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The Role of Pulmonary Surfactant Phospholipids in Fibrotic Lung Diseases. Int J Mol Sci 2022; 24:ijms24010326. [PMID: 36613771 PMCID: PMC9820286 DOI: 10.3390/ijms24010326] [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: 11/10/2022] [Revised: 12/13/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Diffuse parenchymal lung diseases (DPLD) or Interstitial lung diseases (ILD) are a heterogeneous group of lung conditions with common characteristics that can progress to fibrosis. Within this group of pneumonias, idiopathic pulmonary fibrosis (IPF) is considered the most common. This disease has no known cause, is devastating and has no cure. Chronic lesion of alveolar type II (ATII) cells represents a key mechanism for the development of IPF. ATII cells are specialized in the biosynthesis and secretion of pulmonary surfactant (PS), a lipid-protein complex that reduces surface tension and minimizes breathing effort. Some differences in PS composition have been reported between patients with idiopathic pulmonary disease and healthy individuals, especially regarding some specific proteins in the PS; however, few reports have been conducted on the lipid components. This review focuses on the mechanisms by which phospholipids (PLs) could be involved in the development of the fibroproliferative response.
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A recipe for a good clinical pulmonary surfactant. Biomed J 2022; 45:615-628. [PMID: 35272060 PMCID: PMC9486245 DOI: 10.1016/j.bj.2022.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 12/11/2022] Open
Abstract
The lives of thousands premature babies have been saved along the last thirty years thanks to the establishment and consolidation of pulmonary surfactant replacement therapies (SRT). It took some time to close the gap between the identification of the biophysical and molecular causes of the high mortality associated with respiratory distress syndrome in very premature babies and the development of a proper therapy. Closing the gap required the elucidation of some key questions defining the structure–function relationships in surfactant as well as the particular role of the different molecular components assembled into the surfactant system. On the other hand, the application of SRT as part of treatments targeting other devastating respiratory pathologies, in babies and adults, is depending on further extensive research still required before enough amounts of good humanized clinical surfactants will be available. This review summarizes our current concepts on the compositional and structural determinants defining pulmonary surfactant activity, the principles behind the development of efficient natural animal-derived or recombinant or synthetic therapeutic surfactants, as well as a the most promising lines of research that are already opening new perspectives in the application of tailored surfactant therapies to treat important yet unresolved respiratory pathologies.
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3
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Daear W, Sule K, Lai P, Prenner EJ. Biophysical analysis of gelatin and PLGA nanoparticle interactions with complex biomimetic lung surfactant models. RSC Adv 2022; 12:27918-27932. [PMID: 36320247 PMCID: PMC9523518 DOI: 10.1039/d2ra02859j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/22/2022] [Indexed: 11/21/2022] Open
Abstract
Biocompatible materials are increasingly used for pulmonary drug delivery, and it is essential to understand their potential impact on the respiratory system, notably their effect on lung surfactant, a monolayer of lipids and proteins, responsible for preventing alveolar collapse during breathing cycles. We have developed a complex mimic of lung surfactant composed of eight lipids mixed in ratios reported for native lung surfactant. A synthetic peptide based on surfactant protein B was added to better mimic the biological system. This model was used to evaluate the impact of biocompatible gelatin and poly(lactic-co-glycolic acid) nanoparticles. Surface pressure–area isotherms were used to assess lipid packing, film compressibility and stability, whereas the lateral organization was visualized by Brewster angle microscopy. Nanoparticles increased film fluidity and altered the monolayer collapse pressure. Bright protruding clusters formed in their presence indicate a significant impact on the lateral organization of the surfactant film. Altogether, this work indicates that biocompatible materials considered to be safe for drug delivery still need to be assessed for their potential detrimental impact before use in therapeutic applications Biodegradable nanoparticles drastically alters lateral organization of lung surfactant lipid- peptide model system.![]()
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Affiliation(s)
- W. Daear
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - K. Sule
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - P. Lai
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - E. J. Prenner
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
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4
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Ambroggio EE, Costa Navarro GS, Pérez Socas LB, Bagatolli LA, Gamarnik AV. Dengue and Zika virus capsid proteins bind to membranes and self-assemble into liquid droplets with nucleic acids. J Biol Chem 2021; 297:101059. [PMID: 34375636 PMCID: PMC8397897 DOI: 10.1016/j.jbc.2021.101059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/02/2022] Open
Abstract
Dengue virus (DENV) and Zika virus (ZIKV) capsid proteins efficiently recruit and surround the viral RNA at the endoplasmic reticulum (ER) membrane to yield nascent viral particles. However, little is known either about the molecular mechanisms by which multiple copies of capsid proteins assemble into nucleocapsids (NCs) or how the NC is recruited and wrapped by the ER membrane during particle morphogenesis. Here, we measured relevant interactions concerning this viral process using purified DENV and ZIKV capsid proteins, membranes mimicking the ER lipid composition, and nucleic acids in in vitro conditions to understand the biophysical properties of the RNA genome encapsidation process. We found that both ZIKV and DENV capsid proteins bound to liposomes at liquid-disordered phase regions, docked exogenous membranes, and RNA molecules. Liquid-liquid phase separation is prone to occur when positively charged proteins interact with nucleic acids, which is indeed the case for the studied capsids. We characterized these liquid condensates by measuring nucleic acid partition constants and the extent of water dipolar relaxation, observing a cooperative process for the formation of the new phase that involves a distinct water organization. Our data support a new model in which capsid-RNA complexes directly bind the ER membrane, seeding the process of RNA recruitment for viral particle assembly. These results contribute to our understanding of the viral NC formation as a stable liquid-liquid phase transition, which could be relevant for dengue and Zika gemmation, opening new avenues for antiviral intervention.
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Affiliation(s)
- Ernesto E Ambroggio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.
| | | | - Luis Benito Pérez Socas
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Luis A Bagatolli
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC (CONICET), Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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5
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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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6
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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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7
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Georgiev GA, Gh MS, Romano J, Dias Teixeira KL, Struble C, Ryan DS, Sia RK, Kitt JP, Harris JM, Hsu KL, Libby A, Odrich MG, Suárez T, McKown RL, Laurie GW. Lacritin proteoforms prevent tear film collapse and maintain epithelial homeostasis. J Biol Chem 2020; 296:100070. [PMID: 33187980 PMCID: PMC7948570 DOI: 10.1074/jbc.ra120.015833] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
Lipids in complex, protein-enriched films at air/liquid interfaces reduce surface tension. In the absence of this benefit, the light refracting and immunoprotective tear film on eyes would collapse. Premature collapse, coupled with chronic inflammation compromising visual acuity, is a hallmark of dry eye disease affecting 7 to 10% of individuals worldwide. Although collapse seems independent of mutation (unlike newborn lung alveoli), selective proteome and possible lipidome changes have been noted. These include elevated tissue transglutaminase and consequent inactivation through C-terminal cross-linking of the tear mitogen lacritin, leading to significant loss of lacritin monomer. Lacritin monomer restores homeostasis via autophagy and mitochondrial fusion and promotes basal tearing. Here, we discover that lacritin monomer C-terminal processing, inclusive of cysteine, serine, and metalloproteinase activity, generates cationic amphipathic α-helical proteoforms. Such proteoforms (using synthetic peptide surrogates) act like alveolar surfactant proteins to rapidly bind and stabilize the tear lipid layer. Immunodepletion of C- but not N-terminal proteoforms nor intact lacritin, from normal human tears promotes loss of stability akin to human dry eye tears. Stability of these and dry eye tears is rescuable with C- but not N-terminal proteoforms. Repeated topical application in rabbits reveals a proteoform turnover time of 7 to 33 h with gradual loss from human tear lipid that retains bioactivity without further processing. Thus, the processed C-terminus of lacritin that is deficient or absent in dry eye tears appears to play a key role in preventing tear film collapse and as a natural slow release mechanism that restores epithelial homeostasis.
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Affiliation(s)
- Georgi A Georgiev
- Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - Jeff Romano
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Craig Struble
- Drug Metabolism, Covance Laboratories Inc, Madison, Wisconsin, USA
| | - Denise S Ryan
- Warfighter Refractive Eye Surgery Program and Research Center at Fort Belvoir, Fort Belvoir, Virginia, USA
| | - Rose K Sia
- Warfighter Refractive Eye Surgery Program and Research Center at Fort Belvoir, Fort Belvoir, Virginia, USA
| | - Jay P Kitt
- Department of Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Joel M Harris
- Department of Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Ku-Lung Hsu
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Adam Libby
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Marc G Odrich
- Department of Ophthalmology, University of Virginia, Charlottesville, Virginia, USA
| | - Tatiana Suárez
- Department of Research, Development and Innovation, FAES FARMA, Bizkaia, Spain
| | - Robert L McKown
- Department of Integrated Science and Technology, James Madison University, Harrisonburg, Virginia, USA
| | - Gordon W Laurie
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA; Department of Ophthalmology, University of Virginia, Charlottesville, Virginia, USA; Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.
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8
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Martinez-Calle M, Prieto M, Olmeda B, Fedorov A, Loura LM, Pérez-Gil J. Pulmonary surfactant protein SP-B nanorings induce the multilamellar organization of surfactant complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183216. [DOI: 10.1016/j.bbamem.2020.183216] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/17/2020] [Accepted: 02/02/2020] [Indexed: 11/25/2022]
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9
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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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10
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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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12
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Shu L, Guo X, Niu L, Chen X, Cai T, Ding X, Xie Z, Wang J, Zhu N, Kou T, Yang F. Comprehensive characterization and proteoform analysis of the hydrophobic surfactant proteins B and C in calf pulmonary surfactant. J Pharm Biomed Anal 2019; 174:625-632. [PMID: 31276983 DOI: 10.1016/j.jpba.2019.06.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 01/11/2023]
Abstract
Calf pulmonary surfactant (CPS), which contains about 98% lipids and 2% hydrophobic surfactant proteins B (SP-B) and C (SP-C), has been used as a surfactant preparation for the clinical replacement therapy of respiratory distress syndrome (RDS). Characterization of SP-B and SP-C in CPS is informative for quality control and the evaluation of their biological activities. However, analysis of SP-B and SP-C is impeded by the high content of lipids in CPS. Here, we describe an integrated method by combining size exclusion chromatography (SEC)-based delipidation, SDS-PAGE separation, in-gel digestion and mass spectrometric analysis for comprehensive characterization and proteoform analysis of the extremely hydrophobic SP-B and SP-C in CPS. This study has shown that 30 proteoforms of SP-C with different truncations and modifications were identified and SP-B was found to be existed as a dimer form in the CPS.
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Affiliation(s)
- Lian Shu
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaojing Guo
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lili Niu
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiulan Chen
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tanxi Cai
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang Ding
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhensheng Xie
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jifeng Wang
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Nali Zhu
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tongxin Kou
- China Resources Double-crane Pharmaceutical Co. Ltd. Beijing, 100102, China
| | - Fuquan Yang
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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13
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Förster Resonance Energy Transfer as a Tool for Quantification of Protein-Lipid Selectivity. Methods Mol Biol 2019; 2003:369-382. [PMID: 31218626 DOI: 10.1007/978-1-4939-9512-7_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
This chapter addresses the determination of protein-lipid selectivity, here described as the preference of a protein for having a specific type of lipid in its vicinity, from Förster resonance energy transfer methodologies. These allow a quantification of the effect, that is, the determination of the biasing in distribution of the lipid under study around the protein, as compared to its bulk membrane distribution, with advantages over established approaches that have been used for the same purpose, such as electron spin resonance spectroscopy. The experiment can be carried out with steady-state instrumentation, the formalisms are described in detail, and the model can be applied to a membrane protein of any size.
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14
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Ronda L, Pioselli B, Catinella S, Salomone F, Marchetti M, Bettati S. Quenching of tryptophan fluorescence in a highly scattering solution: Insights on protein localization in a lung surfactant formulation. PLoS One 2018; 13:e0201926. [PMID: 30075031 PMCID: PMC6075776 DOI: 10.1371/journal.pone.0201926] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/24/2018] [Indexed: 11/18/2022] Open
Abstract
CHF5633 (Chiesi Farmaceutici, Italy) is a synthetic surfactant developed for respiratory distress syndrome replacement therapy in pre-term newborn infants. CHF5633 contains two phospholipids (dipalmitoylphosphatidylcholine and 1-palmitoyl-2oleoyl-sn-glycero-3-phosphoglycerol sodium salt), and peptide analogues of surfactant protein C (SP-C analogue) and surfactant protein B (SP-B analogue). Both proteins are fundamental for an optimal surfactant activity in vivo and SP-B genetic deficiency causes lethal respiratory failure after birth. Fluorescence emission of the only tryptophan residue present in SP-B analogue (SP-C analogue has none) could in principle be exploited to probe SP-B analogue conformation, localization and interaction with other components of the pharmaceutical formulation. However, the high light scattering activity of the multi-lamellar vesicles suspension characterizing the pharmaceutical surfactant formulation represents a challenge for such studies. We show here that quenching of tryptophan fluorescence and Singular Value Decomposition analysis can be used to accurately calculate and subtract background scattering. The results indicate, with respect to Trp microenvironment, a conformationally homogeneous population of SP-B. Trp is highly accessible to the water phase, suggesting a surficial localization on the membrane of phospholipid vesicles, similarly to what observed for full length SP-B in natural lung surfactant, and supporting an analogous role in protein anchoring to the lipid phase.
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Affiliation(s)
- Luca Ronda
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Biopharmanet-TEC, University of Parma, Parma, Italy
- * E-mail: (LR); (SB)
| | | | | | | | | | - Stefano Bettati
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Biopharmanet-TEC, University of Parma, Parma, Italy
- Italian National Institute of Biostructures and Biosystems, Rome, Italy
- * E-mail: (LR); (SB)
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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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16
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Martínez‐Calle M, Olmeda B, Dietl P, Frick M, Pérez‐Gil J. Pulmonary surfactant protein SP‐B promotes exocytosis of lamellar bodies in alveolar type II cells. FASEB J 2018. [DOI: 10.1096/fj.201701462rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Marta Martínez‐Calle
- Department of Biochemistry and Molecular BiologyFaculty of BiologyComplutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre”Complutense UniversityMadridSpain
| | - Bárbara Olmeda
- Department of Biochemistry and Molecular BiologyFaculty of BiologyComplutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre”Complutense UniversityMadridSpain
| | - Paul Dietl
- Institute of General PhysiologyUlm UniversityUlmGermany
| | - Manfred Frick
- Institute of General PhysiologyUlm UniversityUlmGermany
| | - Jesús Pérez‐Gil
- Department of Biochemistry and Molecular BiologyFaculty of BiologyComplutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre”Complutense UniversityMadridSpain
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17
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Hobi N, Giolai M, Olmeda B, Miklavc P, Felder E, Walther P, Dietl P, Frick M, Pérez-Gil J, Haller T. A small key unlocks a heavy door: The essential function of the small hydrophobic proteins SP-B and SP-C to trigger adsorption of pulmonary surfactant lamellar bodies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2124-34. [DOI: 10.1016/j.bbamcr.2016.04.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/15/2016] [Accepted: 04/27/2016] [Indexed: 02/07/2023]
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18
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Baoukina S, Tieleman DP. Computer simulations of lung surfactant. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2431-2440. [PMID: 26922885 DOI: 10.1016/j.bbamem.2016.02.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/21/2016] [Accepted: 02/23/2016] [Indexed: 01/26/2023]
Abstract
Lung surfactant lines the gas-exchange interface in the lungs and reduces the surface tension, which is necessary for breathing. Lung surfactant consists mainly of lipids with a small amount of proteins and forms a monolayer at the air-water interface connected to bilayer reservoirs. Lung surfactant function involves transfer of material between the monolayer and bilayers during the breathing cycle. Lipids and proteins are organized laterally in the monolayer; selected species are possibly preferentially transferred to bilayers. The complex 3D structure of lung surfactant and the exact roles of lipid organization and proteins remain important goals for research. We review recent simulation studies on the properties of lipid monolayers, monolayers with phase coexistence, monolayer-bilayer transformations, lipid-protein interactions, and effects of nanoparticles on lung surfactant. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
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Affiliation(s)
- Svetlana Baoukina
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.
| | - D Peter Tieleman
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.
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19
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Olmeda B, García‐Álvarez B, Gómez MJ, Martínez‐Calle M, Cruz A, Pérez‐Gil J. A model for the structure and mechanism of action of pulmonary surfactant protein B. FASEB J 2015; 29:4236-47. [DOI: 10.1096/fj.15-273458] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/15/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Bárbara Olmeda
- Departmento de Bioquímica, Facultad de BiologíaUniversidad ComplutenseMadridSpain
| | | | - Manuel J. Gómez
- Centro de Astrobiología (INTA‐CSIC), Torrejón de ArdozMadridSpain
| | - Marta Martínez‐Calle
- Departmento de Bioquímica, Facultad de BiologíaUniversidad ComplutenseMadridSpain
| | - Antonio Cruz
- Departmento de Bioquímica, Facultad de BiologíaUniversidad ComplutenseMadridSpain
| | - Jesús Pérez‐Gil
- Departmento de Bioquímica, Facultad de BiologíaUniversidad ComplutenseMadridSpain
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20
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Fernandes F, Coutinho A, Prieto M, Loura LMS. Electrostatically driven lipid-protein interaction: Answers from FRET. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1837-48. [PMID: 25769805 DOI: 10.1016/j.bbamem.2015.02.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/23/2015] [Indexed: 12/13/2022]
Abstract
Electrostatics govern the association of a large number of proteins with cellular membranes. In some cases, these proteins present specialized lipid-binding modules or membrane targeting domains while in other cases association is achieved through nonspecific interaction of unstructured clusters of basic residues with negatively charged lipids. Given its spatial resolution in the nanometer range, Förster resonance energy transfer (FRET) is a powerful tool to give insight into protein-lipid interactions and provide molecular level information which is difficult to retrieve with other spectroscopic techniques. In this review we present and discuss the basic formalisms of both hetero- and homo-FRET pertinent to the most commonly encountered problems in lipid-protein interaction studies and highlight some examples of implementations of different FRET methodologies to characterize lipid/protein systems in which electrostatic interactions play a crucial role. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Dep. Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luís M S Loura
- Faculdade de Farmácia, Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Centro de Química de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal.
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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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Composition, structure and mechanical properties define performance of pulmonary surfactant membranes and films. Chem Phys Lipids 2014; 185:153-75. [PMID: 25260665 DOI: 10.1016/j.chemphyslip.2014.09.002] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/06/2014] [Accepted: 09/11/2014] [Indexed: 12/30/2022]
Abstract
The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics of breathing and avoiding alveolar collapse, especially at the end of expiration. The goal of the present review is to summarize current knowledge regarding the structure, lipid-protein interactions and mechanical features of surfactant membranes and films and how these properties correlate with surfactant biological function inside the lungs. Surfactant mechanical properties can be severely compromised by different agents, which lead to surfactant inhibition and ultimately contributes to the development of pulmonary disorders and pathologies in newborns, children and adults. A detailed comprehension of the unique mechanical and rheological properties of surfactant layers is crucial for the diagnostics and treatment of lung diseases, either by analyzing the contribution of surfactant impairment to the pathophysiology or by improving the formulations in surfactant replacement therapies. Finally, a short review is also included on the most relevant experimental techniques currently employed to evaluate lung surfactant mechanics, rheology, and inhibition and reactivation processes.
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23
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Suárez-Germà C, Hernández-Borrell J, Prieto M, Loura LMS. Modeling FRET to investigate the selectivity of lactose permease ofEscherichia colifor lipids. Mol Membr Biol 2014; 31:120-30. [DOI: 10.3109/09687688.2014.915351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Lopez-Rodriguez E, Pérez-Gil J. Structure-function relationships in pulmonary surfactant membranes: from biophysics to therapy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1568-85. [PMID: 24525076 DOI: 10.1016/j.bbamem.2014.01.028] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/22/2014] [Accepted: 01/27/2014] [Indexed: 01/01/2023]
Abstract
Pulmonary surfactant is an essential lipid-protein complex to maintain an operative respiratory surface at the mammalian lungs. It reduces surface tension at the alveolar air-liquid interface to stabilise the lungs against physical forces operating along the compression-expansion breathing cycles. At the same time, surfactant integrates elements establishing a primary barrier against the entry of pathogens. Lack or deficiencies of the surfactant system are associated with respiratory pathologies, which treatment often includes supplementation with exogenous materials. The present review summarises current models on the molecular mechanisms of surfactant function, with particular emphasis in its biophysical properties to stabilise the lungs and the molecular alterations connecting impaired surfactant with diseased organs. It also provides a perspective on the current surfactant-based strategies to treat respiratory pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
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Affiliation(s)
- Elena Lopez-Rodriguez
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Universidad Complutense de Madrid, Madrid, Spain; Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in End Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany
| | - Jesús Pérez-Gil
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Universidad Complutense de Madrid, Madrid, Spain
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25
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Beck-Broichsitter M, Ruppert C, Schmehl T, Günther A, Seeger W. Biophysical inhibition of synthetic vs. naturally-derived pulmonary surfactant preparations by polymeric nanoparticles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:474-81. [DOI: 10.1016/j.bbamem.2013.10.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 12/24/2022]
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26
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Parra E, Alcaraz A, Cruz A, Aguilella VM, Pérez-Gil J. Hydrophobic pulmonary surfactant proteins SP-B and SP-C induce pore formation in planar lipid membranes: evidence for proteolipid pores. Biophys J 2013; 104:146-55. [PMID: 23332067 DOI: 10.1016/j.bpj.2012.11.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/14/2012] [Accepted: 11/12/2012] [Indexed: 11/24/2022] Open
Abstract
Pulmonary surfactant is a complex mixture of lipids and specific surfactant proteins, including the hydrophobic proteins SP-B and SP-C, in charge of stabilizing the respiratory surface of mammalian lungs. The combined action of both proteins is responsible for the proper structure and dynamics of membrane arrays in the pulmonary surfactant network that covers the respiratory surface. In this study, we explore the possibility that proteins SP-B and SP-C induce the permeabilization of phospholipid membranes via pore formation. To this end, electrophysiological measurements have been carried out in planar lipid membranes prepared with different lipid/protein mixtures. Our main result is that channel-like structures are detected in the presence of SP-B, SP-C, or the native mixture of both proteins. Current traces show a high variety of conductance states (from pS to nS) that are dependent both on the lipid composition and the applied potential. We also show that the type of host lipid crucially determines the ionic selectivity of the observed pores: the anionic selectivity observed in zwitterionic membranes is inverted to cationic selectivity in the presence of negatively charged lipids. All those results suggest that SP-B and SP-C proteins promote the formation of proteolipid channels in which lipid molecules are functionally involved. We propose that proteolipidic membrane-permeabilizing structures may have an important role to tune ionic and lipidic flows through the pulmonary surfactant membrane network at the alveolar surfaces.
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Affiliation(s)
- Elisa Parra
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Complutense University, Madrid, Spain
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27
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Olmeda B, García-Álvarez B, Pérez-Gil J. Structure–function correlations of pulmonary surfactant protein SP-B and the saposin-like family of proteins. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2012; 42:209-22. [DOI: 10.1007/s00249-012-0858-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 08/18/2012] [Accepted: 09/03/2012] [Indexed: 02/06/2023]
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28
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Loura LMS, Prieto M. Lateral Membrane Heterogeneity Probed by FRET Spectroscopy and Microscopy. SPRINGER SERIES ON FLUORESCENCE 2012. [DOI: 10.1007/4243_2012_59] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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