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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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2
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Chen Y, Li F, Hua M, Liang M, Song C. Role of GM-CSF in lung balance and disease. Front Immunol 2023; 14:1158859. [PMID: 37081870 PMCID: PMC10111008 DOI: 10.3389/fimmu.2023.1158859] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/24/2023] [Indexed: 04/07/2023] Open
Abstract
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor originally identified as a stimulus that induces the differentiation of bone marrow progenitor cells into granulocytes and macrophages. GM-CSF is now considered to be a multi-origin and pleiotropic cytokine. GM-CSF receptor signals activate JAK2 and induce nuclear signals through the JAK-STAT, MAPK, PI3K, and other pathways. In addition to promoting the metabolism of pulmonary surfactant and the maturation and differentiation of alveolar macrophages, GM-CSF plays a key role in interstitial lung disease, allergic lung disease, alcoholic lung disease, and pulmonary bacterial, fungal, and viral infections. This article reviews the latest knowledge on the relationship between GM-CSF and lung balance and lung disease, and indicates that there is much more to GM-CSF than its name suggests.
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Affiliation(s)
- Yingzi Chen
- Department of Immunology, School of Laboratory Medicine, Bengbu Medical College, Anhui, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases, Bengbu Medical College, Anhui, China
| | - Fan Li
- Department of Immunology, School of Laboratory Medicine, Bengbu Medical College, Anhui, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases, Bengbu Medical College, Anhui, China
| | - Mengqing Hua
- Department of Immunology, School of Laboratory Medicine, Bengbu Medical College, Anhui, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases, Bengbu Medical College, Anhui, China
| | - Meng Liang
- Department of Biotechnology, School of Life Science, Bengbu Medical College, Anhui, China
- *Correspondence: Chuanwang Song, ; Meng Liang,
| | - Chuanwang Song
- Department of Immunology, School of Laboratory Medicine, Bengbu Medical College, Anhui, China
- Anhui Province Key Laboratory of Immunology in Chronic Diseases, Bengbu Medical College, Anhui, China
- *Correspondence: Chuanwang Song, ; Meng Liang,
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Ellingsen DG, Ulvestad B, Lund MB, Skaugset NP, Sikkeland LIB. A study of pneumoproteins in crystalline silica exposed rock drillers. Inhal Toxicol 2022; 34:99-105. [PMID: 35286186 DOI: 10.1080/08958378.2022.2048745] [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: 11/05/2022]
Abstract
Objective: The objective was to assess serum concentrations of club cell protein 16 (CC-16) and the surfactant proteins A (SPs-A) and D (SP-D) in male rock drillers (N = 123) exposed to crystalline silica and in 48 occupationally non-exposed. Methods: The arithmetic mean (AM) duration of exposure was 10.7 years. The geometric mean (GM) crystalline silica exposure was 36 µg/m3 at the time of the study. The GM cumulative exposure was 239 µg/m3. Results: The concentrations of SP-D (GM 12.7 vs. 8.8 µg/L, p < 0.001) and SP-A (AM 1847 vs. 1378 ng/L, p = 0.051) were higher among rock drillers than among occupationally non-exposed. A positive significant association was observed between cumulative crystalline silica exposure and the SP-D concentrations (β = 0.07; p < 0.05). Rock drillers with small airway obstruction with maximal mid-expiratory flow % (MMEF%) <70% (N = 29) had higher SP-D concentrations than rock drillers with MMEF% ≥ 70% (N = 91) (GM 17.3 vs. 11.4 µg/L, p = 0.001). Rock drillers with MMEF% ≥70% (N = 91) had higher concentrations of SP-A (1957 vs. 1287 ng/L, p = 0.01) and SP-D (11.4 vs. 9.0 µg/L, p = 0.007) than non-exposed with MMEF% ≥70% (N = 39). Rock drillers with airway obstruction (FEV1/FVC < 0.70, N = 11) had significantly lower CC-16 concentrations than rock drillers with FEV1/FVC ≥0.70 (N = 109) after adjusting for relevant potential confounders (p = 0.02). Conclusion: The results indicate that pulmonary surfactant is a target for crystalline silica toxicity. The alterations appear to be driven by pulmonary alterations in the small airways and by exposure itself. Further studies on pneumoproteins and pulmonary function in other groups of workers exposed to crystalline silica are needed.
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Affiliation(s)
| | | | - May Britt Lund
- Department of Respiratory Medicine, Oslo University Hospital, Oslo, Norway
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Pioselli B, Salomone F, Mazzola G, Amidani D, Sgarbi E, Amadei F, Murgia X, Catinella S, Villetti G, De Luca D, Carnielli V, Civelli M. Pulmonary surfactant: a unique biomaterial with life-saving therapeutic applications. Curr Med Chem 2021; 29:526-590. [PMID: 34525915 DOI: 10.2174/0929867328666210825110421] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/26/2021] [Accepted: 06/29/2021] [Indexed: 11/22/2022]
Abstract
Pulmonary surfactant is a complex lipoprotein mixture secreted into the alveolar lumen by type 2 pneumocytes, which is composed by tens of different lipids (approximately 90% of its entire mass) and surfactant proteins (approximately 10% of the mass). It is crucially involved in maintaining lung homeostasis by reducing the values of alveolar liquid surface tension close to zero at end-expiration, thereby avoiding the alveolar collapse, and assembling a chemical and physical barrier against inhaled pathogens. A deficient amount of surfactant or its functional inactivation is directly linked to a wide range of lung pathologies, including the neonatal respiratory distress syndrome. This paper reviews the main biophysical concepts of surfactant activity and its inactivation mechanisms, and describes the past, present and future roles of surfactant replacement therapy, focusing on the exogenous surfactant preparations marketed worldwide and new formulations under development. The closing section describes the pulmonary surfactant in the context of drug delivery. Thanks to its peculiar composition, biocompatibility, and alveolar spreading capability, the surfactant may work not only as a shuttle to the branched anatomy of the lung for other drugs but also as a modulator for their release, opening to innovative therapeutic avenues for the treatment of several respiratory diseases.
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Affiliation(s)
| | | | | | | | - Elisa Sgarbi
- Preclinical R&D, Chiesi Farmaceutici, Parma. Italy
| | | | - Xabi Murgia
- Department of Biotechnology, GAIKER Technology Centre, Zamudio. Spain
| | | | | | - Daniele De Luca
- Division of Pediatrics and Neonatal Critical Care, Antoine Béclère Medical Center, APHP, South Paris University Hospitals, Paris, France; Physiopathology and Therapeutic Innovation Unit-U999, South Paris-Saclay University, Paris. France
| | - Virgilio Carnielli
- Division of Neonatology, G Salesi Women and Children's Hospital, Polytechnical University of Marche, Ancona. Italy
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Ellis SR, Hall E, Panchal M, Flinders B, Madsen J, Koster G, Heeren RMA, Clark HW, Postle AD. Mass spectrometry imaging of phosphatidylcholine metabolism in lungs administered with therapeutic surfactants and isotopic tracers. J Lipid Res 2021; 62:100023. [PMID: 33453219 PMCID: PMC7961103 DOI: 10.1016/j.jlr.2021.100023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/18/2020] [Accepted: 01/06/2021] [Indexed: 12/11/2022] Open
Abstract
Mass spectrometry imaging (MSI) visualizes molecular distributions throughout tissues but is blind to dynamic metabolic processes. Here, MSI with high mass resolution together with multiple stable isotope labeling provided spatial analyses of phosphatidylcholine (PC) metabolism in mouse lungs. Dysregulated surfactant metabolism is central to many respiratory diseases. Metabolism and turnover of therapeutic pulmonary surfactants were imaged from distributions of intact and metabolic products of an added tracer, universally 13C-labeled dipalmitoyl PC (U13C-DPPC). The parenchymal distributions of newly synthesized PC species were also imaged from incorporations of methyl-D9-choline. This dual labeling strategy demonstrated both lack of inhibition of endogenous PC synthesis by exogenous surfactant and location of acyl chain remodeling processes acting on the U13C-DPPC-labeled surfactant, leading to formation of polyunsaturated PC lipids. This ability to visualize discrete metabolic events will greatly enhance our understanding of lipid metabolism in diverse tissues and has potential application to both clinical and experimental studies.
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Affiliation(s)
- Shane R Ellis
- Division of Imaging Mass Spectrometry, Maastricht MultiModal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht, The Netherlands; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia; Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.
| | - Emily Hall
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Madhuriben Panchal
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; National Institute for Health Research Southampton Biomedical Research Centre, University Hospital Southampton, Southampton, United Kingdom
| | - Bryn Flinders
- Division of Imaging Mass Spectrometry, Maastricht MultiModal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht, The Netherlands
| | - Jens Madsen
- Elizabeth Garrett Anderson Institute for Women's Health, Faculty of Population Health Sciences, University College London, London, United Kingdom
| | - Grielof Koster
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; National Institute for Health Research Southampton Biomedical Research Centre, University Hospital Southampton, Southampton, United Kingdom
| | - Ron M A Heeren
- Division of Imaging Mass Spectrometry, Maastricht MultiModal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht, The Netherlands
| | - Howard W Clark
- Elizabeth Garrett Anderson Institute for Women's Health, Faculty of Population Health Sciences, University College London, London, United Kingdom; National Institute for Health Biomedical Research Centre, University College London Hospital Biomedical Research Centre, London, United Kingdom
| | - Anthony D Postle
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; National Institute for Health Research Southampton Biomedical Research Centre, University Hospital Southampton, Southampton, United Kingdom.
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Islam ABMMK, Khan MAAK. Lung transcriptome of a COVID-19 patient and systems biology predictions suggest impaired surfactant production which may be druggable by surfactant therapy. Sci Rep 2020; 10:19395. [PMID: 33173052 PMCID: PMC7656460 DOI: 10.1038/s41598-020-76404-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
An incomplete understanding of the molecular mechanisms behind impairment of lung pathobiology by COVID-19 complicates its clinical management. In this study, we analyzed the gene expression pattern of cells obtained from biopsies of COVID-19-affected patient and compared to the effects observed in typical SARS-CoV-2 and SARS-CoV-infected cell-lines. We then compared gene expression patterns of COVID-19-affected lung tissues and SARS-CoV-2-infected cell-lines and mapped those to known lung-related molecular networks, including hypoxia induced responses, lung development, respiratory processes, cholesterol biosynthesis and surfactant metabolism; all of which are suspected to be downregulated following SARS-CoV-2 infection based on the observed symptomatic impairments. Network analyses suggest that SARS-CoV-2 infection might lead to acute lung injury in COVID-19 by affecting surfactant proteins and their regulators SPD, SPC, and TTF1 through NSP5 and NSP12; thrombosis regulators PLAT, and EGR1 by ORF8 and NSP12; and mitochondrial NDUFA10, NDUFAF5, and SAMM50 through NSP12. Furthermore, hypoxia response through HIF-1 signaling might also be targeted by SARS-CoV-2 proteins. Drug enrichment analysis of dysregulated genes has allowed us to propose novel therapies, including lung surfactants, respiratory stimulants, sargramostim, and oseltamivir. Our study presents a distinct mechanism of probable virus induced lung damage apart from cytokine storm.
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Beck J, Miller MA, Frank C, DuSold D, Ramos-Vara JA. Surfactant Protein A and Napsin A in the Immunohistochemical Characterization of Canine Pulmonary Carcinomas: Comparison With Thyroid Transcription Factor-1. Vet Pathol 2017; 54:767-774. [PMID: 28578631 DOI: 10.1177/0300985817712559] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thyroid transcription factor-1 (TTF-1) is a specific and sensitive marker for canine pulmonary tumors but is also expressed in thyroid carcinomas, which commonly metastasize to lung. Napsin A and surfactant protein A (SP-A) are used in the histologic diagnosis of non-small-cell lung cancer in humans but have not been thoroughly evaluated in neoplasms of dogs. The objective of this study was to compare the efficacy of immunohistochemistry for SP-A, napsin A, and TTF-1 in the diagnosis of canine pulmonary carcinomas. TTF-1, napsin A, and SP-A antibodies were applied to 67 formalin-fixed, paraffin-embedded canine pulmonary tumors. Although each marker had good sensitivity, only 3% (2/67) of lung tumors were negative for SP-A compared with 7% (5/67) and 9% (6/67) for napsin A and TTF-1, respectively. Each antigen was detected in a greater percentage of cells of tumors with acinar or papillary patterns compared with those with squamous differentiation. SP-A immunoreactivity was absent in all 113 nonpulmonary tumors tested. Of 108 normal tissues, SP-A was detected only in lung and in 1 of 6 adrenal, 1 of 3 endometrial, and 1 of 4 hepatic sections. Based on these findings, SP-A and napsin A are useful markers of canine lung epithelial neoplasia. Of these, SP-A is the most sensitive and specific (a possible pitfall is the need to distinguish entrapped normal pulmonary epithelial cells or alveolar macrophages from neoplastic cells) and can be used in combination with TTF-1 or napsin A to improve detection and differentiation of pulmonary carcinomas from metastatic tumors in the canine lung.
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Affiliation(s)
- Jessica Beck
- 1 Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, USA.,2 Laboratory of Human Carcinogenesis, National Cancer Institute, Bethesda, MD, USA
| | - Margaret A Miller
- 1 Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, USA
| | - Chad Frank
- 3 Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Dee DuSold
- 1 Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, USA
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Brown K, Filuta A, Ludwig MG, Seuwen K, Jaros J, Vidal S, Arora K, Naren AP, Kandasamy K, Parthasarathi K, Offermanns S, Mason RJ, Miller WE, Whitsett JA, Bridges JP. Epithelial Gpr116 regulates pulmonary alveolar homeostasis via Gq/11 signaling. JCI Insight 2017; 2:93700. [PMID: 28570277 DOI: 10.1172/jci.insight.93700] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/02/2017] [Indexed: 12/27/2022] Open
Abstract
Pulmonary function is dependent upon the precise regulation of alveolar surfactant. Alterations in pulmonary surfactant concentrations or function impair ventilation and cause tissue injury. Identification of the molecular pathways that sense and regulate endogenous alveolar surfactant concentrations, coupled with the ability to pharmacologically modulate them both positively and negatively, would be a major therapeutic advance for patients with acute and chronic lung diseases caused by disruption of surfactant homeostasis. The orphan adhesion GPCR GPR116 (also known as Adgrf5) is a critical regulator of alveolar surfactant concentrations. Here, we show that human and mouse GPR116 control surfactant secretion and reuptake in alveolar type II (AT2) cells by regulating guanine nucleotide-binding domain α q and 11 (Gq/11) signaling. Synthetic peptides derived from the ectodomain of GPR116 activated Gq/11-dependent inositol phosphate conversion, calcium mobilization, and cortical F-actin stabilization to inhibit surfactant secretion. AT2 cell-specific deletion of Gnaq and Gna11 phenocopied the accumulation of surfactant observed in Gpr116-/- mice. These data provide proof of concept that GPR116 is a plausible therapeutic target to modulate endogenous alveolar surfactant pools to treat pulmonary diseases associated with surfactant dysfunction.
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Affiliation(s)
- Kari Brown
- Department of Pediatrics, Perinatal Institute, Section of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Alyssa Filuta
- Department of Pediatrics, Perinatal Institute, Section of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | | | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Julian Jaros
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Solange Vidal
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Kavisha Arora
- Department of Pediatrics, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Anjaparavanda P Naren
- Department of Pediatrics, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Kathirvel Kandasamy
- Department of Physiology, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Kaushik Parthasarathi
- Department of Physiology, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Robert J Mason
- Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - William E Miller
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jeffrey A Whitsett
- Department of Pediatrics, Perinatal Institute, Section of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - James P Bridges
- Department of Pediatrics, Perinatal Institute, Section of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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Saito A, Nikolaidis NM, Amlal H, Uehara Y, Gardner JC, LaSance K, Pitstick LB, Bridges JP, Wikenheiser-Brokamp KA, McGraw DW, Woods JC, Sabbagh Y, Schiavi SC, Altinişik G, Jakopović M, Inoue Y, McCormack FX. Modeling pulmonary alveolar microlithiasis by epithelial deletion of the Npt2b sodium phosphate cotransporter reveals putative biomarkers and strategies for treatment. Sci Transl Med 2016; 7:313ra181. [PMID: 26560359 DOI: 10.1126/scitranslmed.aac8577] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pulmonary alveolar microlithiasis (PAM) is a rare, autosomal recessive lung disorder associated with progressive accumulation of calcium phosphate microliths. Inactivating mutations in SLC34A2, which encodes the NPT2b sodium-dependent phosphate cotransporter, has been proposed as a cause of PAM. We show that epithelial deletion of Npt2b in mice results in a progressive pulmonary process characterized by diffuse alveolar microlith accumulation, radiographic opacification, restrictive physiology, inflammation, fibrosis, and an unexpected alveolar phospholipidosis. Cytokine and surfactant protein elevations in the alveolar lavage and serum of PAM mice and confirmed in serum from PAM patients identify serum MCP-1 (monocyte chemotactic protein 1) and SP-D (surfactant protein D) as potential biomarkers. Microliths introduced by adoptive transfer into the lungs of wild-type mice produce marked macrophage-rich inflammation and elevation of serum MCP-1 that peaks at 1 week and resolves at 1 month, concomitant with clearance of stones. Microliths isolated by bronchoalveolar lavage readily dissolve in EDTA, and therapeutic whole-lung EDTA lavage reduces the burden of stones in the lungs. A low-phosphate diet prevents microlith formation in young animals and reduces lung injury on the basis of reduction in serum SP-D. The burden of pulmonary calcium deposits in established PAM is also diminished within 4 weeks by a low-phosphate diet challenge. These data support a causative role for Npt2b in the pathogenesis of PAM and the use of the PAM mouse model as a preclinical platform for the development of biomarkers and therapeutic strategies.
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Affiliation(s)
- Atsushi Saito
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Nikolaos M Nikolaidis
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Hassane Amlal
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Yasuaki Uehara
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jason C Gardner
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Kathleen LaSance
- Vontz Core Imaging Laboratory, Vontz Center for Molecular Studies, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Lori B Pitstick
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - James P Bridges
- Perinatal Institute, Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | | | - Dennis W McGraw
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jason C Woods
- Pulmonary Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Yves Sabbagh
- The Sanofi-Genzyme R&D Center, Genzyme, a Sanofi company, Framingham, MA 01701, USA
| | - Susan C Schiavi
- The Sanofi-Genzyme R&D Center, Genzyme, a Sanofi company, Framingham, MA 01701, USA
| | - Göksel Altinişik
- Department of Chest Diseases, Faculty of Medicine, Pamukkale University, Denizli 20160, Turkey
| | - Marko Jakopović
- Department for Respiratory Diseases, University Hospital Centre Zagreb, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Yoshikazu Inoue
- Department of Diffuse Lung Diseases and Respiratory Failure, Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Osaka 5918555, Japan
| | - Francis X McCormack
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA.
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Facco M, Nespeca M, Simonato M, Isak I, Verlato G, Ciambra G, Giorgetti C, Carnielli VP, Cogo PE. In vivo effect of pneumonia on surfactant disaturated-phosphatidylcholine kinetics in newborn infants. PLoS One 2014; 9:e93612. [PMID: 25551219 PMCID: PMC4281094 DOI: 10.1371/journal.pone.0093612] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 03/03/2014] [Indexed: 01/17/2023] Open
Abstract
Background Bacterial pneumonia in newborns often leads to surfactant deficiency or dysfunction, as surfactant is inactivated or its production/turnover impaired. No data are available in vivo in humans on the mechanism of surfactant depletion in neonatal pneumonia. We studied the kinetics of surfactant's major component, disaturated-phosphatidylcholine (DSPC), in neonatal pneumonia, and we compared our findings with those obtained from control newborn lungs. Methods We studied thirty-one term or near-term newborns (gestational age 39.7±1.7 weeks, birth weight 3185±529 g) requiring mechanical ventilation. Fifteen newborns had pneumonia, while 16 newborns were on mechanical ventilation but had no lung disease. Infants received an intratracheal dose of 13C labeled dipalmitoyl-phosphatidylcholine at the study start. We measured the amount and the isotopic enrichment of DSPC-palmitate from serial tracheal aspirates by gas chromatography and gas chromatography-mass spectrometry, respectively, and we calculated the DSPC half-life (HL) and pool size (PS) from the isotopic enrichment curves of surfactant DSPC-palmitate. Results The mean DSPC amount obtained from all tracheal aspirates did not differ between the two groups. DSPC HL was 12.7 (6.5–20.2) h and 25.6 (17.9–60.6) h in infants with pneumonia compared with control infants (p = 0.003). DSPC PS was 14.1 (6.6–30.9) mg/kg in infants with pneumonia and 34.1 (25.6–65.0) mg/kg in controls, p = 0.042. Myeloperoxidase (MPO) activity, as a marker of lung inflammation, was 1322 (531–2821) mU/ml of Epithelial Lining Fluid (ELF) and 371(174–1080) mU/ml ELF in infants with pneumonia and in controls, p = 0.047. In infants with pneumonia, DSPC PS and HL significantly and inversely correlated with mean Oxygenation Index (OI) during the study (DSPC PS vs. OI R = −0.710, p = 0.004 and HL vs. OI R = −0.525, p = 0.044, respectively). Conclusions We demonstrated for the first time in vivo in humans that DSPC HL and PS were markedly impaired in neonatal pneumonia and that they inversely correlated with the degree of respiratory failure.
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Affiliation(s)
- Maddalena Facco
- Department of Women's and Children's Health, University of Padua, Padua, Italy
- * E-mail:
| | - Matteo Nespeca
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Manuela Simonato
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Ilena Isak
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Giovanna Verlato
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Gianluca Ciambra
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Chiara Giorgetti
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Virgilio P. Carnielli
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Paola E. Cogo
- Pediatric Cardiac Anesthesia/Intensive Care Unit, Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children's Hospital, Rome, Italy
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11
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Bersani I, Speer CP, Kunzmann S. Surfactant proteins A and D in pulmonary diseases of preterm infants. Expert Rev Anti Infect Ther 2014; 10:573-84. [DOI: 10.1586/eri.12.34] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Lamonica G, Amigoni M, Vedovelli L, Zambelli V, Scanziani M, Bellani G, Grassi A, Simonato M, Carnielli VP, Cogo PE. Pulmonary surfactant synthesis after unilateral lung injury in mice. J Appl Physiol (1985) 2013; 116:210-5. [PMID: 24336880 DOI: 10.1152/japplphysiol.01535.2012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Aspiration pneumonitis can lead to alveolar surfactant dysfunction. We employed a murine model of unilateral aspiration to compare surfactant synthesis in the injured (I) and noninjured (NI) contralateral lung. Mice were instilled with hydrochloric acid in the right bronchus and, after 18 h, an intraperitoneal dose of deuterated water was administered as precursor of disaturated phosphatidylcholine (DSPC)-palmitate. Selected bronchoalveolar lavage fluid (BALF) was collected at scheduled time points and lungs were removed. We measured DSPC-palmitate synthesis in lung tissue and secretion in BALF by gas chromatography-isotope ratio mass spectrometry, together with total proteins and myeloperoxidase activity (MPO) by spectrophotometry. BALF total proteins and MPO were significantly increased in the I lungs compared with NI and naïve control lungs. The DSPC pool size was significantly lower in the BALF of the I lungs compared with naïve controls. DSPC synthesis was accelerated in the I and NI lungs. DSPC secretion of the I lungs was similar to their respective naïve controls, and it was markedly lower compared with their respective NI contralateral lungs. DSPC synthesis and secretion were faster, especially in the NI lungs, compared with naïve control lungs, as a possible compensatory mechanism due to a cross-talk between the lungs triggered by inflammation, hyperventilation, and/or undetermined type II cell reaction to the injury.
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Affiliation(s)
- Giulia Lamonica
- Department of Woman and Child Health, University of Padova, Padova, Italy
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Bridges JP, Ludwig MG, Mueller M, Kinzel B, Sato A, Xu Y, Whitsett JA, Ikegami M. Orphan G protein-coupled receptor GPR116 regulates pulmonary surfactant pool size. Am J Respir Cell Mol Biol 2013; 49:348-57. [PMID: 23590306 DOI: 10.1165/rcmb.2012-0439oc] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Pulmonary surfactant levels within the alveoli are tightly regulated to maintain lung volumes and promote efficient gas exchange across the air/blood barrier. Quantitative and qualitative abnormalities in surfactant are associated with severe lung diseases in children and adults. Although the cellular and molecular mechanisms that control surfactant metabolism have been studied intensively, the critical molecular pathways that sense and regulate endogenous surfactant levels within the alveolus have not been identified and constitute a fundamental knowledge gap in the field. In this study, we demonstrate that expression of an orphan G protein-coupled receptor, GPR116, in the murine lung is developmentally regulated, reaching maximal levels 1 day after birth, and is highly expressed on the apical surface of alveolar type I and type II epithelial cells. To define the physiological role of GPR116 in vivo, mice with a targeted mutation of the Gpr116 locus, Gpr116(Δexon17), were generated. Gpr116(Δexon17) mice developed a profound accumulation of alveolar surfactant phospholipids at 4 weeks of age (12-fold) that was further increased at 20 weeks of age (30-fold). Surfactant accumulation in Gpr116(Δexon17) mice was associated with increased saturated phosphatidylcholine synthesis at 4 weeks and the presence of enlarged, lipid-laden macrophages, neutrophilia, and alveolar destruction at 20 weeks. mRNA microarray analyses indicated that P2RY2, a purinergic receptor known to mediate surfactant secretion, was induced in Gpr116(Δexon17) type II cells. Collectively, these data support the concept that GPR116 functions as a molecular sensor of alveolar surfactant lipid pool sizes by regulating surfactant secretion.
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Affiliation(s)
- James P Bridges
- Perinatal Institute, Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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Agassandian M, Mallampalli RK. Surfactant phospholipid metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:612-25. [PMID: 23026158 DOI: 10.1016/j.bbalip.2012.09.010] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/07/2012] [Accepted: 09/16/2012] [Indexed: 12/16/2022]
Abstract
Pulmonary surfactant is essential for life and is composed of a complex lipoprotein-like mixture that lines the inner surface of the lung to prevent alveolar collapse at the end of expiration. The molecular composition of surfactant depends on highly integrated and regulated processes involving its biosynthesis, remodeling, degradation, and intracellular trafficking. Despite its multicomponent composition, the study of surfactant phospholipid metabolism has focused on two predominant components, disaturated phosphatidylcholine that confers surface-tension lowering activities, and phosphatidylglycerol, recently implicated in innate immune defense. Future studies providing a better understanding of the molecular control and physiological relevance of minor surfactant lipid components are needed. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.
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Affiliation(s)
- Marianna Agassandian
- Department of Medicine, Acute Lung Injury Center of Excellence, the University of Pittsburgh, Pittsburgh, PA 15213, USA
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Lu TH, Chen CH, Lee MJ, Ho TJ, Leung YM, Hung DZ, Yen CC, He TY, Chen YW. Methylmercury chloride induces alveolar type II epithelial cell damage through an oxidative stress-related mitochondrial cell death pathway. Toxicol Lett 2010; 194:70-8. [PMID: 20153410 DOI: 10.1016/j.toxlet.2010.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Revised: 02/03/2010] [Accepted: 02/04/2010] [Indexed: 11/16/2022]
Abstract
Mercury, one of the widespread pollutants in the world, induces oxidative stress and dysfunction in many cell types. Alveolar type II epithelial cells are known to be vulnerable to oxidative stress. Alveolar type II epithelial cells produce and secrete surfactants to maintain morphological organization, biophysical functions, biochemical composition, and immunity in lung tissues. However, the precise action and mechanism of mercury on alveolar type II epithelial cell damage remains unclear. In this study, we investigate the effect and possible mechanism of methylmercury chloride (MeHgCl) on the human lung invasive carcinoma cell line (Cl1-0) and mouse lung tissue. Cl1-0 cells were exposed to MeHgCl (2.5-10 microM) for 24-72 h. The results showed a decrease in cell viability and an increase in malondialdehyde (MDA) level and ROS production at 72 h after MeHgCl exposure in a dose-dependent manner. Caspase-3 activity, sub-G1 contents and annexin-V binding were dramatically enhanced in Cl1-0 cells treated with MeHgCl. MeHgCl could also activate Bax, release cytochrome c, and cleave poly(ADP-Ribose) polymerase (PARP), and decrease surfactant proteins mRNA levels. Moreover, in vivo study showed that mercury contents of blood and lung tissues were significantly increased after MeHgCl treatment in mice. The MDA levels in plasma and lung tissues were also dramatically raised after MeHgCl treatment. Lung tissue sections of MeHgCl-treated mice showed pathological fibrosis as compared with vehicle control. The mRNA levels of proteins in apoptotic signaling, including p53, mdm-2, Bax, Bad, and caspase-3 were increased in mice after exposure to MeHgCl. In addition, the mRNA levels of surfactant proteins (SPs), namely, SP-A, SP-B, SP-C, and SP-D (alveolar epithelial cell functional markers) were significantly decreased. These results suggest that MeHgCl activates an oxidative stress-induced mitochondrial cell death in alveolar epithelial cells.
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Affiliation(s)
- Tien Hui Lu
- Department of Nutrition, College of Health Care, China Medical University, Taichung, Taiwan
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Schleh C, Mühlfeld C, Pulskamp K, Schmiedl A, Nassimi M, Lauenstein HD, Braun A, Krug N, Erpenbeck VJ, Hohlfeld JM. The effect of titanium dioxide nanoparticles on pulmonary surfactant function and ultrastructure. Respir Res 2009; 10:90. [PMID: 19793393 PMCID: PMC2765946 DOI: 10.1186/1465-9921-10-90] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Accepted: 09/30/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pulmonary surfactant reduces surface tension and is present at the air-liquid interface in the alveoli where inhaled nanoparticles preferentially deposit. We investigated the effect of titanium dioxide (TiO(2)) nanosized particles (NSP) and microsized particles (MSP) on biophysical surfactant function after direct particle contact and after surface area cycling in vitro. In addition, TiO(2) effects on surfactant ultrastructure were visualized. METHODS A natural porcine surfactant preparation was incubated with increasing concentrations (50-500 microg/ml) of TiO(2) NSP or MSP, respectively. Biophysical surfactant function was measured in a pulsating bubble surfactometer before and after surface area cycling. Furthermore, surfactant ultrastructure was evaluated with a transmission electron microscope. RESULTS TiO(2) NSP, but not MSP, induced a surfactant dysfunction. For TiO(2) NSP, adsorption surface tension (gammaads) increased in a dose-dependent manner from 28.2 + or - 2.3 mN/m to 33.2 + or - 2.3 mN/m (p < 0.01), and surface tension at minimum bubble size (gammamin) slightly increased from 4.8 + or - 0.5 mN/m up to 8.4 + or - 1.3 mN/m (p < 0.01) at high TiO(2) NSP concentrations. Presence of NSP during surface area cycling caused large and significant increases in both gammaads (63.6 + or - 0.4 mN/m) and gammamin (21.1 + or - 0.4 mN/m). Interestingly, TiO(2) NSP induced aberrations in the surfactant ultrastructure. Lamellar body like structures were deformed and decreased in size. In addition, unilamellar vesicles were formed. Particle aggregates were found between single lamellae. CONCLUSION TiO(2) nanosized particles can alter the structure and function of pulmonary surfactant. Particle size and surface area respectively play a critical role for the biophysical surfactant response in the lung.
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Affiliation(s)
- Carsten Schleh
- Fraunhofer Institute of Toxicology and Experimental Medicine, Division of Immunology, Allergology and Airway Research, Nikolai-Fuchs-Str, 1, 30625 Hannover, Germany.
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Ikegami M, Grant S, Korfhagen T, Scheule RK, Whitsett JA. Surfactant protein-D regulates the postnatal maturation of pulmonary surfactant lipid pool sizes. J Appl Physiol (1985) 2009; 106:1545-52. [PMID: 19265061 DOI: 10.1152/japplphysiol.91567.2008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surfactant protein (SP)-D plays an important role in host defense and pulmonary surfactant homeostasis. In SP-D-deficient (Sftpd(-/-)) mice, the abnormal large surfactant forms seen at the ultrastructural level are taken up inefficiently by type II cells, resulting in an over threefold increase in the surfactant pool size. The mechanisms by which SP-D influences surfactant ultrastructure are unknown. We hypothesized that SP-D binds to surfactant immediately after being secreted and influences surfactant ultrastructure conversion. In newborn and adult sheep lungs, immunogold-labeled SP-D was associated with both lamellated membranous lipid structures of newly secreted surfactant and with small aggregate surfactant but not with tubular myelin. Since SP-D preferentially binds to phosphatidylinositol (PI) in vitro, the postnatal changes in PI were assessed. PI content in the bronchoalveolar lavage fluid increased after birth and peaked at 2-5 days of age, a time of rapid conversion of surfactant forms that is associated with the peak of surfactant lipid pool size. SP-D selectively interacted with PI-rich liposomes in vitro, causing their lysis. Similarly, the abnormal surfactant ultrastructure in Sftpd(-/-) mice was corrected by the addition of SP-D or melittin, and both peptides caused lysis of lipid vesicles. The normal conversion of surfactant ultrastructure requires SP-D that preferentially interacts with PI-rich, newly secreted surfactant, causing lysis of surfactant lipid membranes, converting the lipid forms into smaller surfactant lamellated structures that are critical for surfactant uptake by type II cells and normal surfactant homeostasis. SP-D regulates the dramatic decreases in the surfactant pool size that occurs in the newborn period.
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Affiliation(s)
- Machiko Ikegami
- Div. of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, ML #7029, 3333 Burnet Ave., Cincinnati, Ohio 45229-3039, USA.
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Abstract
Pulmonary pathology includes a large spectrum of both neoplastic and non-neoplastic diseases that affect the lung. Many of these are a result of the unusual relationship of the lung with the outside world. Every breath that a human takes brings the outside world into the body in the form of infectious agents, organic and inorganic particles, and noxious agents of all types. Although the lung has many defense mechanisms to protect itself from these insults, these are not infallible; therefore, lung pathology arises. Damage to the lung is particularly important given the role of the lung in the survival of the organism. Any impairment of lung function has widespread effects throughout the body, since all organs depend on the lungs for the oxygen they need. Pulmonary pathology catalogs the changes in the lung tissues and the mechanisms through which these occur. This chapter presents a review of lung pathology and the current state of knowledge about the pathogenesis of each disease. It suggests that a clear understanding of both morphology and mechanism is required for the development of new therapies and preventive measures.
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Wojcik AJ, Skaflen MD, Srinivasan S, Hedrick CC. A critical role for ABCG1 in macrophage inflammation and lung homeostasis. THE JOURNAL OF IMMUNOLOGY 2008; 180:4273-82. [PMID: 18322240 DOI: 10.4049/jimmunol.180.6.4273] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
ATP-binding cassette transporter G1 (ABCG1) effluxes cholesterol from macrophages and plays an important role in pulmonary lipid homeostasis. We hypothesize that macrophages from Abcg1(-/-) mice have increased inflammatory activity, thereby promoting acceleration of pulmonary disease. We herein demonstrate increased numbers of inflammatory cytokines and infiltrating neutrophils, eosinophils, dendritic cells, T cells, and B cells into lungs of Abcg1(-/-) mice before the onset of severe lipidosis. We further investigated the role of macrophages in causing pulmonary disease by performing bone marrow transplantations using B6 and Abcg1(-/-) bone marrow. We found that it was the macrophage, and not pneumocyte type II cells or other nonhematopoietic cells in the lung, that appeared to be the primary cell type involved in the onset of both pulmonary lipidosis and inflammation in the Abcg1(-/-) mice. Additionally, our results demonstrate that Abcg1(-/-) macrophages had elevated proinflammatory cytokine production, increased apoptotic cell clearance, and were themselves more prone to apoptosis and necrosis. However, they were quickly repopulated by monocytes that were recruited to Abcg1(-/-) lungs. In conclusion, we have shown that ABCG1 deletion in macrophages causes a striking inflammatory phenotype and initiates onset of pulmonary lipidosis in mice. Thus, our studies reveal a critical role for macrophage ABCG1 in lung inflammation and homeostasis.
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Affiliation(s)
- Allison J Wojcik
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
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Hansen S, Schmidt V, Steffensen MA, Jensen PH, Gjerstorff M, Thiel S, Holmskov U. An enzyme-linked immunosorbent assay (ELISA) for quantification of mouse surfactant protein D (SP-D). J Immunol Methods 2008; 330:75-85. [DOI: 10.1016/j.jim.2007.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 10/05/2007] [Accepted: 11/01/2007] [Indexed: 12/19/2022]
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