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Zhu Y, Choi D, Somanath PR, Zhang D. Lipid-Laden Macrophages in Pulmonary Diseases. Cells 2024; 13:889. [PMID: 38891022 PMCID: PMC11171561 DOI: 10.3390/cells13110889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/20/2024] Open
Abstract
Pulmonary surfactants play a crucial role in managing lung lipid metabolism, and dysregulation of this process is evident in various lung diseases. Alternations in lipid metabolism lead to pulmonary surfactant damage, resulting in hyperlipidemia in response to lung injury. Lung macrophages are responsible for recycling damaged lipid droplets to maintain lipid homeostasis. The inflammatory response triggered by external stimuli such as cigarette smoke, bleomycin, and bacteria can interfere with this process, resulting in the formation of lipid-laden macrophages (LLMs), also known as foamy macrophages. Recent studies have highlighted the potential significance of LLM formation in a range of pulmonary diseases. Furthermore, growing evidence suggests that LLMs are present in patients suffering from various pulmonary conditions. In this review, we summarize the essential metabolic and signaling pathways driving the LLM formation in chronic obstructive pulmonary disease, pulmonary fibrosis, tuberculosis, and acute lung injury.
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Affiliation(s)
- Yin Zhu
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA 30912, USA (D.C.)
- Charlie Norwood VA Medical Center, Augusta, GA 30912, USA
| | - Dooyoung Choi
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA 30912, USA (D.C.)
| | - Payaningal R. Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA 30912, USA (D.C.)
- Charlie Norwood VA Medical Center, Augusta, GA 30912, USA
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Duo Zhang
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA 30912, USA (D.C.)
- Charlie Norwood VA Medical Center, Augusta, GA 30912, USA
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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2
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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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3
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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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4
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Vahdatpour C, Khasawneh M, Zayed Y, Ataya A. Emerging Medical Therapies for Pulmonary Alveolar Proteinosis. Am J Respir Crit Care Med 2021; 203:1566-1568. [PMID: 33891826 DOI: 10.1164/rccm.202011-4260rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Cyrus Vahdatpour
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida
| | - Majd Khasawneh
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida
| | - Yazan Zayed
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida
| | - Ali Ataya
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida
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5
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Lugg ST, Scott A, Parekh D, Naidu B, Thickett DR. Cigarette smoke exposure and alveolar macrophages: mechanisms for lung disease. Thorax 2021; 77:94-101. [PMID: 33986144 PMCID: PMC8685655 DOI: 10.1136/thoraxjnl-2020-216296] [Citation(s) in RCA: 128] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/17/2022]
Abstract
Cigarette smoking is the leading cause of preventable death worldwide. It causes chronic lung disease and predisposes individuals to acute lung injury and pulmonary infection. Alveolar macrophages are sentinel cells strategically positioned in the interface between the airway lumen and the alveolar spaces. These are the most abundant immune cells and are the first line of defence against inhaled particulates and pathogens. Recently, there has been a better understanding about the ontogeny, phenotype and function of alveolar macrophages and their role, not only in phagocytosis, but also in initiating and resolving immune response. Many of the functions of the alveolar macrophage have been shown to be dysregulated following exposure to cigarette smoke. While the mechanisms for these changes remain poorly understood, they are important in the understanding of cigarette smoking-induced lung disease. We review the mechanisms by which smoking influences alveolar macrophage: (1) recruitment, (2) phenotype, (3) immune function (bacterial killing, phagocytosis, proteinase/anti-proteinase release and reactive oxygen species production) and (4) homeostasis (surfactant/lipid processing, iron homeostasis and efferocytosis). Further understanding of the mechanisms of cigarette smoking on alveolar macrophages and other lung monocyte/macrophage populations may allow novel ways of restoring cellular function in those patients who have stopped smoking in order to reduce the risk of subsequent infection or further lung injury.
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Affiliation(s)
- Sebastian T Lugg
- Birmingham Acute Care Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - Aaron Scott
- Birmingham Acute Care Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - Dhruv Parekh
- Birmingham Acute Care Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - Babu Naidu
- Birmingham Acute Care Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - David R Thickett
- Birmingham Acute Care Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
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6
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Yan X, Gao Y, Zhao Q, Qiu X, Tian M, Dai J, Zhuang Y. Correlation of Lipid Ratios With the Severity of Pulmonary Alveolar Proteinosis: A Cross-Sectional Study. Front Nutr 2021; 8:610765. [PMID: 33816536 PMCID: PMC8012728 DOI: 10.3389/fnut.2021.610765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/04/2021] [Indexed: 12/22/2022] Open
Abstract
Background: Lipids are known to accumulate abnormally in the alveoli and circulate during pulmonary alveolar proteinosis (PAP). However, the relationship between lipid ratios and PAP is not clear. In this study, we investigated the lipid ratios in PAP patients and explored the relationships between lipid ratios and the severity of PAP. Methods: A total of 122 PAP patients were diagnosed and divided the mild- moderate PAP group (n = 61) and the severe PAP group (n = 61) according to the value of disease severity score (DSS). One hundred thirty healthy volunteers were classified as the control group. Routine blood examination and pulmonary function tests were performed and lipid profile were measured. Results: Compared with the control group, patients with PAP had significantly higher TG, TC/HDL-C, TG/HDL-C, and non-HDL-C, while lower HDL-C (all P < 0.05). Patients with the severe PAP had higher TC, TG, LDL-C, TC/HDL-C, and non-HDL-C, while lower HDL-C than patients with the mild- moderate PAP (all P < 0.05). Binary logistic regression analysis indicated that TC/HDL-C (OR = 2.322, 95% CI 1.621–3.713, P = 0.024) and non-HDL-C (OR = 1.797, 95% CI 1.239–3.109, P = 0.036) were all significantly correlated with the severity of PAP after adjustment for other risk factors. The AUC value of TC/HDL-C for predicting the severity of PAP was larger than that of non-HDL-C. The AUROC for TC/HDL-C was 0.741 (0.654–0.828), and the optimal cut-off point for TC/HDL-C was 5.05 (sensitivity: 73.6%, specificity: 68.1%). Conclusions: Lipid ratios, including TC-HDL-C and non-HDL-C, were independent risk factors for the severity of PAP. TC/HDL-C is a promising biomarker for the severity of PAP.
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Affiliation(s)
- Xin Yan
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Yujuan Gao
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Qi Zhao
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Xiaohua Qiu
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Mi Tian
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Jinghong Dai
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Yi Zhuang
- Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
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7
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Statin as a novel pharmacotherapy of pulmonary alveolar proteinosis. Nat Commun 2018; 9:3127. [PMID: 30087322 PMCID: PMC6081448 DOI: 10.1038/s41467-018-05491-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/22/2018] [Indexed: 12/20/2022] Open
Abstract
Pulmonary alveolar proteinosis (PAP) is a syndrome of reduced GM-CSF-dependent, macrophage-mediated surfactant clearance, dysfunctional foamy alveolar macrophages, alveolar surfactant accumulation, and hypoxemic respiratory failure for which the pathogenetic mechanism is unknown. Here, we examine the lipids accumulating in alveolar macrophages and surfactant to define the pathogenesis of PAP and evaluate a novel pharmacotherapeutic approach. In PAP patients, alveolar macrophages have a marked increase in cholesterol but only a minor increase in phospholipids, and pulmonary surfactant has an increase in the ratio of cholesterol to phospholipids. Oral statin therapy is associated with clinical, physiological, and radiological improvement in autoimmune PAP patients, and ex vivo statin treatment reduces cholesterol levels in explanted alveolar macrophages. In Csf2rb−/− mice, statin therapy reduces cholesterol accumulation in alveolar macrophages and ameliorates PAP, and ex vivo statin treatment increases cholesterol efflux from macrophages. These results support the feasibility of statin as a novel pathogenesis-based pharmacotherapy of PAP. Pulmonary alveolar proteinosis (PAP) is associated with defective macrophage clearance of surfactant. Here, the authors show that patients with PAP have altered cholesterol-to-phospholipid ratio in their surfactant, and that more importantly, statin therapy and reduction of cholesterol accumulation in macrophages can ameliorate PAP in both humans and mice.
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8
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Soyez B, Borie R, Menard C, Cadranel J, Chavez L, Cottin V, Gomez E, Marchand-Adam S, Leroy S, Naccache JM, Nunes H, Reynaud-Gaubert M, Savale L, Tazi A, Wemeau-Stervinou L, Debray MP, Crestani B. Rituximab for auto-immune alveolar proteinosis, a real life cohort study. Respir Res 2018; 19:74. [PMID: 29695229 PMCID: PMC5918901 DOI: 10.1186/s12931-018-0780-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/16/2018] [Indexed: 12/16/2022] Open
Abstract
Background Whole lung lavage is the current standard therapy for pulmonary alveolar proteinosis (PAP) that is characterized by the alveolar accumulation of surfactant. Rituximab showed promising results in auto-immune PAP (aPAP) related to anti-GM-CSF antibody. Methods We aimed to assess efficacy of rituximab in aPAP in real life and all patients with aPAP in France that received rituximab were retrospectively analyzed. Results Thirteen patients were included. No patients showed improvement 6 months after treatment, but, 4 patients (30%) presented a significant decrease of alveolar-arterial difference in oxygen after 1 year. One patient received lung transplantation and one patient was lost of follow-up within one year. Although a spontaneous improvement cannot be excluded in these 4 patients, improvement was more frequent in patients naïve to prior specific therapy and with higher level of anti-GM-CSF antibodies evaluated by ELISA. No serious adverse event was evidenced. Conclusions These data do not support rituximab as a second line therapy for patients with refractory aPAP.
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Affiliation(s)
- Berenice Soyez
- Service de Pneumologie A, DHU FIRE, centre de référence constitutif des maladies pulmonaires rares, Hôpital Bichat, APHP, 46 rue Henri Huchard 75877 Paris CEDEX, 18, Paris, France.,OrphaLung, Lyon, France.,Service de Pneumologie, Hôpital de la Pitié Salpetrière, APHP, Paris, France
| | - Raphael Borie
- Service de Pneumologie A, DHU FIRE, centre de référence constitutif des maladies pulmonaires rares, Hôpital Bichat, APHP, 46 rue Henri Huchard 75877 Paris CEDEX, 18, Paris, France. .,OrphaLung, Lyon, France. .,INSERM, Unité 1152, Université Paris Diderot, Paris, France.
| | - Cedric Menard
- Service d'Immunologie, Thérapie Cellulaire et Hématopoïèse, CHU Pontchaillou, Rennes, France
| | - Jacques Cadranel
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de référence constitutif des maladies pulmonaires rares, Hôpital Tenon, APHP, Paris, France
| | - Leonidas Chavez
- Service de Pneumologie, Centre de compétences des maladies pulmonaires rares, CHU Grenoble-Alpes, Grenoble, France
| | - Vincent Cottin
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre national de référence des maladies pulmonaires rares, Hôpital Louis Pradel, Université Claude Bernard Lyon 1, Lyon, France
| | - Emmanuel Gomez
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de compétences des maladies pulmonaires rares CHRU Nancy, Nancy, France
| | - Sylvain Marchand-Adam
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de compétences des maladies pulmonaires raresCHRU de Tours, Tours, France
| | - Sylvie Leroy
- OrphaLung, Lyon, France.,FHU Oncoage, Service de Pneumologie, Centre de compétence des maladies pulmonaires rares, Université Côte d'Azur, CHU de Nice, Nice, France
| | - Jean-Marc Naccache
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de référence constitutif des maladies pulmonaires rares, Hôpital Tenon, APHP, Paris, France
| | - Hilario Nunes
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de référence constitutif des maladies pulmonaires rares, Hôpital Avicenne, APHP, Bobigny, France
| | - Martine Reynaud-Gaubert
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de compétence des maladies pulmonaires rares, Hôpital Nord, Marseille, France
| | - Laurent Savale
- Service de Pneumologie, Centre de référence de l'hypertension pulmonaire, Hôpital Bicêtre, APHP, Le Kremlin Bicêtre, France
| | - Abdellatif Tazi
- Service de Pneumologie, Hôpital Saint-Louis, APHP, Paris, France
| | - Lidwine Wemeau-Stervinou
- OrphaLung, Lyon, France.,Service de Pneumologie, Centre de référence constitutif des maladies pulmonaires rares, CHRU de Lille, Lille, France
| | | | - Bruno Crestani
- Service de Pneumologie A, DHU FIRE, centre de référence constitutif des maladies pulmonaires rares, Hôpital Bichat, APHP, 46 rue Henri Huchard 75877 Paris CEDEX, 18, Paris, France.,OrphaLung, Lyon, France.,INSERM, Unité 1152, Université Paris Diderot, Paris, France
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9
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Park S, Kim S, Kim MJ, Hong Y, Lee AY, Lee H, Tran Q, Kim M, Cho H, Park J, Kim KP, Park J, Cho MH. GOLGA2 loss causes fibrosis with autophagy in the mouse lung and liver. Biochem Biophys Res Commun 2017; 495:594-600. [PMID: 29128360 DOI: 10.1016/j.bbrc.2017.11.049] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 01/20/2023]
Abstract
Autophagy is a biological recycling process via the self-digestion of organelles, proteins, and lipids for energy-consuming differentiation and homeostasis. The Golgi serves as a donor of the double-membraned phagophore for autophagosome assembly. In addition, recent studies have demonstrated that pulmonary and hepatic fibrosis is accompanied by autophagy. However, the relationships among Golgi function, autophagy, and fibrosis are unclear. Here, we show that the deletion of GOLGA2, encoding a cis-Golgi protein, induces autophagy with Golgi disruption. The induction of autophagy leads to fibrosis along with the reduction of subcellular lipid storage (lipid droplets and lamellar bodies) by autophagy in the lung and liver. GOLGA2 knockout mice clearly demonstrated fibrosis features such as autophagy-activated cells, densely packed hepatocytes, increase of alveolar macrophages, and decrease of alveolar surfactant lipids (dipalmitoylphosphatidylcholine). Therefore, we confirmed the associations among Golgi function, fibrosis, and autophagy. Moreover, GOLGA2 knockout mice may be a potentially valuable animal model for studying autophagy-induced fibrosis.
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Affiliation(s)
- Sungjin Park
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Sanghwa Kim
- Division of Basic Radiation Bioscience, Korea Institute of Radiological & Medical Science, Seoul, Republic of Korea
| | - Min Jung Kim
- Department of Applied Chemistry, College of Applied Science, Kyung Hee University, Yongin 17104, Republic of Korea
| | - Youngeun Hong
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Ah Young Lee
- Laboratory of Toxicology, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyunji Lee
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Quangdon Tran
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Minhee Kim
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Hyeonjeong Cho
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Jisoo Park
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea
| | - Kwang Pyo Kim
- Department of Applied Chemistry, College of Applied Science, Kyung Hee University, Yongin 17104, Republic of Korea.
| | - Jongsun Park
- Department of Pharmacology and Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon 35015, Republic of Korea.
| | - Myung-Haing Cho
- Laboratory of Toxicology, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea; Graduate School of Convergence Science and Technology, Seoul National University, Suwon 16229, Republic of Korea; Graduate Group of Tumor Biology, Seoul National University, Seoul 08826, Republic of Korea; Advanced Institute of Convergence Technology, Seoul National University, Suwon 16229, Republic of Korea; Institute of GreenBio Science Technology, Seoul National University, Pyeongchang 25354, Republic of Korea.
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10
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Abstract
Macrophages are critical to organ structure and function in health and disease. To determine mechanisms by which granulocyte/macrophage-colony stimulating factor (GM-CSF) signaling normally maintains surfactant homeostasis and how its disruption causes pulmonary alveolar proteinosis (PAP), we evaluated lipid composition in alveolar macrophages and lung surfactant, macrophage-mediated surfactant clearance kinetics/dynamics, and cholesterol-targeted pharmacotherapy of PAP in vitro and in vivo. Without GM-CSF signaling, surfactant-exposed macrophages massively accumulated cholesterol ester-rich lipid-droplets and surfactant had an increased proportion of cholesterol. GM-CSF regulated cholesterol clearance in macrophages in constitutive, dose-dependent, and reversible fashion but did not affect phospholipid clearance. PPARγ-agonist therapy increased cholesterol clearance in macrophages and reduced disease severity in PAP mice. Results demonstrate that GM-CSF is required for cholesterol clearance in macrophages, identify reduced cholesterol clearance as the primary macrophage defect driving PAP pathogenesis, and support the feasibility of translating pioglitazone as a novel pharmacotherapy of PAP.
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11
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de Aguiar Vallim TQ, Lee E, Merriott DJ, Goulbourne CN, Cheng J, Cheng A, Gonen A, Allen RM, Palladino END, Ford DA, Wang T, Baldán Á, Tarling EJ. ABCG1 regulates pulmonary surfactant metabolism in mice and men. J Lipid Res 2017; 58:941-954. [PMID: 28264879 DOI: 10.1194/jlr.m075101] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/03/2017] [Indexed: 12/27/2022] Open
Abstract
Idiopathic pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by accumulation of surfactant. Surfactant synthesis and secretion are restricted to epithelial type 2 (T2) pneumocytes (also called T2 cells). Clearance of surfactant is dependent upon T2 cells and macrophages. ABCG1 is highly expressed in both T2 cells and macrophages. ABCG1-deficient mice accumulate surfactant, lamellar body-loaded T2 cells, lipid-loaded macrophages, B-1 lymphocytes, and immunoglobulins, clearly demonstrating that ABCG1 has a critical role in pulmonary homeostasis. We identify a variant in the ABCG1 promoter in patients with PAP that results in impaired activation of ABCG1 by the liver X receptor α, suggesting that ABCG1 basal expression and/or induction in response to sterol/lipid loading is essential for normal lung function. We generated mice lacking ABCG1 specifically in either T2 cells or macrophages to determine the relative contribution of these cell types on surfactant lipid homeostasis. These results establish a critical role for T2 cell ABCG1 in controlling surfactant and overall lipid homeostasis in the lung and in the pathogenesis of human lung disease.
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Affiliation(s)
- Thomas Q de Aguiar Vallim
- Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095.,Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095.,Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095.,Johnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095
| | - Elinor Lee
- Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095.,Division of Pulmonary and Critical Care Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - David J Merriott
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | | | - Joan Cheng
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Angela Cheng
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Ayelet Gonen
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Ryan M Allen
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO 63104
| | - Elisa N D Palladino
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO 63104.,Center for Cardiovascular Research, School of Medicine, Saint Louis University, St. Louis, MO 63104
| | - David A Ford
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO 63104.,Center for Cardiovascular Research, School of Medicine, Saint Louis University, St. Louis, MO 63104
| | - Tisha Wang
- Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095.,Division of Pulmonary and Critical Care Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Ángel Baldán
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO 63104
| | - Elizabeth J Tarling
- Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095 .,Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095.,Johnson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095
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12
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Ledford JG, Addison KJ, Foster MW, Que LG. Eosinophil-associated lung diseases. A cry for surfactant proteins A and D help? Am J Respir Cell Mol Biol 2015; 51:604-14. [PMID: 24960334 DOI: 10.1165/rcmb.2014-0095tr] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Surfactant proteins (SP)-A and SP-D (SP-A/-D) play important roles in numerous eosinophil-dominated diseases, including asthma, allergic bronchopulmonary aspergillosis, and allergic rhinitis. In these settings, SP-A/-D have been shown to modulate eosinophil chemotaxis, inhibit eosinophil mediator release, and mediate macrophage clearance of apoptotic eosinophils. Dysregulation of SP-A/-D function in eosinophil-dominated diseases is also not uncommon. Alterations in serum SP-A/-D levels are associated with disease severity in allergic rhinitis and chronic obstructive pulmonary disease. Furthermore, oligimerization of SP-A/-D, necessary for their proper function, can be perturbed by reactive nitrogen species, which are increased in eosinophilic disease. In this review, we highlight the associations of eosinophilic lung diseases with SP-A and SP-D levels and functions.
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Affiliation(s)
- Julie G Ledford
- 1 Department of Medicine, Division of Pulmonary, Allergy and Critical Care, and
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13
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Mukherjee D, Botelho D, Gow AJ, Zhang J, Georgopoulos PG. Computational multiscale toxicodynamic modeling of silver and carbon nanoparticle effects on mouse lung function. PLoS One 2013; 8:e80917. [PMID: 24312506 PMCID: PMC3849047 DOI: 10.1371/journal.pone.0080917] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/17/2013] [Indexed: 11/18/2022] Open
Abstract
A computational, multiscale toxicodynamic model has been developed to quantify and predict pulmonary effects due to uptake of engineered nanomaterials (ENMs) in mice. The model consists of a collection of coupled toxicodynamic modules, that were independently developed and tested using information obtained from the literature. The modules were developed to describe the dynamics of tissue with explicit focus on the cells and the surfactant chemicals that regulate the process of breathing, as well as the response of the pulmonary system to xenobiotics. Alveolar type I and type II cells, and alveolar macrophages were included in the model, along with surfactant phospholipids and surfactant proteins, to account for processes occurring at multiple biological scales, coupling cellular and surfactant dynamics affected by nanoparticle exposure, and linking the effects to tissue-level lung function changes. Nanoparticle properties such as size, surface chemistry, and zeta potential were explicitly considered in modeling the interactions of these particles with biological media. The model predictions were compared with in vivo lung function response measurements in mice and analysis of mice lung lavage fluid following exposures to silver and carbon nanoparticles. The predictions were found to follow the trends of observed changes in mouse surfactant composition over 7 days post dosing, and are in good agreement with the observed changes in mouse lung function over the same period of time.
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Affiliation(s)
- Dwaipayan Mukherjee
- Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, United States of America
- Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey, United States of America
| | - Danielle Botelho
- Department of Pharmacology and Toxicology, Rutgers University, Piscataway, New Jersey, United States of America
| | - Andrew J. Gow
- Department of Pharmacology and Toxicology, Rutgers University, Piscataway, New Jersey, United States of America
| | - Junfeng Zhang
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, California, United States of America
| | - Panos G. Georgopoulos
- Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, United States of America
- Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey, United States of America
- * E-mail:
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14
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Fukuzawa T, Ishida J, Kato A, Ichinose T, Ariestanti DM, Takahashi T, Ito K, Abe J, Suzuki T, Wakana S, Fukamizu A, Nakamura N, Hirose S. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D. PLoS One 2013; 8:e69451. [PMID: 23922714 PMCID: PMC3726689 DOI: 10.1371/journal.pone.0069451] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/08/2013] [Indexed: 12/21/2022] Open
Abstract
Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta+/+ and Ig-Hepta−/− mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i) balanced synthesis of surfactant lipids and proteins and (ii) surfactant secretion, and (iii) a stimulating effect on recycling (uptake) in response to elevated levels of Sp-D in alveolar space.
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MESH Headings
- 1,2-Dipalmitoylphosphatidylcholine/metabolism
- Animals
- Cell Count
- Gene Expression Regulation, Developmental
- Gene Targeting
- Hypertrophy
- Immunohistochemistry
- In Situ Hybridization
- Ligands
- Lung/abnormalities
- Lung/metabolism
- Lung/pathology
- Macrophages, Alveolar/metabolism
- Macrophages, Alveolar/pathology
- Matrix Metalloproteinase 12/metabolism
- Mice
- Mice, Transgenic
- Models, Biological
- Protein Binding
- Protein Biosynthesis
- Protein Structure, Tertiary
- Pulmonary Surfactant-Associated Protein D/metabolism
- Pulmonary Surfactants/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/deficiency
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- beta-Galactosidase/metabolism
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Affiliation(s)
- Taku Fukuzawa
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | - Junji Ishida
- Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Japan
| | - Akira Kato
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | - Taro Ichinose
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | | | - Tomoya Takahashi
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | - Kunitoshi Ito
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | - Jumpei Abe
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | - Tomohiro Suzuki
- Technology and Development Team for Mouse Phenotype Analysis, RIKEN BioResource Center, Tsukuba, Japan
| | - Shigeharu Wakana
- Technology and Development Team for Mouse Phenotype Analysis, RIKEN BioResource Center, Tsukuba, Japan
| | - Akiyoshi Fukamizu
- Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Japan
| | - Nobuhiro Nakamura
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
| | - Shigehisa Hirose
- Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan
- Faculty of Biomedical Engineering, Toin University of Yokohama, Yokohama, Japan
- * E-mail:
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15
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Roszell BR, Tao JQ, Yu KJ, Gao L, Huang S, Ning Y, Feinstein SI, Vite CH, Bates SR. Pulmonary abnormalities in animal models due to Niemann-Pick type C1 (NPC1) or C2 (NPC2) disease. PLoS One 2013; 8:e67084. [PMID: 23843985 PMCID: PMC3699545 DOI: 10.1371/journal.pone.0067084] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 05/14/2013] [Indexed: 11/18/2022] Open
Abstract
Niemann-Pick C (NPC) disease is due to loss of NPC1 or NPC2 protein function that is required for unesterified cholesterol transport from the endosomal/lysosomal compartment. Though lung involvement is a recognized characteristic of Niemann-Pick type C disease, the pathological features are not well understood. We investigated components of the surfactant system in both NPC1 mutant mice and felines and in NPC2 mutant mice near the end of their expected life span. Histological analysis of the NPC mutant mice demonstrated thickened septae and foamy macrophages/leukocytes. At the level of electron microscopy, NPC1-mutant type II cells had uncharacteristically larger lamellar bodies (LB, mean area 2-fold larger), while NPC2-mutant cells had predominantly smaller lamellar bodies (mean area 50% of normal) than wild type. Bronchoalveolar lavage from NPC1 and NPC2 mutant mice had an approx. 4-fold and 2.5-fold enrichment in phospholipid, respectively, and an approx. 9-fold and 35-fold enrichment in cholesterol, consistent with alveolar lipidosis. Phospholipid and cholesterol also were elevated in type II cell LBs and lung tissue while phospholipid degradation was reduced. Enrichment of surfactant protein-A in the lung and surfactant of the mutant mice was found. Immunocytochemical results showed that cholesterol accumulated in the LBs of the type II cells isolated from the affected mice. Alveolar macrophages from the NPC1 and NPC2 mutant mice were enlarged compared to those from wild type mice and were enriched in phospholipid and cholesterol. Pulmonary features of NPC1 mutant felines reflected the disease described in NPC1 mutant mice. Thus, with the exception of lamellar body size, the lung phenotype seen in the NPC1 and NPC2 mutant mice were similar. The lack of NPC1 and NPC2 proteins resulted in a disruption of the type II cell surfactant system contributing to pulmonary abnormalities.
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Affiliation(s)
- Blair R. Roszell
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jian-Qin Tao
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kevin J. Yu
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ling Gao
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Shaohui Huang
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yue Ning
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sheldon I. Feinstein
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Charles H. Vite
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sandra R. Bates
- Institute for Environmental Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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16
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Sever-Chroneos Z, Tvinnereim A, Hunter RL, Chroneos ZC. Prolonged survival of scavenger receptor class A-deficient mice from pulmonary Mycobacterium tuberculosis infection. Tuberculosis (Edinb) 2011; 91 Suppl 1:S69-74. [PMID: 22088322 DOI: 10.1016/j.tube.2011.10.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The present study tested the hypothesis that the scavenger receptor SR-A modulates granuloma formation in response to pulmonary infection with Mycobacterium tuberculosis (MTB). To test this hypothesis, we monitored survival and histopathology in WT and SR-A-deficient mice following aerosol infection with MTB Rv. SR-A-deficient (SR-A-/-) mice infected with MTB survived significantly longer than WT mice; the mean survival of SR-A-/- mice exceeded 430 days compared to 230 days for WT mice. Early granuloma formation was not impaired in SR-A-/- mice. The extended survival of SR-A-/- mice was associated with 13- and 3-fold higher number of CD4+ lymphocytes and antigen presenting cells in SR-A-/- lungs compared to WT mice 280 after infection. The histopathology of chronically infected SR-A-/- lungs, however, was marked by abundant cholesterol clefts in parenchymal lesions containing infection in multinucleated giant cells. The present study indicates SR-A as a candidate gene of the innate immune system influencing the chronic phase of M. tuberculosis infection.
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Affiliation(s)
- Zvjezdana Sever-Chroneos
- University of Texas Health Science Center at Tyler, The Center for Biomedical Research, 11937 US Highway 271, Tyler, TX 75708-3154, United States.
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17
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Toxic alveolitis after inhalation of a water repellent. Int J Occup Med Environ Health 2011; 24:409-13. [PMID: 22002324 DOI: 10.2478/s13382-011-0038-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/22/2011] [Indexed: 11/20/2022] Open
Abstract
Inhalation of fluorocarbon polymers can cause pulmonary toxicity. Although multiple cases of lung injury have been reported, cellular characterization of the associated alveolitis occurring acutely after inhalation is limited. We report the case of a previously healthy woman who presented at our Emergency Department with an acute pneumonitis following inhalation of a fluorocarbon polymer-based rain-proofing spray. Bronchoalveolar lavage (BAL) performed shortly after the presentation showed an elevated total cell count, with a high proportion of neutrophils (58%) and eosinophils (9%). In addition, a lipid stain (Oil-Red-O-stain) showed a high level of lipid laden macrophages, a marker that could reflect a direct toxic effect of the spray on alveolar cells. The patient made a full recovery after four days of in-hospital observation with supportive care.
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18
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Surfactant protein C is an essential constituent for mucosal adjuvanticity of Surfacten, acting as an antigen delivery vehicle and inducing both local and systemic immunity. Vaccine 2011; 29:5368-78. [PMID: 21669246 DOI: 10.1016/j.vaccine.2011.05.090] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 04/09/2011] [Accepted: 05/21/2011] [Indexed: 11/21/2022]
Abstract
We have reported that Surfacten(®) (St), a bovine pulmonary surfactant free of antigenic c-type lectins, is a useful mucosal adjuvant for nasal vaccination. To prepare ample supplies a synthetic adjuvant that mimics St, we analyzed essential constituents of St for mucosal adjuvanticity. Intranasal inoculation of influenza virus hemagglutinin (HA) vaccine combined with St free of surfactant protein (SP)-C resulted in failure of HA vaccine delivery to dendritic cells and loss of local and systemic immune responses. Naïve bovine SP-C, synthetic human or bovine SP-C peptide reconstituted with three major St lipids restored delivery activity and local and systemic immune responses to levels similar to those of St and provided almost complete protection against lethal doses of influenza virus challenge in mice. The delivery of fluoresceinated HA vaccine to cultured dendritic cells was significantly enhanced by co-administration of St or synthetic adjuvant, and moderately stimulated the expression of MHC class II and CD86. In addition, both St and synthetic adjuvant markedly sustained HA vaccine and achieved a wide antigen distribution in murine nasal cavity. These results suggest that synthetic mucosal adjuvant reconstituted with SP-C peptide and major St lipids is useful for ample supply of the potent mucosal adjuvant as an antigen delivery vehicle for intranasal vaccination.
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19
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Chroneos ZC, Sever-Chroneos Z, Shepherd VL. Pulmonary surfactant: an immunological perspective. Cell Physiol Biochem 2009; 25:13-26. [PMID: 20054141 DOI: 10.1159/000272047] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2009] [Indexed: 11/19/2022] Open
Abstract
Pulmonary surfactant has two crucial roles in respiratory function; first, as a biophysical entity it reduces surface tension at the air water interface, facilitating gas exchange and alveolar stability during breathing, and, second, as an innate component of the lung's immune system it helps maintain sterility and balance immune reactions in the distal airways. Pulmonary surfactant consists of 90% lipids and 10% protein. There are four surfactant proteins named SP-A, SP-B, SP-C, and SP-D; their distinct interactions with surfactant phospholipids are necessary for the ultra-structural organization, stability, metabolism, and lowering of surface tension. In addition, SP-A and SP-D bind pathogens, inflict damage to microbial membranes, and regulate microbial phagocytosis and activation or deactivation of inflammatory responses by alveolar macrophages. SP-A and SP-D, also known as pulmonary collectins, mediate microbial phagocytosis via SP-A and SP-D receptors and the coordinated induction of other innate receptors. Several receptors (SP-R210, CD91/calreticulin, SIRPalpha, and toll-like receptors) mediate the immunological functions of SP-A and SP-D. However, accumulating evidence indicate that SP-B and SP-C and one or more lipid constituents of surfactant share similar immuno-regulatory properties as SP-A and SP-D. The present review discusses current knowledge on the interaction of surfactant with lung innate host defense.
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Affiliation(s)
- Zissis C Chroneos
- The Center of Biomedical Research, University of Texas Health Science Center at Tyler, Tyler, TX 75708-3154, USA.
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20
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Moulakakis C, Stamme C. Role of clathrin-mediated endocytosis of surfactant protein A by alveolar macrophages in intracellular signaling. Am J Physiol Lung Cell Mol Physiol 2009; 296:L430-41. [PMID: 19136579 DOI: 10.1152/ajplung.90458.2008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We recently provided evidence that anti-inflammatory macrophage activation, i.e., the inhibition of constitutive and signal-induced NF-kappaB activity by the pulmonary collectin surfactant protein (SP)-A, critically involves a promoted stabilization of IkappaB-alpha, the predominant inhibitor of NF-kappaB, via posttranscriptional mechanisms comprising the activation of atypical (a)PKCzeta. SP-A uptake and degradation by alveolar macrophages (AMphi) occur in a receptor-mediated, clathrin-dependent manner. However, a mutual link between endocytosis of and signaling by SP-A remains elusive. The aim of this study was to investigate whether clathrin-mediated endocytosis (CME) of SP-A by AMphi is a prerequisite for its modulation of the IkappaB-alpha/NF-kappaB pathway. The inhibition of clathrin-coated pit (CCP) formation and clathrin-coated vesicle (CCV) formation/budding abrogates SP-A-mediated IkappaB-alpha stabilization and SP-A-mediated inhibition of LPS-induced NF-kappaB activation in freshly isolated rat AMphi, as determined by Western analysis, fluorescence-activated cell sorting, confocal microscopy, and EMSA. Actin depolymerization and inhibition of CCP formation further abolished SP-A-mediated inhibition of LPS-induced TNF-alpha release, as determined by ELISA. In addition, SP-A-induced atypical PKCzeta activation was abolished by pretreatment of AMphi with CCV inhibitors as determined by in vitro immunocomplex kinase assay. Although CME is classically considered as a means to terminate signaling, our results demonstrate that SP-A uptake via CME by AMphi has to precede the initiation of SP-A signaling.
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Affiliation(s)
- Christina Moulakakis
- Department of Clinical Medicine, Division of Cellular Pneumology, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
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21
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Szeliga J, Daniel DS, Yang CH, Sever-Chroneos Z, Jagannath C, Chroneos ZC. Granulocyte-macrophage colony stimulating factor-mediated innate responses in tuberculosis. Tuberculosis (Edinb) 2007; 88:7-20. [PMID: 17928269 DOI: 10.1016/j.tube.2007.08.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 07/20/2007] [Accepted: 08/27/2007] [Indexed: 01/01/2023]
Abstract
The mechanisms by which GM-CSF mediates bacterial clearance and inflammation during mycobacterial infection are poorly understood. The objective of this work was to determine how GM-CSF alters pulmonary mycobacterial infection in vivo. Differences in GM-CSF levels in the lungs of normal mice (GM(+/+)), transgenic GM-CSF-deficient (GM-CSF(-/-)), and transgenic mice with high GM-CSF expression only in lung epithelial cells (SP-C-GM-CSF(+/+)/GM(-/-)) did not affect pulmonary infection rates caused by either the attenuated Mycobacterium bovis BCG or the virulent Mycobacterium tuberculosis H37Rv. However, in contrast to findings with BCG, all GM-CSF(-/-) and SP-C-GM-CSF(+/+)/GM(-/-) mice succumbed prematurely to virulent H37Rv. Granuloma formation was impaired in both GM-CSF(-/-) and SP-C-GM-CSF(+/+)/GM(-/-) mice regardless of mycobacterial virulence. However, H37Rv-infected GM-CSF(-/-) mice suffered broncho-alveolar destruction, edema, and necrosis while only short-lived granulomas were observed in SP-C-GM-CSF(+/+)/GM(-/-) mice. Bone marrow-derived macrophages, but not dendritic cells of SP-C-GM-CSF(+/+)/GM(-/-) mice, were hypo-responsive to mycobacterial infection. Surfactant protein levels were differentially influenced by BCG and H37Rv. We conclude that GM-CSF has an essential protective role first in preserving alveolar structure and second in regulating macrophages and dendritic cells to facilitate containment of virulent mycobacteria in pulmonary granulomas. However, precise regulation of lung GM-CSF is vital to effective control of M. tuberculosis.
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Affiliation(s)
- Jacek Szeliga
- Center of Biomedical Research, University of Texas Health Center at Tyler, Tyler, TX 75708-3154, USA
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22
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Lasbury ME, Durant PJ, Wang SH, Zhang C, Liao CP, Tschang D, Lee CH. Alterations in surfactant protein A form and clearance during Pneumocystis pneumonia. J Eukaryot Microbiol 2007; 53 Suppl 1:S119-21. [PMID: 17169024 DOI: 10.1111/j.1550-7408.2006.00197.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mark E Lasbury
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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23
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Forbes A, Pickell M, Foroughian M, Yao LJ, Lewis J, Veldhuizen R. Alveolar macrophage depletion is associated with increased surfactant pool sizes in adult rats. J Appl Physiol (1985) 2007; 103:637-45. [PMID: 17446406 DOI: 10.1152/japplphysiol.00995.2006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary surfactant is a lipid-protein material that is essential for normal lung function. Maintaining normal and consistent alveolar amounts of surfactant is in part dependent on clearance of surfactant by alveolar macrophages (AM). The present study utilized a rat model of AM depletion to determine the impact on surfactant pool sizes and function over time. Male Sprague-Dawley rats were anesthetized and intratracheally instilled with PBS-liposomes (PBS-L) or dichloromethylene diphosphonic acid (DMDP) containing liposomes (DMDP-L) and were killed at various time points up to 21 days for compliance measurements, AM cell counts, and surfactant analysis. AM numbers were significantly decreased 1, 2, and 3 days after instillation in DMDP-L vs. PBS-L, with 72% depletion at 3 days. AM numbers returned to normal levels by 5 days. In DMDP-L rats, there was a rapid increase in surfactant-phospholipid pools, showing a ninefold increase in the amount of surfactant in the lavage 3 days after liposome instillation. Surfactant accumulation progressed up to 7 days, with pools normalizing by 21 days. The increase in surfactant was due to increases in both subfractions of surfactant, the large aggregates (LA) and small aggregates. Surfactant protein A levels, relative to LA phospholipids, were not increased. There was a decreased extent of surfactant conversion in vitro for LA from DMDP-L rats compared with controls. It is concluded that the procedure of AM depletion significantly affects surfactant metabolism. The increased endogenous surfactant must be considered when utilizing the AM depletion model to study the role of these cells during lung insults.
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Affiliation(s)
- Amy Forbes
- Lawson Health Research Institute, Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
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24
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Cogo PE, Toffolo GM, Ori C, Vianello A, Chierici M, Gucciardi A, Cobelli C, Baritussio A, Carnielli VP. Surfactant disaturated-phosphatidylcholine kinetics in acute respiratory distress syndrome by stable isotopes and a two compartment model. Respir Res 2007; 8:13. [PMID: 17313681 PMCID: PMC1819376 DOI: 10.1186/1465-9921-8-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Accepted: 02/21/2007] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND In patients with acute respiratory distress syndrome (ARDS), it is well known that only part of the lungs is aerated and surfactant function is impaired, but the extent of lung damage and changes in surfactant turnover remain unclear. The objective of the study was to evaluate surfactant disaturated-phosphatidylcholine turnover in patients with ARDS using stable isotopes. METHODS We studied 12 patients with ARDS and 7 subjects with normal lungs. After the tracheal instillation of a trace dose of 13C-dipalmitoyl-phosphatidylcholine, we measured the 13C enrichment over time of palmitate residues of disaturated-phosphatidylcholine isolated from tracheal aspirates. Data were interpreted using a model with two compartments, alveoli and lung tissue, and kinetic parameters were derived assuming that, in controls, alveolar macrophages may degrade between 5 and 50% of disaturated-phosphatidylcholine, the rest being lost from tissue. In ARDS we assumed that 5-100% of disaturated-phosphatidylcholine is degraded in the alveolar space, due to release of hydrolytic enzymes. Some of the kinetic parameters were uniquely determined, while others were identified as lower and upper bounds. RESULTS In ARDS, the alveolar pool of disaturated-phosphatidylcholine was significantly lower than in controls (0.16 +/- 0.04 vs. 1.31 +/- 0.40 mg/kg, p < 0.05). Fluxes between tissue and alveoli and de novo synthesis of disaturated-phosphatidylcholine were also significantly lower, while mean resident time in lung tissue was significantly higher in ARDS than in controls. Recycling was 16.2 +/- 3.5 in ARDS and 31.9 +/- 7.3 in controls (p = 0.08). CONCLUSION In ARDS the alveolar pool of surfactant is reduced and disaturated-phosphatidylcholine turnover is altered.
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Affiliation(s)
- Paola E Cogo
- Department of Pediatrics, University of Padova, Padova, Italy
| | | | - Carlo Ori
- Department of Pharmacology, Anaesthesia and Critical Care, University of Padova, Padova, Italy
| | | | - Marco Chierici
- Department of Information Engineering, University of Padova, Italy
| | | | - Claudio Cobelli
- Department of Information Engineering, University of Padova, Italy
| | - Aldo Baritussio
- Department of Medical and Surgical Sciences, University of Padova, Padova, Italy
| | - Virgilio P Carnielli
- Neonatal Division, Salesi Children's Hospital, Ancona, Italy
- Nutrition Unit, Institute of Child Health and Great Ormond Street Hospital, London, UK
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25
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Abstract
Alveolar pulmonary surfactant is a complex of macromolecular aggregates composed of phospholipids and surfactant proteins (SP) that is essential for maintenance of normal lung function. The importance of surfactant homeostasis is recognized in the patients and the animal models with pulmonary disease, although the mechanisms of surfactant homeostasis are not fully understood. In this review the author will discuss: (i) the mechanisms of the surfactant catabolism by macrophage and type II cells; and (ii) the important role of SP-D on ultrastructure of surfactant that affects uptake by type II cells.
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Affiliation(s)
- Machiko Ikegami
- Cincinnati Children's Hospital, Division of Pulmonary Biology, University of Cincinnati, Cincinnati, OH 45229, USA.
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Akei H, Whitsett JA, Buroker M, Ninomiya T, Tatsumi H, Weaver TE, Ikegami M. Surface tension influences cell shape and phagocytosis in alveolar macrophages. Am J Physiol Lung Cell Mol Physiol 2006; 291:L572-9. [PMID: 16632521 DOI: 10.1152/ajplung.00060.2006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The effect of surface tension on alveolar macrophage shape and phagocytosis was assessed in vivo and in vitro. Surface tension was regulated in vivo by conditionally expressing surfactant protein (SP)-B in Sftpb-/- mice. Increased surface tension and respiratory distress were produced by depletion of SP-B and were readily reversed by repletion of SP-B in vivo. Electron microscopy was used to demonstrate that alveolar macrophages were usually located beneath the surfactant film on the alveolar surfaces. Reduction of SP-B increased surface tension and resulted in flattening of alveolar macrophages on epithelial surfaces in vivo. Phagocytosis of intratracheally injected fluorescent microbeads by alveolar macrophages was decreased during SP-B deficiency and was restored by repletion of SP-B in vivo. Incubation of MH-S cells, a mouse macrophage cell line, with inactive surfactant caused cell flattening and decreased phagocytosis in vitro, findings that were reversed by the addition of sheep surfactant or phospholipid containing SP-B. SP-B controls surface tension by forming a surfactant phospholipid film that regulates shape and nonspecific phagocytic activity of alveolar macrophages on the alveolar surface.
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Affiliation(s)
- Hiroko Akei
- Cincinnati Children's Hospital, Division of Pulmonary Biology, University of Cincinnati, OH 45229-3039, USA
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27
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Jain D, Dodia C, Fisher AB, Bates SR. Pathways for clearance of surfactant protein A from the lung. Am J Physiol Lung Cell Mol Physiol 2005; 289:L1011-8. [PMID: 16006481 DOI: 10.1152/ajplung.00250.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Uptake and degradation of (125)I-surfactant protein A (SP-A) over a 1-h period was studied in alveolar cells in culture and in isolated perfused lungs to elucidate the mechanism for clearance of the protein from the alveolar space. Specific inhibitors of clathrin- and actin-dependent endocytosis were utilized. In type II cells, uptake of SP-A, compared with controls, was decreased by 60% on incubation with clathrin inhibitors (amantadine and phenylarsine oxide) or with the actin inhibitor cytochalasin D. All agents reduced SP-A metabolism by alveolar macrophages. Untreated rat isolated perfused lungs internalized 36% of instilled SP-A, and 56% of the incorporated SP-A was degraded. Inhibitors of clathrin and actin significantly reduced SP-A uptake by approximately 54%, whereas cytochalasin D inhibited SP-A degradation. Coincubation of agents did not produce an additive effect on uptake of SP-A by cultured pneumocytes or isolated perfused lungs, indicating that all agents affected the same pathway. Thus SP-A clears the lung via a clathrin-mediated pathway that requires the polymerization of actin.
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Affiliation(s)
- Deepika Jain
- Institute for Environmental Medicine, University of Pennsylvania School of Medicine, 1 John Morgan Bldg., 3620 Hamilton Walk, Philadelphia, PA 19104-6068, USA
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Surfactant metabolism: factors affecting lipid uptake in vivo and in vitro. ANAESTHESIA, PAIN, INTENSIVE CARE AND EMERGENCY MEDICINE — A.P.I.C.E. 2005. [PMCID: PMC7122009 DOI: 10.1007/88-470-0351-2_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ikegami M, Na CL, Korfhagen TR, Whitsett JA. Surfactant protein D influences surfactant ultrastructure and uptake by alveolar type II cells. Am J Physiol Lung Cell Mol Physiol 2004; 288:L552-61. [PMID: 15579631 DOI: 10.1152/ajplung.00142.2004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surfactant protein D (SP-D) is a member of the collectin family of the innate host defense proteins. In the lung, SP-D is expressed primarily by type II cells. Gene-targeted SP-D-deficient [SP-D(-/-)] mice have three- to fivefold higher surfactant lipid pool sizes. However, surfactant synthesis and secretion by type II cells and catabolism by alveolar macrophages are normal in SP-D(-/-) mice. Therefore, we hypothesized that SP-D might regulate surfactant homeostasis by influencing surfactant structure, thereby altering its uptake by type II cells. Large (LA) and small aggregate (SA) surfactant were isolated from bronchoalveolar lavage fluid (BALF) from SP-D(-/-), wild-type [SP-D(+/+)], and transgenic mice in which SP-D was expressed under conditional control of doxycycline in alveolar type II cells. Uptake of both LA and SA isolated from SP-D(-/-) mice by normal type II cells was decreased. Abnormally dense lipid forms were observed by electron microscopy of LA from SP-D(-/-) mice. SA from SP-D(-/-) mice consisted of atypical multilamellated small vesicles. Abnormalities in surfactant uptake by type II cells and in surfactant ultrastructure were corrected by conditional expression of SP-D in vivo. Preincubation of BALF from SP-D(-/-) mice with SP-D changed surfactant ultrastructure to be similar to that of SP-D(+/+) mice in vitro. The rapid changes in surfactant structure, increased uptake by type II cells, and decreased pool sizes normally occurring in the postnatal period were not seen in SP-D(-/-) mice. SP-D regulates uptake and catabolism by type II cells and influences the ultrastructure of surfactant in the alveolus.
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Affiliation(s)
- Machiko Ikegami
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, USA.
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30
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Abstract
Pulmonary alveolar proteinosis (PAP) has been recognized for almost half a century. At least three separate pathophysiologic mechanisms may lead to the characteristic feature of PAP: the excessive accumulation of surfactant lipoprotein in pulmonary alveoli, with associated disturbance of pulmonary gas exchange. The prognosis for adult patients with PAP varies, but disease-specific survival rate exceeds 80% at 5 years. The survival rates for adult PAP patients seem to have increased progressively in the four decades since the initial clinical description of this condition. The last decade has brought new advances in laboratory and clinical research that are lifting a veil not only on PAP but also on general aspects of pulmonary surfactant biology and innate immune defense.
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Affiliation(s)
- Jeffrey J Presneill
- Intensive Care Unit, Royal Melbourne Hospital, Grattan Street, Parkville 3050, Victoria, Australia
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31
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Malloy JL, Veldhuizen RAW, Thibodeaux BA, O'Callaghan RJ, Wright JR. Pseudomonas aeruginosa protease IV degrades surfactant proteins and inhibits surfactant host defense and biophysical functions. Am J Physiol Lung Cell Mol Physiol 2004; 288:L409-18. [PMID: 15516485 DOI: 10.1152/ajplung.00322.2004] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary surfactant has two distinct functions within the lung: reduction of surface tension at the air-liquid interface and participation in innate host defense. Both functions are dependent on surfactant-associated proteins. Pseudomonas aeruginosa is primarily responsible for respiratory dysfunction and death in cystic fibrosis patients and is also a leading pathogen in nosocomial pneumonia. P. aeruginosa secretes a number of proteases that contribute to its virulence. We hypothesized that P. aeruginosa protease IV degrades surfactant proteins and results in a reduction in pulmonary surfactant host defense and biophysical functions. Protease IV was isolated from cultured supernatant of P. aeruginosa by gel chromatography. Incubation of cell-free bronchoalveolar lavage fluid with protease IV resulted in degradation of surfactant proteins (SP)-A, -D, and -B. SPs were degraded in a time- and dose-dependent fashion by protease IV, and degradation was inhibited by the trypsin-like serine protease inhibitor Nalpha-p-tosyl-L-lysine-chloromethyl ketone (TLCK). Degradation by protease IV inhibited SP-A- and SP-D-mediated bacterial aggregation and uptake by macrophages. Surfactant treated with protease IV was unable to reduce surface tension as effectively as untreated surfactant, and this effect was inhibited by TLCK. We speculate that protease IV may be an important contributing factor to the development and propagation of acute lung injury associated with P. aeruginosa via loss of surfactant function within the lung.
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Affiliation(s)
- Jaret L Malloy
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
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32
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In vivo clearance of surfactant lipids during acute pulmonary inflammation. Respir Res 2004; 5:8. [PMID: 15357882 PMCID: PMC517704 DOI: 10.1186/1465-9921-5-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2004] [Accepted: 07/23/2004] [Indexed: 11/21/2022] Open
Abstract
Background A decrease in pulmonary surfactant has been suggested to contribute to the lung dysfunction associated with pulmonary inflammation. A number of studies have implicated surfactant clearance as a possible mechanism for altered pool sizes. The objective of the current study was to specifically investigate the mechanisms of surfactant clearance in a rodent model of acute pulmonary inflammation. Methods Inflammation was induced by intrapulmonary instillation of lipopolysaccharide (LPS: 100 μg/kg). Lipid clearance was assessed at 18 and 72 hours post-LPS instillation by intratracheal administration of radiolabel surfactant-like liposomes 2 hours prior to isolation and analysis of inflammatory cells and type II cells. Results At both 18 and 72 hours after LPS instillation there was significantly less radioactivity recovered in the lavage fluid compared to respective control groups (p < 0.05). At both time points, the number of cells recovered by lavage and their associated radioactivity was greater compared to control groups (p < 0.01). There was no difference in recovery of radioactivity by isolated type II cells or other cells obtained from enzymatic digestion of lung tissue. Conclusion These results show that increased clearance of surfactant lipids in our model of acute pulmonary inflammation is primarily due to the inflammatory cells recruited to the airspace and not increased uptake by alveolar type II cells.
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Ikegami M, Dhami R, Schuchman EH. Alveolar lipoproteinosis in an acid sphingomyelinase-deficient mouse model of Niemann-Pick disease. Am J Physiol Lung Cell Mol Physiol 2003; 284:L518-25. [PMID: 12495943 DOI: 10.1152/ajplung.00258.2002] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Types A and B Niemann-Pick disease (NPD) are lipid storage disorders caused by the deficient activity of acid sphingomyelinase (ASM). In humans, NPD is associated with the dysfunction of numerous organs including the lung. Gene targeting of the ASM gene in transgenic mice produced an animal model with features typical of NPD, including pulmonary inflammation. To assess mechanisms by which ASM perturbed lung function, we studied lung morphology, surfactant content, and metabolism in ASM-deficient mice in vivo. Pulmonary inflammation, with increased cellular infiltrates and the accumulation of alveolar material, was associated with alterations in surfactant content. Saturated phosphatidylcholine (SatPC) content was increased twofold, and sphingomyelin content was increased 5.5-fold in lungs of the ASM knockout (ASMKO) mice. Additional sphingomyelin enhanced the sensitivity of surfactant inhibition by plasma proteins. Clearance of SatPC from the lungs of ASMKO mice was decreased. Catabolism of SatPC by alveolar macrophages from the ASMKO mouse was significantly decreased, likely accounting for decreased pulmonary SatPC in vivo. In summary, ASM is required for normal surfactant catabolism by alveolar macrophages in vivo. Alterations in surfactant composition, including increased sphingomyelin content, contributed to the abnormal surfactant function observed in the ASM-deficient mouse.
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Affiliation(s)
- Machiko Ikegami
- Cincinnati Children's Hospital Medical Center, Division of Pulmonary Biology, Cincinnati, Ohio 45229, USA.
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34
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Poelma DLH, Zimmermann LJI, Scholten HH, Lachmann B, van Iwaarden JF. In vivo and in vitro uptake of surfactant lipids by alveolar type II cells and macrophages. Am J Physiol Lung Cell Mol Physiol 2002; 283:L648-54. [PMID: 12169585 DOI: 10.1152/ajplung.00478.2001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The uptake of fluorescent-labeled liposomes (with a surfactant-like composition) by alveolar macrophages and alveolar type II cells was studied using flow cytometry, in vivo by instillation of the labeled liposomes in the trachea of ventilated rats followed by isolation of the alveolar cells and determination of the cell-associated fluorescence, and in vitro by incubation of isolated alveolar cells with the fluorescent liposomes. The results show that the uptake of liposomes by the alveolar cells is time and concentration dependent. In vivo alveolar macrophages internalize more than three times as many liposomes as alveolar type II cells, whereas in vitro, the amount of internalized liposomes by these cells is approximately the same. In vitro, practically all the cells (70-75%) internalize liposomes, whereas in vivo only 30% of the alveolar type II cells ingest liposomes vs. 70% of the alveolar macrophages. These results indicate that in vivo, only a small subpopulation of alveolar type II cells is able to internalize surfactant liposomes.
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Affiliation(s)
- D L H Poelma
- Department of Anesthesiology, Erasmus University Rotterdam, The Netherlands
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35
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Seymour JF, Presneill JJ. Pulmonary alveolar proteinosis: progress in the first 44 years. Am J Respir Crit Care Med 2002; 166:215-35. [PMID: 12119235 DOI: 10.1164/rccm.2109105] [Citation(s) in RCA: 411] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pulmonary alveolar proteinosis is a rare clinical syndrome that was first described in 1958. Subsequently, over 240 case reports and small series have described at least 410 cases in the literature. Characterized by the alveolar accumulation of surfactant components with minimal interstitial inflammation or fibrosis, pulmonary alveolar proteinosis has a variable clinical course ranging from spontaneous resolution to death with pneumonia or respiratory failure. The most effective proven treatment--whole lung lavage--was described soon after the first recognition of this disease. In the last 8 years, there has been rapid progress toward elucidation of the molecular mechanisms underlying both the congenital and acquired forms of pulmonary alveolar proteinosis, following serendipitous discoveries in gene-targeted mice lacking granulocyte-macrophage colony-stimulating factor (GM-CSF). Impairment of surfactant clearance by alveolar macrophages as a result of inhibition of the action of GM-CSF by blocking autoantibodies may underlie many acquired cases, whereas congenital disease is most commonly attributable to mutations in surfactant protein genes but may also be caused by GM-CSF receptor defects. Therapy with GM-CSF has shown promise in approximately half of those acquired cases treated, but it is unsuccessful in congenital forms of the disease, consistent with the known differences in disease pathogenesis.
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Affiliation(s)
- John F Seymour
- Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, and the Intensive Care Unit, The Royal Melbourne Hospital, Parkville, Australia.
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36
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Ikegami M, Hull WM, Yoshida M, Wert SE, Whitsett JA. SP-D and GM-CSF regulate surfactant homeostasis via distinct mechanisms. Am J Physiol Lung Cell Mol Physiol 2001; 281:L697-703. [PMID: 11504698 DOI: 10.1152/ajplung.2001.281.3.l697] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Both surfactant protein (SP) D and granulocyte-macrophage colony-stimulating factor (GM-CSF) influence pulmonary surfactant homeostasis, with the deficiency of either protein causing marked accumulation of surfactant phospholipids in lung tissues and in the alveoli. To assess whether the effects of each gene were mediated by distinct or shared mechanisms, surfactant homeostasis and lung morphology were assessed in 1) double-transgenic mice in which both SP-D and GM-CSF genes were ablated [SP-D(-/-),GM(-/-)] and 2) transgenic mice deficient in both SP-D and GM-CSF in which the expression of GM-CSF was increased in the lung. Saturated phosphatidylcholine (Sat PC) pool sizes were markedly increased in SP-D(-/-),GM(-/-) mice, with the effects of each gene deletion on surfactant Sat PC pool sizes being approximately additive. Expression of GM-CSF in lungs of SP-D(-/-),GM(-/-) mice corrected GM-CSF-dependent abnormalities in surfactant catabolism but did not correct lung pathology characteristic of SP-D deletion. In contrast to findings in GM(-/-) mice, degradation of [(3)H]dipalmitoylphosphatidylcholine by alveolar macrophages from the SP-D(-/-) mice was normal. The emphysema and foamy macrophage infiltrates characteristic of SP-D(-/-) mice were similar in the presence or absence of GM-CSF. Taken together, these findings demonstrate the distinct roles of SP-D and GM-CSF in the regulation of surfactant homeostasis and lung structure.
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Affiliation(s)
- M Ikegami
- Division of Pulmonary Biology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
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