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Bastani MN, Jalilian S. Unraveling the enigma: The emerging significance of pulmonary surfactant proteins in predicting, diagnosing, and managing COVID-19. Immun Inflamm Dis 2024; 12:e1302. [PMID: 38860749 PMCID: PMC11165688 DOI: 10.1002/iid3.1302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/23/2024] [Accepted: 05/19/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND Severe cases of COVID-19 often lead to the development of acute respiratory syndrome, a critical condition believed to be caused by the harmful effects of SARS-CoV-2 on type II alveolar cells. These cells play a crucial role in producing pulmonary surfactants, which are essential for proper lung function. Specifically focusing on surfactant proteins, including Surfactant protein A (SP-A), Surfactant protein B, Surfactant protein C, and Surfactant protein D (SP-D), changes in the levels of pulmonary surfactants may be a significant factor in the pathological changes seen in COVID-19 infection. OBJECTIVE This study aims to gain insights into surfactants, particularly their impacts and changes during COVID-19 infection, through a comprehensive review of current literature. The study focuses on the function of surfactants as prognostic markers, diagnostic factors, and essential components in the management and treatment of COVID-19. FINDING In general, pulmonary surfactants serve to reduce the surface tension at the gas-liquid interface, thereby significantly contributing to the regulation of respiratory mechanics. Additionally, these surfactants play a crucial role in the innate immune system within the pulmonary microenvironment. Within the spectrum of COVID-19 infections, a compelling association is observed, characterized by elevated levels of SP-D and SP-A across a range of manifestations from mild to severe pneumonia. The sudden decline in respiratory function observed in COVID-19 patients may be attributed to the decreased synthesis of surfactants by type II alveolar cells. CONCLUSION Collectin proteins such as SP-A and SP-D show promise as biomarkers, offering potential avenues for predicting and monitoring pulmonary alveolar injury in the context of COVID-19. This clarification enhances our understanding of the molecular complexities contributing to respiratory complications in severe COVID-19 cases, providing a foundation for targeted therapeutic approaches using surfactants and refined clinical management strategies.
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Affiliation(s)
- Mohammad Navid Bastani
- Department of Medical Virology, School of MedicineAhvaz Jundishapur University of Medical SciencesAhvazIran
| | - Shahram Jalilian
- Department of Medical Virology, School of MedicineAhvaz Jundishapur University of Medical SciencesAhvazIran
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2
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Morán‐Lalangui M, Coutinho A, Prieto M, Fedorov A, Pérez‐Gil J, Loura LMS, García‐Álvarez B. Exploring protein-protein interactions and oligomerization state of pulmonary surfactant protein C (SP-C) through FRET and fluorescence self-quenching. Protein Sci 2024; 33:e4835. [PMID: 37984447 PMCID: PMC10731621 DOI: 10.1002/pro.4835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023]
Abstract
Pulmonary surfactant (PS) is a lipid-protein complex that forms films reducing surface tension at the alveolar air-liquid interface. Surfactant protein C (SP-C) plays a key role in rearranging the lipids at the PS surface layers during breathing. The N-terminal segment of SP-C, a lipopeptide of 35 amino acids, contains two palmitoylated cysteines, which affect the stability and structure of the molecule. The C-terminal region comprises a transmembrane α-helix that contains a ALLMG motif, supposedly analogous to a well-studied dimerization motif in glycophorin A. Previous studies have demonstrated the potential interaction between SP-C molecules using approaches such as Bimolecular Complementation assays or computational simulations. In this work, the oligomerization state of SP-C in membrane systems has been studied using fluorescence spectroscopy techniques. We have performed self-quenching and FRET assays to analyze dimerization of native palmitoylated SP-C and a non-palmitoylated recombinant version of SP-C (rSP-C) using fluorescently labeled versions of either protein reconstituted in different lipid systems mimicking pulmonary surfactant environments. Our results reveal that doubly palmitoylated native SP-C remains primarily monomeric. In contrast, non-palmitoylated recombinant SP-C exhibits dimerization, potentiated at high concentrations, especially in membranes with lipid phase separation. Therefore, palmitoylation could play a crucial role in stabilizing the monomeric α-helical conformation of SP-C. Depalmitoylation, high protein densities as a consequence of membrane compartmentalization, and other factors may all lead to the formation of protein dimers and higher-order oligomers, which could have functional implications under certain pathological conditions and contribute to membrane transformations associated with surfactant metabolism and alveolar homeostasis.
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Affiliation(s)
- Mishelle Morán‐Lalangui
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
| | - Ana Coutinho
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
- Department of Chemistry and BiochemistryFaculty of Sciences, University of LisbonLisbonPortugal
| | - Manuel Prieto
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
| | - Alexander Fedorov
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
| | - Jesús Pérez‐Gil
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
| | - Luís M. S. Loura
- Department of Chemistry, Coimbra Chemistry Centre, Institute of Molecular Sciences (CQC‐IMS)University of CoimbraCoimbraPortugal
- CNC Centre for Neuroscience and Cell Biology, University of CoimbraCoimbraPortugal
- Faculty of PharmacyUniversity of CoimbraCoimbraPortugal
| | - Begoña García‐Álvarez
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
- Department of Biochemistry and Molecular BiologyFaculty of Chemistry, Complutense UniversityMadridSpain
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3
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Abstract
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
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Affiliation(s)
- Fred Possmayer
- Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
- Department of Obstetrics/Gynaecology, Western University, London, Ontario N6A 3K7, Canada
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manon, Honolulu, Hawaii 96822, United States
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96826, United States
| | - Ruud A W Veldhuizen
- Department of Physiology & Pharmacology, Western University, London, Ontario N6A 5C1, Canada
- Department of Medicine, Western University, London, Ontario N6A 3K7, Canada
- Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department of Chemistry, Western University, London, Ontario N6A 5B7, Canada
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4
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Liu Q, Weng J, Li C, Feng Y, Xie M, Wang X, Chang Q, Li M, Chung KF, Adcock IM, Huang Y, Zhang H, Li F. Attenuation of PM 2.5-induced alveolar epithelial cells and lung injury through regulation of mitochondrial fission and fusion. Part Fibre Toxicol 2023; 20:28. [PMID: 37464447 DOI: 10.1186/s12989-023-00534-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 06/05/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Exposure to particulate matter (PM) with an aerodynamic diameter less than 2.5 μm (PM2.5) is a risk factor for developing pulmonary diseases and the worsening of ongoing disease. Mitochondrial fission and fusion are essential processes underlying mitochondrial homeostasis in health and disease. We examined the role of mitochondrial fission and fusion in PM2.5-induced alveolar epithelial cell damage and lung injury. Key genes in these processes include dystrophin-related protein 1 (DRP1) and optic atrophy 1 (OPA1) respectively. METHODS Alveolar epithelial (A549) cells were treated with PM2.5 (32 µg/ml) in the presence and absence of Mdivi-1 (10µM, a DRP1 inhibitor) or BGP-15 (10µM, an OPA1 activator). Results were validated using DRP1-knockdown (KD) and OPA1-overexpression (OE). Mice were injected intraperitoneally with Mdivi-1 (20 mg/kg), BGP-15 (20 mg/kg) or distilled water (control) one hour before intranasal instillation of PM2.5 (7.8 mg/kg) or distilled water for two consecutive days. RESULTS PM2.5 exposure of A549 cells caused oxidative stress, enhanced inflammation, necroptosis, mitophagy and mitochondrial dysfunction indicated by abnormal mitochondrial morphology, decreased mitochondrial membrane potential (ΔΨm), reduced mitochondrial respiration and disrupted mitochondrial fission and fusion. Regulating mitochondrial fission and fusion pharmacologically using Mdivi-1 and BGP-15 and genetically using DRP1-KD and OPA1-OE prevented PM2.5-induced celluar damage in A549 cells. Mdivi-1 and BGP-15 attenuated PM2.5-induced acute lung injury in mice. CONCLUSION Increased mitochondrial fission and decreased mitochondrial fusion may underlie PM2.5-induced alveolar epithelial cell damage in vitro and lung injury in vivo.
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Affiliation(s)
- Qi Liu
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Jiali Weng
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Chenfei Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Yi Feng
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Meiqin Xie
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Xiaohui Wang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Qing Chang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Mengnan Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Kian Fan Chung
- Airway Disease Section, National Heart and Lung Institute, Imperial College, Dovehouse Street, SW3 6LY, London, UK
| | - Ian M Adcock
- Airway Disease Section, National Heart and Lung Institute, Imperial College, Dovehouse Street, SW3 6LY, London, UK
| | - Yan Huang
- School of Pharmacy, Anhui Medical University, 230022, Hefei, Anhui, China
| | - Hai Zhang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China.
| | - Feng Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China.
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5
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Korolainen H, Lolicato F, Enkavi G, Pérez-Gil J, Kulig W, Vattulainen I. Dimerization of the pulmonary surfactant protein C in a membrane environment. PLoS One 2022; 17:e0267155. [PMID: 35476695 PMCID: PMC9045638 DOI: 10.1371/journal.pone.0267155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/01/2022] [Indexed: 11/26/2022] Open
Abstract
Surfactant protein C (SP-C) has several functions in pulmonary surfactant. These include the transfer of lipids between different membrane structures, a role in surfactant recycling and homeostasis, and involvement in modulation of the innate defense system. Despite these important functions, the structures of functional SP-C complexes have remained unclear. SP-C is known to exist as a primarily α-helical structure with an apparently unstructured N-terminal region, yet there is recent evidence that the functions of SP-C could be associated with the formation of SP-C dimers and higher oligomers. In this work, we used molecular dynamics simulations, two-dimensional umbrella sampling, and well-tempered metadynamics to study the details of SP-C dimerization. The results suggest that SP-C dimerizes in pulmonary surfactant membranes, forming dimers of different topologies. The simulations identified a dimerization motif region V21xxxVxxxGxxxM33 that is much larger than the putative A30xxxG34 motif that is commonly assumed to control the dimerization of some α-helical transmembrane domains. The results provide a stronger basis for elucidating how SP-C functions in concert with other surfactant proteins.
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Affiliation(s)
- Hanna Korolainen
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Fabio Lolicato
- Department of Physics, University of Helsinki, Helsinki, Finland
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Giray Enkavi
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Jesús Pérez-Gil
- Faculty of Biology, Department of Biochemistry and Molecular Biology, Research Institute “Hospital 12 de Octubre (imas12)”, Complutense University, Madrid, Spain
| | - Waldemar Kulig
- Department of Physics, University of Helsinki, Helsinki, Finland
- * E-mail: (WK); (IV)
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, Helsinki, Finland
- * E-mail: (WK); (IV)
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6
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Fluid Films as Models for Understanding the Impact of Inhaled Particles in Lung Surfactant Layers. COATINGS 2022. [DOI: 10.3390/coatings12020277] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Pollution is currently a public health problem associated with different cardiovascular and respiratory diseases. These are commonly originated as a result of the pollutant transport to the alveolar cavity after their inhalation. Once pollutants enter the alveolar cavity, they are deposited on the lung surfactant (LS) film, altering their mechanical performance which increases the respiratory work and can induce a premature alveolar collapse. Furthermore, the interactions of pollutants with LS can induce the formation of an LS corona decorating the pollutant surface, favoring their penetration into the bloodstream and distribution along different organs. Therefore, it is necessary to understand the most fundamental aspects of the interaction of particulate pollutants with LS to mitigate their effects, and design therapeutic strategies. However, the use of animal models is often invasive, and requires a careful examination of different bioethics aspects. This makes it necessary to design in vitro models mimicking some physico-chemical aspects with relevance for LS performance, which can be done by exploiting the tools provided by the science and technology of interfaces to shed light on the most fundamental physico-chemical bases governing the interaction between LS and particulate matter. This review provides an updated perspective of the use of fluid films of LS models for shedding light on the potential impact of particulate matter in the performance of LS film. It should be noted that even though the used model systems cannot account for some physiological aspects, it is expected that the information contained in this review can contribute on the understanding of the potential toxicological effects of air pollution.
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7
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Guagliardo R, Herman L, Penders J, Zamborlin A, De Keersmaecker H, Van de Vyver T, Verstraeten S, Merckx P, Mingeot-Leclercq MP, Echaide M, Pérez-Gil J, Stevens MM, De Smedt SC, Raemdonck K. Surfactant Protein B Promotes Cytosolic SiRNA Delivery by Adopting a Virus-like Mechanism of Action. ACS NANO 2021; 15:8095-8109. [PMID: 33724778 DOI: 10.1021/acsnano.0c04489] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
RNA therapeutics are poised to revolutionize medicine. To unlock the full potential of RNA drugs, safe and efficient (nano)formulations to deliver them inside target cells are required. Endosomal sequestration of nanocarriers represents a major bottleneck in nucleic acid delivery. Gaining more detailed information on the intracellular behavior of RNA nanocarriers is crucial to rationally develop delivery systems with improved therapeutic efficiency. Surfactant protein B (SP-B) is a key component of pulmonary surfactant (PS), essential for mammalian breathing. In contrast to the general belief that PS should be regarded as a barrier for inhaled nanomedicines, we recently discovered the ability of SP-B to promote gene silencing by siRNA-loaded and lipid-coated nanogels. However, the mechanisms governing this process are poorly understood. The major objective of this work was to obtain mechanistic insights into the SP-B-mediated cellular delivery of siRNA. To this end, we combined siRNA knockdown experiments, confocal microscopy, and focused ion beam scanning electron microscopy imaging in an in vitro non-small-cell lung carcinoma model with lipid mixing assays on vesicles that mimic the composition of (intra)cellular membranes. Our work highlights a strong correlation between SP-B-mediated fusion with anionic endosomal membranes and cytosolic siRNA delivery, a mode of action resembling that of certain viruses and virus-derived cell-penetrating peptides. Building on these gained insights, we optimized the SP-B proteolipid composition, which dramatically improved delivery efficiency. Altogether, our work provides a mechanistic understanding of SP-B-induced perturbation of intracellular membranes, offering opportunities to fuel the rational design of SP-B-inspired RNA nanoformulations for inhalation therapy.
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Affiliation(s)
- Roberta Guagliardo
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Lore Herman
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Jelle Penders
- Department of Materials, Department of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Agata Zamborlin
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Herlinde De Keersmaecker
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
- Centre for Advanced Light Microscopy, Ghent University, 9000 Ghent, Belgium
| | - Thijs Van de Vyver
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Sandrine Verstraeten
- Université Catholique de Louvain, Louvain Drug Research Institute, Pharmacologie Cellulaire et Moléculaire, Avenue E. Mounier 73, UCL B1.73.05, 1200 Brussels, Belgium
| | - Pieterjan Merckx
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Marie-Paule Mingeot-Leclercq
- Université Catholique de Louvain, Louvain Drug Research Institute, Pharmacologie Cellulaire et Moléculaire, Avenue E. Mounier 73, UCL B1.73.05, 1200 Brussels, Belgium
| | - Mercedes Echaide
- Departamento de Bioquímica y Biología Molecular, Facultad de Biologia, and Research Institute Hospital 12 de Octubre, Universidad Complutense, José Antonio Novais 12, 28040 Madrid, Spain
| | - Jesús Pérez-Gil
- Departamento de Bioquímica y Biología Molecular, Facultad de Biologia, and Research Institute Hospital 12 de Octubre, Universidad Complutense, José Antonio Novais 12, 28040 Madrid, Spain
| | - Molly M Stevens
- Department of Materials, Department of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Stefaan C De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
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Kiener M, Roldan N, Machahua C, Sengupta A, Geiser T, Guenat OT, Funke-Chambour M, Hobi N, Kruithof-de Julio M. Human-Based Advanced in vitro Approaches to Investigate Lung Fibrosis and Pulmonary Effects of COVID-19. Front Med (Lausanne) 2021; 8:644678. [PMID: 34026781 PMCID: PMC8139419 DOI: 10.3389/fmed.2021.644678] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/01/2021] [Indexed: 12/15/2022] Open
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has caused considerable socio-economic burden, which fueled the development of treatment strategies and vaccines at an unprecedented speed. However, our knowledge on disease recovery is sparse and concerns about long-term pulmonary impairments are increasing. Causing a broad spectrum of symptoms, COVID-19 can manifest as acute respiratory distress syndrome (ARDS) in the most severely affected patients. Notably, pulmonary infection with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), the causing agent of COVID-19, induces diffuse alveolar damage (DAD) followed by fibrotic remodeling and persistent reduced oxygenation in some patients. It is currently not known whether tissue scaring fully resolves or progresses to interstitial pulmonary fibrosis. The most aggressive form of pulmonary fibrosis is idiopathic pulmonary fibrosis (IPF). IPF is a fatal disease that progressively destroys alveolar architecture by uncontrolled fibroblast proliferation and the deposition of collagen and extracellular matrix (ECM) proteins. It is assumed that micro-injuries to the alveolar epithelium may be induced by inhalation of micro-particles, pathophysiological mechanical stress or viral infections, which can result in abnormal wound healing response. However, the exact underlying causes and molecular mechanisms of lung fibrosis are poorly understood due to the limited availability of clinically relevant models. Recently, the emergence of SARS-CoV-2 with the urgent need to investigate its pathogenesis and address drug options, has led to the broad application of in vivo and in vitro models to study lung diseases. In particular, advanced in vitro models including precision-cut lung slices (PCLS), lung organoids, 3D in vitro tissues and lung-on-chip (LOC) models have been successfully employed for drug screens. In order to gain a deeper understanding of SARS-CoV-2 infection and ultimately alveolar tissue regeneration, it will be crucial to optimize the available models for SARS-CoV-2 infection in multicellular systems that recapitulate tissue regeneration and fibrotic remodeling. Current evidence for SARS-CoV-2 mediated pulmonary fibrosis and a selection of classical and novel lung models will be discussed in this review.
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Affiliation(s)
- Mirjam Kiener
- Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research DBMR, Urology Research Laboratory, University of Bern, Bern, Switzerland
- Alveolix AG, Swiss Organs-on-Chip Innovation, Bern, Switzerland
| | - Nuria Roldan
- Alveolix AG, Swiss Organs-on-Chip Innovation, Bern, Switzerland
| | - Carlos Machahua
- Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research DBMR, Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Arunima Sengupta
- Organs-on-Chip Technologies, ARTORG Center for Biomedical Engineering, University of Bern, Bern, Switzerland
| | - Thomas Geiser
- Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research DBMR, Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Olivier Thierry Guenat
- Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Organs-on-Chip Technologies, ARTORG Center for Biomedical Engineering, University of Bern, Bern, Switzerland
- Department of General Thoracic Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Manuela Funke-Chambour
- Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research DBMR, Department of Pulmonary Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Nina Hobi
- Alveolix AG, Swiss Organs-on-Chip Innovation, Bern, Switzerland
| | - Marianna Kruithof-de Julio
- Department for BioMedical Research DBMR, Urology Research Laboratory, University of Bern, Bern, Switzerland
- Alveolix AG, Swiss Organs-on-Chip Innovation, Bern, Switzerland
- Organoid Core, Department for BioMedical Research, University of Bern, Bern, Switzerland
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9
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Structural hallmarks of lung surfactant: Lipid-protein interactions, membrane structure and future challenges. Arch Biochem Biophys 2021; 703:108850. [PMID: 33753033 DOI: 10.1016/j.abb.2021.108850] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/20/2021] [Accepted: 03/16/2021] [Indexed: 11/23/2022]
Abstract
Lung surfactant (LS) is an outstanding example of how a highly regulated and dynamic membrane-based system has evolved to sustain a wealth of structural reorganizations in order to accomplish its biophysical function, as it coats and stabilizes the respiratory air-liquid interface in the mammalian lung. The present review dissects the complexity of the structure-function relationships in LS through an updated description of the lipid-protein interactions and the membrane structures that sustain its synthesis, secretion, interfacial performance and recycling. We also revise the current models and the biophysical techniques employed to study the membranous architecture of LS. It is important to consider that the structure and functional properties of LS are often studied in bulk or under static conditions, in spite that surfactant function is strongly connected with a highly dynamic behaviour, sustained by very polymorphic structures and lipid-lipid, lipid-protein and protein-protein interactions that reorganize in precise spatio-temporal coordinates. We have tried to underline the evidences available of the existence of such structural dynamism in LS. A last important aspect is that the synthesis and assembly of LS is a strongly regulated intracellular process to ensure the establishment of the proper interactions driving LS surface activity, while protecting the integrity of other cell membranes. The use of simplified lipid models or partial natural materials purified from animal tissues could be too simplistic to understand the true molecular mechanisms defining surfactant function in vivo. In this line, we will bring into the attention of the reader the methodological challenges and the questions still open to understand the structure-function relationships of LS at its full biological relevance.
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10
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Wang K, Wang J, Zhu C, Yang L, Ren Y, Ruan J, Fan G, Hu J, Xu W, Bi X, Zhu Y, Song Y, Chen H, Ma T, Zhao R, Jiang H, Zhang B, Feng C, Yuan Y, Gan X, Li Y, Zeng H, Liu Q, Zhang Y, Shao F, Hao S, Zhang H, Xu X, Liu X, Wang D, Zhu M, Zhang G, Zhao W, Qiu Q, He S, Wang W. African lungfish genome sheds light on the vertebrate water-to-land transition. Cell 2021; 184:1362-1376.e18. [PMID: 33545087 DOI: 10.1016/j.cell.2021.01.047] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/09/2020] [Accepted: 01/27/2021] [Indexed: 12/26/2022]
Abstract
Lungfishes are the closest extant relatives of tetrapods and preserve ancestral traits linked with the water-to-land transition. However, their huge genome sizes have hindered understanding of this key transition in evolution. Here, we report a 40-Gb chromosome-level assembly of the African lungfish (Protopterus annectens) genome, which is the largest genome assembly ever reported and has a contig and chromosome N50 of 1.60 Mb and 2.81 Gb, respectively. The large size of the lungfish genome is due mainly to retrotransposons. Genes with ultra-long length show similar expression levels to other genes, indicating that lungfishes have evolved high transcription efficacy to keep gene expression balanced. Together with transcriptome and experimental data, we identified potential genes and regulatory elements related to such terrestrial adaptation traits as pulmonary surfactant, anxiolytic ability, pentadactyl limbs, and pharyngeal remodeling. Our results provide insights and key resources for understanding the evolutionary pathway leading from fishes to humans.
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Affiliation(s)
- Kun Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Jun Wang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, China
| | - Chenglong Zhu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Liandong Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yandong Ren
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Jue Ruan
- Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Guangyi Fan
- BGI-Qingdao, Qingdao 266555, China; BGI-Shenzhen, Shenzhen 518083, China
| | - Jiang Hu
- Grandomics Biosciences, Beijing 102200, China
| | - Wenjie Xu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Xupeng Bi
- BGI-Shenzhen, Shenzhen 518083, China
| | - Youan Zhu
- Institute of Vertebrate Paleontology and Paleoanthropology, China Academy of Sciences, Beijing 100044, China
| | - Yue Song
- BGI-Qingdao, Qingdao 266555, China
| | - Huatao Chen
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China
| | - Tiantian Ma
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China
| | - Ruoping Zhao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Haifeng Jiang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Bin Zhang
- Beijing Institute of Genomics, Chinese Academy of Sciences, and China National Center for Bioinformation, Beijing 100101, China
| | - Chenguang Feng
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yuan Yuan
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Xiaoni Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yongxin Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Honghui Zeng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Qun Liu
- BGI-Qingdao, Qingdao 266555, China
| | | | - Feng Shao
- Key Laboratory of Freshwater Fish Reproduction and Development, School of Life Sciences, Southwest University, Chongqing 400715, China
| | | | - He Zhang
- BGI-Qingdao, Qingdao 266555, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Xin Liu
- BGI-Qingdao, Qingdao 266555, China
| | - Depeng Wang
- Grandomics Biosciences, Beijing 102200, China
| | - Min Zhu
- Institute of Vertebrate Paleontology and Paleoanthropology, China Academy of Sciences, Beijing 100044, China
| | - Guojie Zhang
- BGI-Shenzhen, Shenzhen 518083, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China; Villum Center for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Wenming Zhao
- Beijing Institute of Genomics, Chinese Academy of Sciences, and China National Center for Bioinformation, Beijing 100101, China.
| | - Qiang Qiu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Shunping He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China; Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China.
| | - Wen Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China.
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11
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Barriga A, Morán-Lalangui M, Castillo-Sánchez JC, Mingarro I, Pérez-Gil J, García-Álvarez B. Role of pulmonary surfactant protein Sp-C dimerization on membrane fragmentation: An emergent mechanism involved in lung defense and homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183572. [PMID: 33548215 DOI: 10.1016/j.bbamem.2021.183572] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/18/2021] [Accepted: 01/29/2021] [Indexed: 01/22/2023]
Abstract
Surfactant protein C (SP-C) is a protein present in the pulmonary surfactant system that is involved in the biophysical properties of this lipoprotein complex, but it also has a role in lung defense and homeostasis. In this article, we propose that the link between both functions could rely on the ability of SP-C to induce fragmentation of phospholipid membranes and generate small vesicles that serve as support to present different ligands to cells in the lungs. Our results using bimolecular fluorescence complementation and tunable resistive pulse sensing setups suggest that SP-C oligomerization could be the triggering event that causes membrane budding and nanovesiculation. As shown by fluorescence microscopy and flow cytometry, these vesicles are differentially assimilated by alveolar macrophages and alveolar type II cells, indicating distinct roles of these alveoli-resident cells in the processing of the SP-C- induced vesicles and their cargo. These results depict a more accurate picture of the mechanisms of this protein, which could be relevant for the comprehension of pulmonary pathologies and the development of new therapeutic approaches.
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Affiliation(s)
- Alejandro Barriga
- Department of Biochemistry and Molecular Biology, Faculty of Biology and Faculty of Chemistry, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Madrid, Spain
| | - Michelle Morán-Lalangui
- Department of Biochemistry and Molecular Biology, Faculty of Biology and Faculty of Chemistry, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Madrid, Spain
| | - José Carlos Castillo-Sánchez
- Department of Biochemistry and Molecular Biology, Faculty of Biology and Faculty of Chemistry, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Madrid, Spain
| | - Ismael Mingarro
- Department of Biochemistry and Molecular Biology, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Valencia, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry and Molecular Biology, Faculty of Biology and Faculty of Chemistry, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Madrid, Spain
| | - Begoña García-Álvarez
- Department of Biochemistry and Molecular Biology, Faculty of Biology and Faculty of Chemistry, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Madrid, Spain.
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12
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Martínez-Calle M, Parra-Ortiz E, Cruz A, Olmeda B, Pérez-Gil J. Towards the Molecular Mechanism of Pulmonary Surfactant Protein SP-B: At the Crossroad of Membrane Permeability and Interfacial Lipid Transfer. J Mol Biol 2020; 433:166749. [PMID: 33309854 DOI: 10.1016/j.jmb.2020.166749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/14/2020] [Accepted: 12/03/2020] [Indexed: 11/17/2022]
Abstract
Pulmonary surfactant is a lipid-protein complex that coats the alveolar air-liquid interface, enabling the proper functioning of lung mechanics. The hydrophobic surfactant protein SP-B, in particular, plays an indispensable role in promoting the rapid adsorption of phospholipids into the interface. For this, formation of SP-B ring-shaped assemblies seems to be important, as oligomerization could be required for the ability of the protein to generate membrane contacts and to mediate lipid transfer among surfactant structures. SP-B, together with the other hydrophobic surfactant protein SP-C, also promotes permeability of surfactant membranes to polar molecules although the molecular mechanisms underlying this property, as well as its relevance for the surface activity of the protein, remain undefined. In this work, the contribution of SP-B and SP-C to surfactant membrane permeability has been further investigated, by evaluation of the ability of differently-sized fluorescent polar probes to permeate through giant vesicles with different lipid/protein composition. Our results are consistent with the generation by SP-B of pores with defined size in surfactant membranes. Furthermore, incubation of surfactant with an anti-SP-B antibody not only blocked membrane permeability but also affected lipid transfer into the air-water interface, as observed in a captive bubble surfactometer device. Our findings include the identification of SP-C and anionic phospholipids as modulators required for maintaining native-like permeability features in pulmonary surfactant membranes. Proper permeability through membrane assemblies could be crucial to complement the overall role of surfactant in maintaining alveolar equilibrium, beyond its biophysical function in stabilizing the respiratory air-liquid interface.
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Affiliation(s)
- Marta Martínez-Calle
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Elisa Parra-Ortiz
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain
| | - Antonio Cruz
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Barbara Olmeda
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain.
| | - Jesús Pérez-Gil
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
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13
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Oseliero Filho PL, Gerbelli BB, Fornasier F, Chaves Filho AB, Yoshinaga MY, Miyamoto S, Mortara L, Lacerda CD, Cuccovia IM, Pimentel AS, Oliveira CLP. Structure and Thermotropic Behavior of Bovine- and Porcine-Derived Exogenous Lung Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:14514-14529. [PMID: 33210931 DOI: 10.1021/acs.langmuir.0c02224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Two commercial exogenous pulmonary surfactants, Curosurf and Survanta, are investigated. Their thermotropic behavior and associated structural changes for the samples in bulk are characterized and described. For Survanta, the obtained results of differential scanning calorimetry showed a thermogram with three peaks on heating and only a single peak on cooling. Curosurf on the other hand, presents calorimetric thermograms with only one peak in both the heating and cooling scans. This distinct thermotropic behavior between the two pulmonary surfactants, a consequence of their particular compositions, is associated with structural changes that were evaluated by simultaneous small- and wide-angle X-ray scattering experiments with in situ temperature variation. Interestingly, for temperatures below ∼35 °C for Curosurf and ∼53 °C for Survanta, the scattering data indicated the coexistence of two lamellar phases with different carbon chain organizations. For temperatures above these limits, the coexistence of phases disappears, giving rise to a fluid phase in both pulmonary surfactants, with multilamelar vesicles for Curosurf and unilamellar vesicles for Survanta. This process is quasi-reversible under cooling, and advanced data analysis for the scattering data indicated differences in the structural and elastic properties of the pulmonary surfactants. The detailed and systematic investigation shown in this work expands on the knowledge of the structure and thermodynamic behavior of Curosurf and Survanta, being relevant from both physiological and biophysical perspectives and also providing a basis for further studies on other types of pulmonary surfactants.
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Affiliation(s)
| | - Barbara Bianca Gerbelli
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP 09210-580, Brazil
| | - Franccesca Fornasier
- Departamento de Química, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ 22453-900, Brazil
| | - Adriano B Chaves Filho
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Marcos Yukio Yoshinaga
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Sayuri Miyamoto
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Laura Mortara
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Caroline Dutra Lacerda
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Iolanda Midea Cuccovia
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - André Silva Pimentel
- Departamento de Química, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ 22453-900, Brazil
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14
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Da Silva E, Autilio C, Hougaard KS, Baun A, Cruz A, Perez-Gil J, Sørli JB. Molecular and biophysical basis for the disruption of lung surfactant function by chemicals. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183499. [PMID: 33137304 DOI: 10.1016/j.bbamem.2020.183499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 10/19/2020] [Indexed: 02/06/2023]
Abstract
With the intention to move away from animal testing for the toxicological evaluation of chemicals comes the need to develop new approach methodologies which are mechanism-anchored and target relevant key events leading to an adverse outcome. To date, no validated alternative methods are available for studying the acute inhalation toxicity potential of airborne chemicals but the constrained drop surfactometer measuring the surface tension of a drop of lung surfactant presents as a promising candidate. Indeed, the correlation of the increase in minimum surface tension of lung surfactant in vitro with changes in the breathing patterns of mice after inhalation of test compounds has been shown in multiple studies. However, the causal factors leading to lung surfactant inactivation remain speculative. This paper combines molecular and biophysical methods (constrained drop and captive bubble surfactometers, Langmuir-Blodgett balance, epifluorescence microscopy, cryogenic transmission electron microscopy, and differential scanning calorimetry) applied to purified porcine lung surfactant and dipalmitoylphosphatidylcholine interfacial films to gain insights into the disruption of lung surfactant function by three chemicals known to show acute inhalation toxicity (trimethoxyoctylsilane, methyl 3-oxo-2-pentylcyclopentaneacetate, and diisopentyl ether). The results of this study suggest that the test chemicals intercalate between the phospholipids at the air-liquid interface, reduce the stability of the films, and decrease the cohesivity of interface-associated multilayered structures thereby perturbing the lung surfactant surface activity. These findings contribute to a better understanding of chemically-induced lung surfactant function disruption.
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Affiliation(s)
- Emilie Da Silva
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark; National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Chiara Autilio
- Department of Biochemistry and Molecular Biology, Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | | | - Anders Baun
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Antonio Cruz
- Department of Biochemistry and Molecular Biology, Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Jesus Perez-Gil
- Department of Biochemistry and Molecular Biology, Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
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15
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Autilio C, Echaide M, Shankar-Aguilera S, Bragado R, Amidani D, Salomone F, Pérez-Gil J, De Luca D. Surfactant Injury in the Early Phase of Severe Meconium Aspiration Syndrome. Am J Respir Cell Mol Biol 2020; 63:327-337. [PMID: 32348683 DOI: 10.1165/rcmb.2019-0413oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
No in vivo data are available regarding the effect of meconium on human surfactant in the early stages of severe meconium aspiration syndrome (MAS). In the present study, we sought to characterize the changes in surfactant composition, function, and structure during the early phase of meconium injury. We designed a translational prospective cohort study of nonbronchoscopic BAL of neonates with severe MAS (n = 14) or no lung disease (n = 18). Surfactant lipids were analyzed by liquid chromatography-high-resolution mass spectrometry. Secretory phospholipase A2 subtypes IB, V, and X and SP-A (surfactant protein A) were assayed by ELISA. SP-B and SP-C were analyzed by Western blotting under both nonreducing and reducing conditions. Surfactant function was assessed by adsorption test and captive bubble surfactometry, and lung aeration was evaluated by semiquantitative lung ultrasound. Surfactant nanostructure was studied using cryo-EM and atomic force microscopy. Several changes in phospholipid subclasses were detected during MAS. Lysophosphatidylcholine species released by phospholipase A2 hydrolysis were increased. SP-B and SP-C were significantly increased together with some shorter immature forms of SP-B. Surfactant function was impaired and correlated with poor lung aeration. Surfactant nanostructure was significantly damaged in terms of vesicle size, tridimensional complexity, and compactness. Various alterations of surfactant phospholipids and proteins were detected in the early phase of severe meconium aspiration and were due to hydrolysis and inflammation and a defensive response. This impairs both surfactant structure and function, finally resulting in reduced lung aeration. These findings support the development of new surfactant protection and antiinflammatory strategies for severe MAS.
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Affiliation(s)
- Chiara Autilio
- Department of Biochemistry and Molecular Biology and Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Mercedes Echaide
- Department of Biochemistry and Molecular Biology and Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Shivani Shankar-Aguilera
- Division of Pediatrics and Neonatal Critical Care, A. Béclère Medical Center, Paris Saclay University Hospitals, APHP, Paris, France
| | - Rafael Bragado
- Research Institute "Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS FJD)", Madrid, Spain
| | - Davide Amidani
- Pharmacology and Toxicology Department Preclinical R&D, Chiesi Farmaceutici, Parma, Italy; and
| | - Fabrizio Salomone
- Pharmacology and Toxicology Department Preclinical R&D, Chiesi Farmaceutici, Parma, Italy; and
| | - Jesús Pérez-Gil
- Department of Biochemistry and Molecular Biology and Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Daniele De Luca
- Division of Pediatrics and Neonatal Critical Care, A. Béclère Medical Center, Paris Saclay University Hospitals, APHP, Paris, France.,Physiopathology and Therapeutic Innovation Unit, INSERM U999, Paris-Saclay University, Paris, France
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16
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Lopez-Rodriguez E, Ochs M. Reply to: Comments on “Air Space Distension Precedes Spontaneous Fibrotic Remodeling and Impaired Cholesterol Metabolism in the Absence of Surfactant Protein C”. Am J Respir Cell Mol Biol 2020; 63:399-402. [DOI: 10.1165/rcmb.2020-0158le] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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17
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Lipid-Protein and Protein-Protein Interactions in the Pulmonary Surfactant System and Their Role in Lung Homeostasis. Int J Mol Sci 2020; 21:ijms21103708. [PMID: 32466119 PMCID: PMC7279303 DOI: 10.3390/ijms21103708] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Pulmonary surfactant is a lipid/protein complex synthesized by the alveolar epithelium and secreted into the airspaces, where it coats and protects the large respiratory air–liquid interface. Surfactant, assembled as a complex network of membranous structures, integrates elements in charge of reducing surface tension to a minimum along the breathing cycle, thus maintaining a large surface open to gas exchange and also protecting the lung and the body from the entrance of a myriad of potentially pathogenic entities. Different molecules in the surfactant establish a multivalent crosstalk with the epithelium, the immune system and the lung microbiota, constituting a crucial platform to sustain homeostasis, under health and disease. This review summarizes some of the most important molecules and interactions within lung surfactant and how multiple lipid–protein and protein–protein interactions contribute to the proper maintenance of an operative respiratory surface.
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18
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Sehlmeyer K, Ruwisch J, Roldan N, Lopez-Rodriguez E. Alveolar Dynamics and Beyond - The Importance of Surfactant Protein C and Cholesterol in Lung Homeostasis and Fibrosis. Front Physiol 2020; 11:386. [PMID: 32431623 PMCID: PMC7213507 DOI: 10.3389/fphys.2020.00386] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
Surfactant protein C (SP-C) is an important player in enhancing the interfacial adsorption of lung surfactant lipid films to the alveolar air-liquid interface. Doing so, surface tension drops down enough to stabilize alveoli and the lung, reducing the work of breathing. In addition, it has been shown that SP-C counteracts the deleterious effect of high amounts of cholesterol in the surfactant lipid films. On its side, cholesterol is a well-known modulator of the biophysical properties of biological membranes and it has been proven that it activates the inflammasome pathways in the lung. Even though the molecular mechanism is not known, there are evidences suggesting that these two molecules may interplay with each other in order to keep the proper function of the lung. This review focuses in the role of SP-C and cholesterol in the development of lung fibrosis and the potential pathways in which impairment of both molecules leads to aberrant lung repair, and therefore impaired alveolar dynamics. From molecular to cellular mechanisms to evidences in animal models and human diseases. The evidences revised here highlight a potential SP-C/cholesterol axis as target for the treatment of lung fibrosis.
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Affiliation(s)
- Kirsten Sehlmeyer
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Centre for Lung Research, Hanover, Germany
| | - Jannik Ruwisch
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Centre for Lung Research, Hanover, Germany
| | - Nuria Roldan
- Alveolix AG and ARTORG Center, University of Bern, Bern, Switzerland
| | - Elena Lopez-Rodriguez
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Centre for Lung Research, Hanover, Germany
- Institute of Functional Anatomy, Charité – Universitätsmedizin Berlin, Berlin, Germany
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19
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Liekkinen J, Enkavi G, Javanainen M, Olmeda B, Pérez-Gil J, Vattulainen I. Pulmonary Surfactant Lipid Reorganization Induced by the Adsorption of the Oligomeric Surfactant Protein B Complex. J Mol Biol 2020; 432:3251-3268. [DOI: 10.1016/j.jmb.2020.02.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/22/2020] [Accepted: 02/24/2020] [Indexed: 12/11/2022]
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20
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Martínez-Calle M, Alonso A, Pérez-Gil J, Olmeda B. Native supramolecular protein complexes in pulmonary surfactant: Evidences for SP-A/SP-B interactions. J Proteomics 2019; 207:103466. [DOI: 10.1016/j.jprot.2019.103466] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/08/2019] [Accepted: 07/22/2019] [Indexed: 12/21/2022]
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21
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Guagliardo R, Pérez-Gil J, De Smedt S, Raemdonck K. Pulmonary surfactant and drug delivery: Focusing on the role of surfactant proteins. J Control Release 2018; 291:116-126. [PMID: 30321577 DOI: 10.1016/j.jconrel.2018.10.012] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/06/2018] [Accepted: 10/08/2018] [Indexed: 11/30/2022]
Abstract
Pulmonary surfactant (PS) has been extensively studied because of its primary role in mammalian breathing. The deposition of this surface-active material at the alveolar air-water interface is essential to lower surface tension, thus avoiding alveolar collapse during expiration. In addition, PS is involved in host defense, facilitating the clearance of potentially harmful particulates. PS has a unique composition, including 92% of lipids and 8% of surfactant proteins (SPs) by mass. Although they constitute the minor fraction, SPs to a large extent orchestrate PS-related functions. PS contains four surfactant proteins (SPs) that can be structurally and functionally divided in two groups, i.e. the large hydrophilic SP-A and SP-D and the smaller hydrophobic SP-B and SP-C. The former belong to the family of collectins and are involved in opsonization processes, thus promoting uptake of pathogens and (nano)particles by phagocytic cell types. The latter SPs regulate interfacial surfactant adsorption dynamics, facilitating (phospho)lipid transfer and membrane fusion processes. In the context of pulmonary drug delivery, the exploitation of PS as a carrier to promote drug spreading along the alveolar interface is gaining interest. In addition, recent studies investigated the interaction of PS with drug-loaded nanoparticles (nanomedicines) following pulmonary administration, which strongly influences their biological fate, drug delivery efficiency and toxicological profile. Interestingly, the specific biophysical mode-of-action of the four SPs affect the drug delivery process of nanomedicines both on the extra-and intracellular level, modulating pulmonary distribution, cell targeting and intracellular delivery. This knowledge can be harnessed to exploit SPs for the design of unique and bio-inspired drug delivery strategies.
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Affiliation(s)
- Roberta Guagliardo
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
| | - Jesús Pérez-Gil
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Research Institute Hospital 12 Octubre, Universidad Complutense, José Antonio Novais 2, 28040 Madrid, Spain.
| | - Stefaan De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
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22
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Cabré EJ, Martínez-Calle M, Prieto M, Fedorov A, Olmeda B, Loura LMS, Pérez-Gil J. Homo- and hetero-oligomerization of hydrophobic pulmonary surfactant proteins SP-B and SP-C in surfactant phospholipid membranes. J Biol Chem 2018; 293:9399-9411. [PMID: 29700110 DOI: 10.1074/jbc.ra117.000222] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 03/28/2018] [Indexed: 11/06/2022] Open
Abstract
Pulmonary surfactant is a lipid/protein mixture that reduces surface tension at the respiratory air-water interface in lungs. Among its nonlipidic components are pulmonary surfactant-associated proteins B and C (SP-B and SP-C, respectively). These highly hydrophobic proteins are required for normal pulmonary surfactant function, and whereas past literature works have suggested possible SP-B/SP-C interactions and a reciprocal modulation effect, no direct evidence has been yet identified. In this work, we report an extensive fluorescence spectroscopy study of both intramolecular and intermolecular SP-B and SP-C interactions, using a combination of quenching and FRET steady-state and time-resolved methodologies. These proteins are compartmentalized in full surfactant membranes but not in pure 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) vesicles, in accordance with their previously described preference for liquid disordered phases. From the observed static self-quenching and homo-FRET of BODIPY-FL labeled SP-B, we conclude that this protein forms homoaggregates at low concentration (lipid:protein ratio, 1:1000). Increases in polarization of BODIPY-FL SP-B and steady-state intensity of WT SP-B were observed upon incorporation of under-stoichiometric amounts of WT SP-C. Conversely, Marina Blue-labeled SP-C is quenched by over-stoichiometric amounts of WT SP-B, whereas under-stoichiometric concentrations of the latter actually increase SP-C emission. Time-resolved hetero-FRET from Marina Blue SP-C to BODIPY-FL SP-B confirm distinct protein aggregation behaviors with varying SP-B concentration. Based on these multiple observations, we propose a model for SP-B/SP-C interactions, where SP-C might induce conformational changes on SP-B complexes, affecting its aggregation state. The conclusions inferred from the present work shed light on the synergic functionality of both proteins in the pulmonary surfactant system.
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Affiliation(s)
- Elisa J Cabré
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain
| | - Marta Martínez-Calle
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain.,the Hospital 12 Octubre Research Institute, Madrid 28041, Spain
| | - Manuel Prieto
- the CQFM-IN and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Alexander Fedorov
- the CQFM-IN and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Bárbara Olmeda
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain.,the Hospital 12 Octubre Research Institute, Madrid 28041, Spain
| | - Luís M S Loura
- the Faculty of Pharmacy, University of Coimbra, Coimbra 3000-548, Portugal, and .,the Centro de Química de Coimbra, University of Coimbra, Coimbra 3004-535, Portugal
| | - Jesús Pérez-Gil
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain, .,the Hospital 12 Octubre Research Institute, Madrid 28041, Spain
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23
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Roldan N, Pérez-Gil J, Morrow MR, García-Álvarez B. Divide & Conquer: Surfactant Protein SP-C and Cholesterol Modulate Phase Segregation in Lung Surfactant. Biophys J 2017; 113:847-859. [PMID: 28834721 PMCID: PMC5567427 DOI: 10.1016/j.bpj.2017.06.059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 05/15/2017] [Accepted: 06/26/2017] [Indexed: 02/04/2023] Open
Abstract
Lung surfactant (LS) is an essential system supporting the respiratory function. Cholesterol can be deleterious for LS function, a condition that is reversed by the presence of the lipopeptide SP-C. In this work, the structure of LS-mimicking membranes has been analyzed under the combined effect of SP-C and cholesterol by deuterium NMR and phosphorus NMR and by electron spin resonance. Our results show that SP-C induces phase segregation at 37°C, resulting in an ordered phase with spectral features resembling an interdigitated state enriched in dipalmitoylphosphatidylcholine, a liquid-crystalline bilayer phase, and an extremely mobile phase consistent with small vesicles or micelles. In the presence of cholesterol, POPC and POPG motion seem to be more hindered by SP-C than dipalmitoylphosphatidylcholine. The use of deuterated cholesterol did not show signs of specific interactions that could be attributed to SP-C or to the other hydrophobic surfactant protein SP-B. Palmitoylation of SP-C had an indirect effect on the extent of protein-lipid perturbations by stabilizing SP-C structure, and seemed to be important to maximize differences among the lipids participating in each phase. These results shed some light on how SP-C-induced lipid perturbations can alter membrane structure to sustain LS functionality at the air-liquid interface.
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Affiliation(s)
- Nuria Roldan
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Michael R Morrow
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Begoña García-Álvarez
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain.
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24
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Hidalgo A, Cruz A, Pérez-Gil J. Pulmonary surfactant and nanocarriers: Toxicity versus combined nanomedical applications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1740-1748. [PMID: 28450046 DOI: 10.1016/j.bbamem.2017.04.019] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 01/05/2023]
Abstract
Pulmonary surfactant is a membrane-based lipid-protein system essential for the process of breathing, which coats and stabilizes the whole respiratory surface and possesses exceptional biophysical properties. It constitutes the first barrier against the entry of pathogens and harmful particles in the alveolar region, extended through the lungs, but on the other hand, it can offer novel possibilities as a shuttle for the delivery of drugs and nanocarriers. The advances in nanotechnology are opening the doors to new diagnostic and therapeutic avenues, which are not accessible by means of the current approaches. In this context, the pulmonary route is called to become a powerful way of entry for innovative treatments based on nanotechnology. In this review, the anatomy of the respiratory system and its properties for drug entry are first revisited, as well as some current strategies that use the respiratory route for both local and peripheral action. Then, a brief overview is presented on what pulmonary surfactant is, how it works and why it could be used as a drug delivery vehicle. Finally, the review is closed with a description of the development of nanocarriers in the lung context and their interaction with endogenous and clinical pulmonary surfactants. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Alberto Hidalgo
- Department of Biochemistry, Fac. of Biology, and Research Institut "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Antonio Cruz
- Department of Biochemistry, Fac. of Biology, and Research Institut "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry, Fac. of Biology, and Research Institut "Hospital 12 de Octubre", Complutense University, Madrid, Spain.
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25
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Olmeda B, Martínez-Calle M, Pérez-Gil J. Pulmonary surfactant metabolism in the alveolar airspace: Biogenesis, extracellular conversions, recycling. Ann Anat 2016; 209:78-92. [PMID: 27773772 DOI: 10.1016/j.aanat.2016.09.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/22/2016] [Accepted: 09/25/2016] [Indexed: 01/03/2023]
Abstract
Pulmonary surfactant is a lipid-protein complex that lines and stabilizes the respiratory interface in the alveoli, allowing for gas exchange during the breathing cycle. At the same time, surfactant constitutes the first line of lung defense against pathogens. This review presents an updated view on the processes involved in biogenesis and intracellular processing of newly synthesized and recycled surfactant components, as well as on the extracellular surfactant transformations before and after the formation of the surface active film at the air-water interface. Special attention is paid to the crucial regulation of surfactant homeostasis, because its disruption is associated with several lung pathologies.
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Affiliation(s)
- Bárbara Olmeda
- Department of Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, 28040 Madrid, Spain
| | - Marta Martínez-Calle
- Department of Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, 28040 Madrid, Spain
| | - Jesus Pérez-Gil
- Department of Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, 28040 Madrid, Spain.
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