrophages for degradation.
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Affiliation(s)
- Ruud Veldhuizen
- Departments of Medicine and Physiology and Pharmacology, Lawson Health Research Institute, London, ON, N6A 4V2, Canada
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Emerson M, Renwick L, Tate S, Rhind S, Milne E, Painter HA, Boyd AC, McLachlan G, Griesenbach U, Cheng SH, Gill DR, Hyde SC, Baker A, Alton EW, Porteous DJ, Collie DDS. Transfection efficiency and toxicity following delivery of naked plasmid DNA and cationic lipid–DNA complexes to ovine lung segments. Mol Ther 2003; 8:646-53. [PMID: 14529838 DOI: 10.1016/s1525-0016(03)00233-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We defined, using a novel large animal model system, the acute pathologic response to localized pulmonary administration of either naked plasmid DNA (pDNA) or cationic lipid-pDNA complexes (pDNA:GL67) and related such responses to concomitant indicators of transfection efficiency, namely levels of chloramphenicol acetyl transferase (CAT) protein and mRNA in specific lung tissue compartments. We instilled doses of 0.2, 1, and 5 mg pDNA to spatially distinct lung segments in six anesthetized sheep and doses of 0.2, 1, and 5 mg pDNA:GL67 to a further six sheep. Twenty-four hours after gene delivery the sheep were euthanized and necropsy examination with sampling of relevant tissues was carried out. Levels of plasmid-derived CAT-specific mRNA and CAT protein in samples derived from segments treated with either pDNA or pDNA:GL67 increased in relation to the administered dose. Levels of mRNA and protein expression were greater for pDNA:GL67 than for pDNA alone. A significant correlation was observed between mRNA and protein expression in samples derived from airways treated with pDNA:GL67. Histopathological changes following administration of both pDNA and pDNA:GL67 were characterized by a neutrophilic inflammation predominantly oriented on airways. The severity of the inflammatory response appeared to correlate with the administered dose of DNA and was generally more severe for pDNA:GL67.
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Affiliation(s)
- Michael Emerson
- Medical Genetics Section, School of Molecular & Clinical Medicine, and Department of Veterinary Pathology, College of Medicine and Veterinary Medicine, University of Edinburg, Edinburgh EH8 9AG, United Kingdom
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