1
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Terada K, Endo M, Kiyonari H, Takeda N, Oike Y. Loss of Dja2 accompanies pH deviation in lysosomes and lysosome-related organelles. J Cell Physiol 2024; 239:e31174. [PMID: 38108578 DOI: 10.1002/jcp.31174] [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: 08/02/2023] [Revised: 11/29/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
The Dja2 knockout (Dja2-/- ) mice had respiratory distress, and >60% died within 2 days after birth. The surviving adult Dja2-/- mice were infertile and the lungs of Dja2-/- mice showed several abnormalities, including the processing defect of prosurfactant protein C in the alveolar epithelial type II cells and the accumulation of glycolipids in enlarged alveolar macrophages. The luminal pH of acidic organelles in Dja2-/- cells was shifted to pH 5.37-5.45. This deviated pH was immediately restored to control levels (pH 4.56-4.65) by the addition of a diuretic, ethyl isopropyl amiloride (EIPA). Although the role of DJA2 in maintaining the pH homeostasis of lysosome-related organelles is currently obscure, this rapid and remarkable pH resilience is best explained by an EIPA-sensitive proton efflux machinery that is disorganized and overactivated due to the loss of Dja2.
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Affiliation(s)
- Kazutoyo Terada
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Motoyoshi Endo
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Hiroshi Kiyonari
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamic Research, Kobe, Japan
| | - Naoki Takeda
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto, Japan
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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2
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Neary MT, Mulder LM, Kowalski PS, MacLoughlin R, Crean AM, Ryan KB. Nebulised delivery of RNA formulations to the lungs: From aerosol to cytosol. J Control Release 2024; 366:812-833. [PMID: 38101753 DOI: 10.1016/j.jconrel.2023.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
In the past decade RNA-based therapies such as small interfering RNA (siRNA) and messenger RNA (mRNA) have emerged as new and ground-breaking therapeutic agents for the treatment and prevention of many conditions from viral infection to cancer. Most clinically approved RNA therapies are parenterally administered which impacts patient compliance and adds to healthcare costs. Pulmonary administration via inhalation is a non-invasive means to deliver RNA and offers an attractive alternative to injection. Nebulisation is a particularly appealing method due to the capacity to deliver large RNA doses during tidal breathing. In this review, we discuss the unique physiological barriers presented by the lung to efficient nebulised RNA delivery and approaches adopted to circumvent this problem. Additionally, the different types of nebulisers are evaluated from the perspective of their suitability for RNA delivery. Furthermore, we discuss recent preclinical studies involving nebulisation of RNA and analysis in in vitro and in vivo settings. Several studies have also demonstrated the importance of an effective delivery vector in RNA nebulisation therefore we assess the variety of lipid, polymeric and hybrid-based delivery systems utilised to date. We also consider the outlook for nebulised RNA medicinal products and the hurdles which must be overcome for successful clinical translation. In summary, nebulised RNA delivery has demonstrated promising potential for the treatment of several lung-related conditions such as asthma, COPD and cystic fibrosis, to which the mode of delivery is of crucial importance for clinical success.
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Affiliation(s)
- Michael T Neary
- SSPC, The SFI Research Centre for Pharmaceuticals, School of Pharmacy, University College Cork, Ireland; School of Pharmacy, University College Cork, Ireland
| | | | - Piotr S Kowalski
- School of Pharmacy, University College Cork, Ireland; APC Microbiome, University College Cork, Cork, Ireland
| | | | - Abina M Crean
- SSPC, The SFI Research Centre for Pharmaceuticals, School of Pharmacy, University College Cork, Ireland; School of Pharmacy, University College Cork, Ireland
| | - Katie B Ryan
- SSPC, The SFI Research Centre for Pharmaceuticals, School of Pharmacy, University College Cork, Ireland; School of Pharmacy, University College Cork, Ireland.
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3
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He M, Borlak J. A genomic perspective of the aging human and mouse lung with a focus on immune response and cellular senescence. Immun Ageing 2023; 20:58. [PMID: 37932771 PMCID: PMC10626779 DOI: 10.1186/s12979-023-00373-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 09/12/2023] [Indexed: 11/08/2023]
Abstract
BACKGROUND The aging lung is a complex process and influenced by various stressors, especially airborne pathogens and xenobiotics. Additionally, a lifetime exposure to antigens results in structural and functional changes of the lung; yet an understanding of the cell type specific responses remains elusive. To gain insight into age-related changes in lung function and inflammaging, we evaluated 89 mouse and 414 individual human lung genomic data sets with a focus on genes mechanistically linked to extracellular matrix (ECM), cellular senescence, immune response and pulmonary surfactant, and we interrogated single cell RNAseq data to fingerprint cell type specific changes. RESULTS We identified 117 and 68 mouse and human genes linked to ECM remodeling which accounted for 46% and 27%, respectively of all ECM coding genes. Furthermore, we identified 73 and 31 mouse and human genes linked to cellular senescence, and the majority code for the senescence associated secretory phenotype. These cytokines, chemokines and growth factors are primarily secreted by macrophages and fibroblasts. Single-cell RNAseq data confirmed age-related induced expression of marker genes of macrophages, neutrophil, eosinophil, dendritic, NK-, CD4+, CD8+-T and B cells in the lung of aged mice. This included the highly significant regulation of 20 genes coding for the CD3-T-cell receptor complex. Conversely, for the human lung we primarily observed macrophage and CD4+ and CD8+ marker genes as changed with age. Additionally, we noted an age-related induced expression of marker genes for mouse basal, ciliated, club and goblet cells, while for the human lung, fibroblasts and myofibroblasts marker genes increased with age. Therefore, we infer a change in cellular activity of these cell types with age. Furthermore, we identified predominantly repressed expression of surfactant coding genes, especially the surfactant transporter Abca3, thus highlighting remodeling of surfactant lipids with implications for the production of inflammatory lipids and immune response. CONCLUSION We report the genomic landscape of the aging lung and provide a rationale for its growing stiffness and age-related inflammation. By comparing the mouse and human pulmonary genome, we identified important differences between the two species and highlight the complex interplay of inflammaging, senescence and the link to ECM remodeling in healthy but aged individuals.
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Affiliation(s)
- Meng He
- Centre for Pharmacology and Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Jürgen Borlak
- Centre for Pharmacology and Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
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4
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Shao C, Cao T, Wang X, Fan Q, Ye F. Reconstruction of the alveolar-capillary barrier in vitro based on a photo-responsive stretchable Janus membrane. SMART MEDICINE 2023; 2:e20220035. [PMID: 39188563 PMCID: PMC11235665 DOI: 10.1002/smmd.20220035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/05/2023] [Indexed: 08/28/2024]
Abstract
The lung is the respiratory organ of the human body, and the alveoli are the most basic functional units of the lung. Herein, a photo-responsive stretchable Janus membrane was proposed for the reconstruction of the alveolar-capillary barrier in vitro. This Janus membrane was fabricated by photocrosslinking methylacrylamide gelatin (Gelma) hydrogel and N-isoacrylamide (NIPAM) hydrogel mixed with graphene oxide (GO). The Gelma hydrogel containing large amounts of collagen provides a natural extracellular matrix environment for cell growth, while the temperature-sensitive NIPAM hydrogel combined with GO gives the membrane a light-controlled stretching property. Based on this Janus membrane, an open polydimethylsiloxane chip was established to coculture alveolar epithelial cells and vascular endothelial cells at the air-liquid interface. It was demonstrated that the alveolar epithelial cells cultured on the upper side of the Janus membrane could express epithelial cell marker protein E-cadherin and secrete alveolar surfactant. In addition, VE-cadherin, an endothelium-specific protein located at the junction between endothelial cells, was also detected in vascular endothelial cells cultured on the underside of Janus membrane. The constructed lung tissue model with the dynamically stretchable Janus membrane is well-suited for COVID-19 infection studies and drug testing.
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Affiliation(s)
- Changmin Shao
- Zhejiang Engineering Research Center for Tissue Repair MaterialsWenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiangChina
| | - Ting Cao
- Zhejiang Engineering Research Center for Tissue Repair MaterialsWenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiangChina
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijingChina
| | - Xiaochen Wang
- Zhejiang Engineering Research Center for Tissue Repair MaterialsWenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiangChina
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijingChina
| | - Qihui Fan
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijingChina
| | - Fangfu Ye
- Zhejiang Engineering Research Center for Tissue Repair MaterialsWenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiangChina
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijingChina
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5
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Wasnick R, Korfei M, Piskulak K, Henneke I, Wilhelm J, Mahavadi P, Dartsch RC, von der Beck D, Koch M, Shalashova I, Weiss A, Klymenko O, Askevold I, Fink L, Witt H, Hackstein H, El Agha E, Bellusci S, Klepetko W, Königshoff M, Eickelberg O, Schermuly RT, Braun T, Seeger W, Ruppert C, Guenther A. Notch1 Induces Defective Epithelial Surfactant Processing and Pulmonary Fibrosis. Am J Respir Crit Care Med 2023; 207:283-299. [PMID: 36047984 DOI: 10.1164/rccm.202105-1284oc] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Rationale: Although type II alveolar epithelial cells (AEC2s) are chronically injured in idiopathic pulmonary fibrosis (IPF), they contribute to epithelial regeneration in IPF. Objectives: We hypothesized that Notch signaling may contribute to AEC2 proliferation, dedifferentiation characterized by loss of surfactant processing machinery, and lung fibrosis in IPF. Methods: We applied microarray analysis, kinome profiling, flow cytometry, immunofluorescence analysis, western blotting, quantitative PCR, and proliferation and surface activity analysis to study epithelial differentiation, proliferation, and matrix deposition in vitro (AEC2 lines, primary murine/human AEC2s), ex vivo (human IPF-derived precision-cut lung slices), and in vivo (bleomycin and pepstatin application, Notch1 [Notch receptor 1] intracellular domain overexpression). Measurements and Main Results: We document here extensive SP-B and -C (surfactant protein-B and -C) processing defects in IPF AEC2s, due to loss of Napsin A, resulting in increased intra-alveolar surface tension and alveolar collapse and induction of endoplasmic reticulum stress in AEC2s. In vivo pharmacological inhibition of Napsin A results in the development of AEC2 injury and overt lung fibrosis. We also demonstrate that Notch1 signaling is already activated early in IPF and determines AEC2 fate by inhibiting differentiation (reduced lamellar body compartment, reduced capacity to process hydrophobic SP) and by causing increased epithelial proliferation and development of lung fibrosis, putatively via altered JAK (Janus kinase)/Stat (signal transducer and activator of transcription) signaling in AEC2s. Conversely, inhibition of Notch signaling in IPF-derived precision-cut lung slices improved the surfactant processing capacity of AEC2s and reversed fibrosis. Conclusions: Notch1 is a central regulator of AEC2 fate in IPF. It induces alveolar epithelial proliferation and loss of Napsin A and of surfactant proprotein processing, and it contributes to fibroproliferation.
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Affiliation(s)
- Roxana Wasnick
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Martina Korfei
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Katarzyna Piskulak
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Ingrid Henneke
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Jochen Wilhelm
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Poornima Mahavadi
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany
| | - Ruth Charlotte Dartsch
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Daniel von der Beck
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Miriam Koch
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Lung Clinic, Evangelisches Krankenhaus Mittelhessen, 35398 Giessen, Germany
| | - Irina Shalashova
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Astrid Weiss
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Oleksiy Klymenko
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany
| | - Ingolf Askevold
- Department of Surgery, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Ludger Fink
- Institut für Pathologie, Überregionale Gemeinschaftspraxis für Pathologie und Zytologie, 35578 Wetzlar, Germany
| | - Heiko Witt
- Pediatric Nutritional Medicine, Else-Kröner-Fresenius-Fresenius-Ceter for Nutritional Sciences, Technical University Munich, 85354 Freising, Germany
| | - Holger Hackstein
- Department of Clinical Immunology and Transfusion Medicine, Justus-Liebig University Giessen, 35392 Giessen, Germany
| | - Elie El Agha
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Saverio Bellusci
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Walter Klepetko
- Department of Thoracic Surgery, Vienna General Hospital, 1090 Vienna, Austria
| | - Melanie Königshoff
- Comprehensive Pneumology Center, Research Unit Lung Repair and Regeneration, Helmholtz Center Munich, Ludwig Maximilians University Munich, 81377 Munich, Germany.,Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15261
| | - Oliver Eickelberg
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15261
| | - Ralph Theo Schermuly
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Thomas Braun
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany.,Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany; and
| | - Werner Seeger
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany.,Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany; and
| | - Clemens Ruppert
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,European IPF Registry/Biobank, 35392 Giessen, Germany
| | - Andreas Guenther
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), 35392 Giessen, Germany.,Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany.,Institute for Lung Health (ILH), 35392 Giessen, Germany.,Lung Clinic, Evangelisches Krankenhaus Mittelhessen, 35398 Giessen, Germany.,European IPF Registry/Biobank, 35392 Giessen, Germany
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6
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Cao T, Shao C, Yu X, Xie R, Yang C, Sun Y, Yang S, He W, Xu Y, Fan Q, Ye F. Biomimetic Alveolus-on-a-Chip for SARS-CoV-2 Infection Recapitulation. RESEARCH (WASHINGTON, D.C.) 2022; 2022:9819154. [PMID: 35224503 PMCID: PMC8841031 DOI: 10.34133/2022/9819154] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/13/2022] [Indexed: 01/07/2023]
Abstract
SARS-CoV-2 has caused a severe pneumonia pandemic worldwide with high morbidity and mortality. How to develop a preclinical model for recapitulating SARS-CoV-2 pathogenesis is still urgent and essential for the control of the pandemic. Here, we have established a 3D biomimetic alveolus-on-a-chip with mechanical strain and extracellular matrix taken into consideration. We have validated that the alveolus-on-a-chip is capable of recapitulating key physiological characteristics of human alveolar units, which lays a fundamental basis for viral infection studies at the organ level. Using virus-analogous chemicals and pseudovirus, we have explored virus pathogenesis and blocking ability of antibodies during viral infection. This work provides a favorable platform for SARS-CoV-2-related researches and has a great potential for physiology and pathophysiology studies of the human lung at the organ level in vitro.
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Affiliation(s)
- Ting Cao
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325001, China.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Changmin Shao
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325001, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Xiaoyu Yu
- School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China
| | - Ruipei Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chen Yang
- School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China
| | - Yulong Sun
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325001, China.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Shaohua Yang
- School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China
| | - Wangjian He
- School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China
| | - Ye Xu
- School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China
| | - Qihui Fan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fangfu Ye
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325001, China.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
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7
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Figueira RL, Antounians L, Zani-Ruttenstock E, Khalaj K, Zani A. Fetal lung regeneration using stem cell-derived extracellular vesicles: A new frontier for pulmonary hypoplasia secondary to congenital diaphragmatic hernia. Prenat Diagn 2022; 42:364-372. [PMID: 35191057 DOI: 10.1002/pd.6117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 11/12/2022]
Abstract
The poor outcomes of babies with congenital diaphragmatic hernia (CDH) are directly related to pulmonary hypoplasia, a cosndition characterized by impaired lung development. Although the pathogenesis of pulmonary hypoplasia is not fully elucidated, there is now evidence that CDH patients have missing or dysregulated microRNAs (miRNAs) that regulate lung development. A prenatal therapy that supplements these missing/dysregulated miRNAs could be a strategy to rescue normal lung development. Extracellular vesicles (EVs), also known as exosomes when of small dimensions, are lipid-bound nanoparticles that can transfer their heterogeneous cargo (proteins, lipids, small RNAs) to target cells to induce biological responses. Herein, we review all studies that show evidence for stem cell-derived EVs as a regenerative therapy to rescue normal development in CDH fetal lungs. Particularly, we report studies showing that administration of EVs derived from amniotic fluid stem cells (AFSC-EVs) to models of pulmonary hypoplasia promotes fetal lung growth and maturation via transfer of miRNAs that are known to regulate lung developmental processes. We also describe that stem cell-derived EVs exert effects on vascular remodeling, thus possibly preventing postnatal pulmonary hypertension. Finally, we discuss future perspectives and challenges to translate this promising stem cell EV-based therapy to clinical practice. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Rebeca Lopes Figueira
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Division of General and Thoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Lina Antounians
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Division of General and Thoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Elke Zani-Ruttenstock
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Division of General and Thoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Kasra Khalaj
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Division of General and Thoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Augusto Zani
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Division of General and Thoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada.,Department of Surgery, University of Toronto, Toronto, M5T 1P5, Canada
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8
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Wasnick RM, Shalashova I, Wilhelm J, Khadim A, Schmidt N, Hackstein H, Hecker A, Hoetzenecker K, Seeger W, Bellusci S, El Agha E, Ruppert C, Guenther A. Differential LysoTracker Uptake Defines Two Populations of Distal Epithelial Cells in Idiopathic Pulmonary Fibrosis. Cells 2022; 11:235. [PMID: 35053350 PMCID: PMC8773634 DOI: 10.3390/cells11020235] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 12/18/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal degenerative lung disease of unknown etiology. Although in its final stages it implicates, in a reactive manner, all lung cell types, the initial damage involves the alveolar epithelial compartment, in particular the alveolar epithelial type 2 cells (AEC2s). AEC2s serve dual progenitor and surfactant secreting functions, both of which are deeply impacted in IPF. Thus, we hypothesize that the size of the surfactant processing compartment, as measured by LysoTracker incorporation, allows the identification of different epithelial states in the IPF lung. Flow cytometry analysis of epithelial LysoTracker incorporation delineates two populations (Lysohigh and Lysolow) of AEC2s that behave in a compensatory manner during bleomycin injury and in the donor/IPF lung. Employing flow cytometry and transcriptomic analysis of cells isolated from donor and IPF lungs, we demonstrate that the Lysohigh population expresses all classical AEC2 markers and is drastically diminished in IPF. The Lysolow population, which is increased in proportion in IPF, co-expressed AEC2 and basal cell markers, resembling the phenotype of the previously identified intermediate AEC2 population in the IPF lung. In that regard, we provide an in-depth flow-cytometry characterization of LysoTracker uptake, HTII-280, proSP-C, mature SP-B, NGFR, KRT5, and CD24 expression in human lung epithelial cells. Combining functional analysis with extracellular and intracellular marker expression and transcriptomic analysis, we advance the current understanding of epithelial cell behavior and fate in lung fibrosis.
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Affiliation(s)
- Roxana Maria Wasnick
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
| | - Irina Shalashova
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
| | - Jochen Wilhelm
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany
- Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
- Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Ali Khadim
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Nicolai Schmidt
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
| | - Holger Hackstein
- Department of Clinical Immunology and Transfusion Medicine, 35392 Giessen, Germany;
| | - Andreas Hecker
- Department of General and Thoracic Surgery, University Hospital Giessen, 35392 Giessen, Germany;
| | - Konrad Hoetzenecker
- Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria;
| | - Werner Seeger
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany
- Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
- Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Saverio Bellusci
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany
- Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Elie El Agha
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Institute for Lung Health (ILH), 35392 Giessen, Germany
| | - Clemens Ruppert
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany
- European IPF Registry/UGLMC Giessen Biobank, 35392 Giessen, Germany
| | - Andreas Guenther
- Universities of Giessen and Marburg Lung Center (UGMLC), The German Center for Lung Research (DZL), 35392 Giessen, Germany; (I.S.); (J.W.); (A.K.); (N.S.); (W.S.); (S.B.); (E.E.A.); (C.R.); (A.G.)
- Excellence Cluster Cardiopulmonary Institute (CPI), 35392 Giessen, Germany
- Institute for Lung Health (ILH), 35392 Giessen, Germany
- Department of General and Thoracic Surgery, University Hospital Giessen, 35392 Giessen, Germany;
- European IPF Registry/UGLMC Giessen Biobank, 35392 Giessen, Germany
- Lung Clinic Waldhof-Elgershausen, 35753 Greifenstein, Germany
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9
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Dietl P, Frick M. Channels and Transporters of the Pulmonary Lamellar Body in Health and Disease. Cells 2021; 11:45. [PMID: 35011607 PMCID: PMC8750383 DOI: 10.3390/cells11010045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 02/06/2023] Open
Abstract
The lamellar body (LB) of the alveolar type II (ATII) cell is a lysosome-related organelle (LRO) that contains surfactant, a complex mix of mainly lipids and specific surfactant proteins. The major function of surfactant in the lung is the reduction of surface tension and stabilization of alveoli during respiration. Its lack or deficiency may cause various forms of respiratory distress syndrome (RDS). Surfactant is also part of the innate immune system in the lung, defending the organism against air-borne pathogens. The limiting (organelle) membrane that encloses the LB contains various transporters that are in part responsible for translocating lipids and other organic material into the LB. On the other hand, this membrane contains ion transporters and channels that maintain a specific internal ion composition including the acidic pH of about 5. Furthermore, P2X4 receptors, ligand gated ion channels of the danger signal ATP, are expressed in the limiting LB membrane. They play a role in boosting surfactant secretion and fluid clearance. In this review, we discuss the functions of these transporting pathways of the LB, including possible roles in disease and as therapeutic targets, including viral infections such as SARS-CoV-2.
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Affiliation(s)
- Paul Dietl
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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10
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Schiefermeier-Mach N, Perkhofer S, Heinrich L, Haller T. Stimulation of surfactant exocytosis in primary alveolar type II cells by A. fumigatus. Med Mycol 2021; 59:168-179. [PMID: 32459847 DOI: 10.1093/mmy/myaa042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/06/2020] [Accepted: 04/30/2020] [Indexed: 02/06/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen with small airborne spores (conidia) that may escape clearance by upper airways and directly impact the alveolar epithelium. Consequently, innate alveolar defense mechanisms are being activated, including professional phagocytosis by alveolar macrophages, recruitment of circulating neutrophils and probably enhanced secretion of pulmonary surfactant by the alveolar type II (AT II) cells. However, no data are available in support of the latter hypothesis. We therefore used a coculture model of GFP-Aspergillus conidia with primary rat AT II cells and studied fungal growth, cellular Ca2+ homeostasis, and pulmonary surfactant exocytosis by live cell video microscopy. We observed all stages of fungal development, including reversible attachment, binding and internalization of conidia as well as conidial swelling, formation of germ tubes and outgrowth of hyphae. In contrast to resting conidia, which did not provoke immediate cellular effects, metabolically active conidia, fungal cellular extracts (CE) and fungal culture filtrates (CF) prepared from swollen conidia caused a Ca2+-independent exocytosis. Ca2+ signals of greatly varying delays, durations and amplitudes were observed by applying CE or CF obtained from hyphae of A. fumigatus, suggesting compounds secreted by filamentous A. fumigatus that severely interfere with AT II cell Ca2+ homeostasis. The mechanisms underlying the stimulatory effects, with respect to exocytosis and Ca2+ signaling, are unclear and need to be identified.
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Affiliation(s)
| | - Susanne Perkhofer
- FH Gesundheit, Health University of Applied Sciences Tyrol, Innrain 98, A-6020 Innsbruck, Austria
| | - Lea Heinrich
- FH Gesundheit, Health University of Applied Sciences Tyrol, Innrain 98, A-6020 Innsbruck, Austria.,Department of Physiology and Medical Physics, Institute of Physiology, Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck, Austria
| | - Thomas Haller
- Department of Physiology and Medical Physics, Institute of Physiology, Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck, Austria
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11
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Paget TL, Parkinson-Lawrence EJ, Trim PJ, Autilio C, Panchal MH, Koster G, Echaide M, Snel MF, Postle AD, Morrison JL, Pérez-Gil J, Orgeig S. Increased Alveolar Heparan Sulphate and Reduced Pulmonary Surfactant Amount and Function in the Mucopolysaccharidosis IIIA Mouse. Cells 2021; 10:849. [PMID: 33918094 PMCID: PMC8070179 DOI: 10.3390/cells10040849] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 02/07/2023] Open
Abstract
Mucopolysaccharidosis IIIA (MPS IIIA) is a lysosomal storage disease with significant neurological and skeletal pathologies. Respiratory dysfunction is a secondary pathology contributing to mortality in MPS IIIA patients. Pulmonary surfactant is crucial to optimal lung function and has not been investigated in MPS IIIA. We measured heparan sulphate (HS), lipids and surfactant proteins (SP) in pulmonary tissue and bronchoalveolar lavage fluid (BALF), and surfactant activity in healthy and diseased mice (20 weeks of age). Heparan sulphate, ganglioside GM3 and bis(monoacylglycero)phosphate (BMP) were increased in MPS IIIA lung tissue. There was an increase in HS and a decrease in BMP and cholesteryl esters (CE) in MPS IIIA BALF. Phospholipid composition remained unchanged, but BALF total phospholipids were reduced (49.70%) in MPS IIIA. There was a reduction in SP-A, -C and -D mRNA, SP-D protein in tissue and SP-A, -C and -D protein in BALF of MPS IIIA mice. Captive bubble surfactometry showed an increase in minimum and maximum surface tension and percent surface area compression, as well as a higher compressibility and hysteresis in MPS IIIA surfactant upon dynamic cycling. Collectively these biochemical and biophysical changes in alveolar surfactant are likely to be detrimental to lung function in MPS IIIA.
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Affiliation(s)
- Tamara L. Paget
- Mechanisms in Cell Biology and Disease Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia; (T.L.P.); (E.J.P.-L.)
| | - Emma J. Parkinson-Lawrence
- Mechanisms in Cell Biology and Disease Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia; (T.L.P.); (E.J.P.-L.)
| | - Paul J. Trim
- Proteomics, Metabolomics and MS-Imaging Core Facility, South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia; (P.J.T.); (M.F.S.)
| | - Chiara Autilio
- Department of Biochemistry, Faculty of Biology and Research Institute Hospital 12 de Octubre (Imas12), Complutense University, 28003 Madrid, Spain; (C.A.); (M.E.); (J.P.-G.)
| | - Madhuriben H. Panchal
- Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (M.H.P.); (G.K.); (A.D.P.)
| | - Grielof Koster
- Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (M.H.P.); (G.K.); (A.D.P.)
| | - Mercedes Echaide
- Department of Biochemistry, Faculty of Biology and Research Institute Hospital 12 de Octubre (Imas12), Complutense University, 28003 Madrid, Spain; (C.A.); (M.E.); (J.P.-G.)
| | - Marten F. Snel
- Proteomics, Metabolomics and MS-Imaging Core Facility, South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia; (P.J.T.); (M.F.S.)
| | - Anthony D. Postle
- Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (M.H.P.); (G.K.); (A.D.P.)
| | - Janna L. Morrison
- Early Origins Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia;
| | - Jésus Pérez-Gil
- Department of Biochemistry, Faculty of Biology and Research Institute Hospital 12 de Octubre (Imas12), Complutense University, 28003 Madrid, Spain; (C.A.); (M.E.); (J.P.-G.)
| | - Sandra Orgeig
- Mechanisms in Cell Biology and Disease Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia; (T.L.P.); (E.J.P.-L.)
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12
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Harney J, Bajaj P, Finley JE, Kopec AK, Koza-Taylor PH, Boucher GG, Lanz TA, Doshna CM, Somps CJ, Adkins K, Houle C. An in vitro alveolar epithelial cell model recapitulates LRRK2 inhibitor-induced increases in lamellar body size observed in preclinical models. Toxicol In Vitro 2021; 70:105012. [DOI: 10.1016/j.tiv.2020.105012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 09/14/2020] [Accepted: 10/05/2020] [Indexed: 01/28/2023]
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13
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Chakraborty S, Winkelmann VE, Braumüller S, Palmer A, Schultze A, Klohs B, Ignatius A, Vater A, Fauler M, Frick M, Huber-Lang M. Role of the C5a-C5a receptor axis in the inflammatory responses of the lungs after experimental polytrauma and hemorrhagic shock. Sci Rep 2021; 11:2158. [PMID: 33495506 PMCID: PMC7835219 DOI: 10.1038/s41598-020-79607-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022] Open
Abstract
Singular blockade of C5a in experimental models of sepsis is known to confer protection by rescuing lethality and decreasing pro-inflammatory responses. However, the role of inhibiting C5a has not been evaluated in the context of sterile systemic inflammatory responses, like polytrauma and hemorrhagic shock (PT + HS). In our presented study, a novel and highly specific C5a L-aptamer, NoxD21, was used to block C5a activity in an experimental murine model of PT + HS. The aim of the study was to assess early modulation of inflammatory responses and lung damage 4 h after PT + HS induction. NoxD21-treated PT + HS mice displayed greater polymorphonuclear cell recruitment in the lung, increased pro-inflammatory cytokine levels in the bronchoalveolar lavage fluids (BALF) and reduced myeloperoxidase levels within the lung tissue. An in vitro model of the alveolar-capillary barrier was established to confirm these in vivo observations. Treatment with a polytrauma cocktail induced barrier damage only after 16 h, and NoxD21 treatment in vitro did not rescue this effect. Furthermore, to test the exact role of both the cognate receptors of C5a (C5aR1 and C5aR2), experimental PT + HS was induced in C5aR1 knockout (C5aR1 KO) and C5aR2 KO mice. Following 4 h of PT + HS, C5aR2 KO mice had significantly reduced IL-6 and IL-17 levels in the BALF without significant lung damage, and both, C5aR1 KO and C5aR2 KO PT + HS animals displayed reduced MPO levels within the lungs. In conclusion, the C5aR2 could be a putative driver of early local inflammatory responses in the lung after PT + HS.
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Affiliation(s)
- Shinjini Chakraborty
- Institute of Clinical and Experimental Trauma-Immunology, Ulm University Medical Center, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Veronika Eva Winkelmann
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Sonja Braumüller
- Institute of Clinical and Experimental Trauma-Immunology, Ulm University Medical Center, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Annette Palmer
- Institute of Clinical and Experimental Trauma-Immunology, Ulm University Medical Center, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Anke Schultze
- Institute of Clinical and Experimental Trauma-Immunology, Ulm University Medical Center, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Bettina Klohs
- Institute of Clinical and Experimental Trauma-Immunology, Ulm University Medical Center, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Ulm University Medical Center, Helmholtzstrasse 14, 89081, Ulm, Germany
| | - Axel Vater
- Aptarion Biotech AG, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Michael Fauler
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma-Immunology, Ulm University Medical Center, Helmholtzstrasse 8/1, 89081, Ulm, Germany.
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14
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Migrating Lung Monocytes Internalize and Inhibit Growth of Aspergillus fumigatus Conidia. Pathogens 2020; 9:pathogens9120983. [PMID: 33255432 PMCID: PMC7760852 DOI: 10.3390/pathogens9120983] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/18/2020] [Accepted: 11/23/2020] [Indexed: 12/24/2022] Open
Abstract
Monocytes are important players to combat the ubiquitously present fungus Aspergillus fumigatus. Recruitment of monocytes to sites of fungal A. fumigatus infection has been shown in vivo. Upon exposure to A. fumigatus in vitro, purified murine and human blood monocytes secrete inflammatory cytokines and fungicidal mediators. Mononuclear tissue phagocytes are phenotypically and functionally different from those circulating in the blood and their role in antifungal defenses is much less understood. In this study, we identified a population of migrating CD43+ monocytes in cells isolated from rat distal lungs. These cells are phenotypically different from alveolar macrophages and show distinct locomotory behavior on the surface of primary alveolar cells resembling previously described endothelial patrolling monocytes. Upon challenge, the CD43+ monocytes internalized A. fumigatus conidia resulting in inhibition of their germination and hyphal growth. Thus, migrating lung monocytes might play an important role in local defense against pulmonary pathogens.
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15
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Abstract
Purpose of Review Lung tissues are highly susceptible to airway inflammation as they are inevitably exposed to inhaled pathogens and allergens. In the lungs, clearance of infectious agents and regulation of inflammatory responses are important for the first-line defense, where surfactants play a role in host defense mechanisms. In this review, clinical significance of pulmonary surfactants in asthma has been highlighted. Recent Findings Surfactants, such as surfactant protein A (SP-A) and SP-D released from alveolar epithelium, reduce pathogen infection and control immune-cell activation. Especially, SP-D directly binds to eosinophil surface, leading to inhibition of extracellular trap formation and reduction in airway inflammation. Production of surfactants is commonly determined by both genetic (single nucleotide polymorphisms) and environmental factors influencing processes involved in the development of asthma. In addition, nintedanib (an intracellular inhibitor of tyrosine kinases) could increase SP-D levels and is used in patients with idiopathic pulmonary fibrosis. These findings may provide a possible application of SP-D in asthma. Summary Surfactants are key players contributing to host defense through maintaining the immune system. As clinical implications of surfactants involved in asthma have been suggested, further translational studies are needed to apply surfactants as an effective therapeutic target in patients with asthma.
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Affiliation(s)
- Youngwoo Choi
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, South Korea
| | - Jaehyuk Jang
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, South Korea
| | - Hae-Sim Park
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, South Korea.
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16
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Diem K, Fauler M, Fois G, Hellmann A, Winokurow N, Schumacher S, Kranz C, Frick M. Mechanical stretch activates piezo1 in caveolae of alveolar type I cells to trigger ATP release and paracrine stimulation of surfactant secretion from alveolar type II cells. FASEB J 2020; 34:12785-12804. [PMID: 32744386 DOI: 10.1096/fj.202000613rrr] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/14/2020] [Accepted: 07/16/2020] [Indexed: 12/12/2022]
Abstract
Secretion of pulmonary surfactant in the alveoli of the lungs is essential to maintain lung function. Stretching of alveoli during lung inflation is the main trigger for surfactant secretion. Yet, the molecular mechanisms how mechanical distension of alveoli results in surfactant secretion are still elusive. The alveolar epithelium consists of alveolar epithelial type I (ATI) and surfactant secreting type II (ATII) cells. ATI, but not ATII cells, express caveolae, small plasma membrane invaginations that can respond to plasma membrane stresses and serve mechanotransductive roles. Within this study, we investigated the role of caveolae as mechanosensors in the alveolus. We generated a human caveolin-1 knockout ATI cell (hAELVicav-/- ) using CRISPR/Cas9. Wildtype (hAELViwt ) and hAELVicav-/- cells grown on flexible membranes responded to increasing stretch amplitudes with rises in intracellular Ca2+ . The response was less frequent and started at higher stretch amplitudes in hAELVicav-/- cells. Stretch-induced Ca2+ -signals depended on Ca2+ -entry via piezo1 channels, localized within caveolae in hAELViwt and primary ATI cells. Ca2+ -entry via piezo1 activated pannexin-1 hemichannels resulting in ATP release from ATI cells. ATP release was reduced in hAELVicav-/- cells. In co-cultures resembling the alveolar epithelium, released ATP stimulated Ca2+ signals and surfactant secretion from neighboring ATII cells when co-cultured with hAELViwt but not hAELVicav-/- cells. In summary, we propose that caveolae in ATI cells are mechanosensors within alveoli regulating stretch-induced surfactant secretion from ATII cells.
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Affiliation(s)
- Kathrin Diem
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Giorgio Fois
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Andreas Hellmann
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany
| | - Natalie Winokurow
- Institute of Molecular and Cellular Anatomy, Ulm University, Ulm, Germany
| | - Stefan Schumacher
- Institute of Molecular and Cellular Anatomy, Ulm University, Ulm, Germany
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Ulm, Germany
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17
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Holme JA, Brinchmann BC, Le Ferrec E, Lagadic-Gossmann D, Øvrevik J. Combustion Particle-Induced Changes in Calcium Homeostasis: A Contributing Factor to Vascular Disease? Cardiovasc Toxicol 2020; 19:198-209. [PMID: 30955163 DOI: 10.1007/s12012-019-09518-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Air pollution is the leading environmental risk factor for disease and premature death in the world. This is mainly due to exposure to urban air particle matter (PM), in particular, fine and ultrafine combustion-derived particles (CDP) from traffic-related air pollution. PM and CDP, including particles from diesel exhaust (DEP), and cigarette smoke have been linked to various cardiovascular diseases (CVDs) including atherosclerosis, but the underlying cellular mechanisms remain unclear. Moreover, CDP typically consist of carbon cores with a complex mixture of organic chemicals such as polycyclic aromatic hydrocarbons (PAHs) adhered. The relative contribution of the carbon core and adhered soluble components to cardiovascular effects of CDP is still a matter of discussion. In the present review, we summarize evidence showing that CDP affects intracellular calcium regulation, and argue that CDP-induced impairment of normal calcium control may be a critical cellular event through which CDP exposure contributes to development or exacerbation of cardiovascular disease. Furthermore, we highlight in vitro research suggesting that adhered organic chemicals such as PAHs may be key drivers of these responses. CDP, extractable organic material from CDP (CDP-EOM), and PAHs may increase intracellular calcium levels by interacting with calcium channels like transient receptor potential (TRP) channels, and receptors such as G protein-coupled receptors (GPCR; e.g., beta-adrenergic receptors [βAR] and protease-activated receptor 2 [PAR-2]) and the aryl hydrocarbon receptor (AhR). Clarifying a possible role of calcium signaling and mechanisms involved may increase our understanding of how air pollution contributes to CVD.
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Affiliation(s)
- Jørn A Holme
- Department of Air Pollution and Noise, Division of Infection Control, Environment and Health, Norwegian Institute of Public Health, PO Box 4404, Nydalen, 0403, Oslo, Norway.
| | - Bendik C Brinchmann
- Department of Air Pollution and Noise, Division of Infection Control, Environment and Health, Norwegian Institute of Public Health, PO Box 4404, Nydalen, 0403, Oslo, Norway
| | - Eric Le Ferrec
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé environnement et travail) - UMR_S 1085, 35000, Rennes, France
| | - Dominique Lagadic-Gossmann
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé environnement et travail) - UMR_S 1085, 35000, Rennes, France
| | - Johan Øvrevik
- Department of Air Pollution and Noise, Division of Infection Control, Environment and Health, Norwegian Institute of Public Health, PO Box 4404, Nydalen, 0403, Oslo, Norway.
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.
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18
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Müller MT, Schempp R, Lutz A, Felder T, Felder E, Miklavc P. Interaction of microtubules and actin during the post-fusion phase of exocytosis. Sci Rep 2019; 9:11973. [PMID: 31427591 PMCID: PMC6700138 DOI: 10.1038/s41598-019-47741-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/09/2019] [Indexed: 01/24/2023] Open
Abstract
Exocytosis is the intracellular trafficking step where a secretory vesicle fuses with the plasma membrane to release vesicle content. Actin and microtubules both play a role in exocytosis; however, their interplay is not understood. Here we study the interaction of actin and microtubules during exocytosis in lung alveolar type II (ATII) cells that secrete surfactant from large secretory vesicles. Surfactant extrusion is facilitated by an actin coat that forms on the vesicle shortly after fusion pore opening. Actin coat compression allows hydrophobic surfactant to be released from the vesicle. We show that microtubules are localized close to actin coats and stay close to the coats during their compression. Inhibition of microtubule polymerization by colchicine and nocodazole affected the kinetics of actin coat formation and the extent of actin polymerisation on fused vesicles. In addition, microtubule and actin cross-linking protein IQGAP1 localized to fused secretory vesicles and IQGAP1 silencing influenced actin polymerisation after vesicle fusion. This study demonstrates that microtubules can influence actin coat formation and actin polymerization on secretory vesicles during exocytosis.
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Affiliation(s)
- M Tabitha Müller
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Rebekka Schempp
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Anngrit Lutz
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Tatiana Felder
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Edward Felder
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Pika Miklavc
- School of Environment and Life Sciences, University of Salford, The Crescent, M54WT, Salford, United Kingdom.
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19
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Prieto P, Clemedson C, Meneguz A, Pfaller W, Sauer UG, Westmoreland C. 3.6. Subacute and Subchronic Toxicity. Altern Lab Anim 2019; 33 Suppl 1:109-16. [PMID: 16194144 DOI: 10.1177/026119290503301s12] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Pilar Prieto
- ECVAM, Institute for Health and Consumer Protection, European Commission Joint Research Centre, 21020 Ispra (VA), Italy
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20
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Korogi Y, Gotoh S, Ikeo S, Yamamoto Y, Sone N, Tamai K, Konishi S, Nagasaki T, Matsumoto H, Ito I, Chen-Yoshikawa TF, Date H, Hagiwara M, Asaka I, Hotta A, Mishima M, Hirai T. In Vitro Disease Modeling of Hermansky-Pudlak Syndrome Type 2 Using Human Induced Pluripotent Stem Cell-Derived Alveolar Organoids. Stem Cell Reports 2019; 12:431-440. [PMID: 30773483 PMCID: PMC6409438 DOI: 10.1016/j.stemcr.2019.01.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 01/05/2023] Open
Abstract
It has been challenging to generate in vitro models of alveolar lung diseases, as the stable culture of alveolar type 2 (AT2) cells has been difficult. Methods of generating and expanding AT2 cells derived from induced pluripotent stem cells (iPSCs) have been established and are expected to be applicable to disease modeling. Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by dysfunction of lysosome-related organelles, such as lamellar bodies (LBs), in AT2 cells. From an HPS type 2 (HPS2) patient, we established disease-specific iPSCs (HPS2-iPSCs) and their gene-corrected counterparts. By live cell imaging, the LB dynamics were visualized and altered distribution, enlargement, and impaired secretion of LBs were demonstrated in HPS2-iPSC-derived AT2 cells. These findings provide insight into the AT2 dysfunction in HPS patients and support the potential use of human iPSC-derived AT2 cells for future research on alveolar lung diseases. HPS2-iPSCs and cHPS2-iPSCs were generated from HPS2 patient fibroblasts Anti-NaPi2b antibody was useful for isolating AT2 cells from human lung and AOs The enlargement and abnormal distribution of LBs were observed in HPS2-AOs Impaired surfactant secretion was demonstrated in HPS2-AOs
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Affiliation(s)
- Yohei Korogi
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Shimpei Gotoh
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan; Department of Drug Discovery for Lung Diseases, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
| | - Satoshi Ikeo
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yuki Yamamoto
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Naoyuki Sone
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Koji Tamai
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Satoshi Konishi
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Tadao Nagasaki
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Hisako Matsumoto
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Isao Ito
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Toyofumi F Chen-Yoshikawa
- Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Hiroshi Date
- Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Masatoshi Hagiwara
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Isao Asaka
- Department of Fundamental Cell Technology, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Akitsu Hotta
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Michiaki Mishima
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Toyohiro Hirai
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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The Regenerative Potential of Amniotic Fluid Stem Cell Extracellular Vesicles: Lessons Learned by Comparing Different Isolation Techniques. Sci Rep 2019; 9:1837. [PMID: 30755672 PMCID: PMC6372651 DOI: 10.1038/s41598-018-38320-w] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 12/20/2018] [Indexed: 12/30/2022] Open
Abstract
Extracellular vesicles (EVs) derived from amniotic fluid stem cells (AFSCs) mediate anti-apoptotic, pro-angiogenic, and immune-modulatory effects in multiple disease models, such as skeletal muscle atrophy and Alport syndrome. A source of potential variability in EV biological functions is how EV are isolated from parent cells. Currently, a comparative study of different EV isolation strategies using conditioned medium from AFSCs is lacking. Herein, we examined different isolation strategies for AFSC-EVs, using common techniques based on differential sedimentation (ultracentrifugation), solubility (ExoQuick, Total Exosome Isolation Reagent, Exo-PREP), or size-exclusion chromatography (qEV). All techniques isolated AFSC-EVs with typical EV morphology and protein markers. In contrast, AFSC-EV size, protein content, and yield varied depending on the method of isolation. When equal volumes of the different AFSC-EV preparations were used as treatment in a model of lung epithelial injury, we observed a significant variation in how AFSC-EVs were able to protect against cell death. AFSC-EV enhancement of cell survival appeared to be dose dependent, and largely uninfluenced by variation in EV-size distributions, relative EV-purity, or their total protein content. The variation in EV-mediated cell survival obtained with different isolation strategies emphasizes the importance of testing alternative isolation techniques in order to maximize EV regenerative capacity.
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22
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Culture of human alveolar epithelial type II cells by sprouting. Respir Res 2018; 19:204. [PMID: 30340591 PMCID: PMC6195695 DOI: 10.1186/s12931-018-0906-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 10/01/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Type II alveolar epithelial cells (AT2) play a pivotal role in maintaining the integrity and function of the alveoli. Only recently, the role of impaired epithelial repair mechanisms after injury in the pathogenesis of idiopathic pulmonary fibrosis has been demonstrated, and has shifted the AT2 cell in the focus of interest. Therefore, using primary human AT2 cells instead of cell lines for in vitro experiments has become desirable. Several groups have developed methods to isolate human AT2 cells applying tissue digestion and consecutive filtration in their protocols. Here we present a technique to isolate primary human AT2 cells by sprouting directly from peripheral human lung tissue. METHODS Epithelial cell cultures were established from lung tissue obtained from patients undergoing diagnostic or therapeutic video-assisted thoracoscopic surgery or undergoing flexible bronchoscopy with transbronchial biopsy. Lung tissue was cut into small pieces and those were placed into cell culture flasks containing supplemented epithelial growth medium for cell sprouting. Cells were characterized by immunofluorescence stainings for E-cadherin, pan-cytokeratin, surfactant protein C (SP-C), and for lysotracker; fluorescent surfactant associated protein B (SP-B) uptake and secretion was assessed by live cell imaging; RNA levels of SP-A, SP-B, SP-C, and SP-D were determined by real-time PCR; Electron microscopy was used to search for the presence of lamellar bodies. RESULTS Sprouting of cells started two to four days after the start of culture. Epithelial differentiation was confirmed by positive staining for E-cadherin and pan-cytokeratin. Further characterization demonstrated positivity for the AT2 cell marker SP-C and for lysotracker which selectively labels lamellar bodies in cultured AT2 cells. The up-take and release of SP-B, a mechanism described for AT2 cells only, was demonstrated by live cell imaging. Real-time RT-PCR showed mRNA expression of all four surfactant proteins with highest levels for SP-B. The presence of lamellar bodies was demonstrated by electron microscopy. CONCLUSIONS This study describes a novel method for isolating AT2 cells from human adult lung tissue by sprouting. The characterization of the cultured AT2 cells complies with current criteria for an alveolar type 2 cell phenotype. Compared to current protocols for the culture of AT2 cells, isolating the cells by sprouting is simple, avoids proteolytic tissue digestion, and has the advantage to be successful even from as few tissue as attained from a transbronchial forceps biopsy.
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Güldner A, Huhle R, Beda A, Kiss T, Bluth T, Rentzsch I, Kerber S, Carvalho NC, Kasper M, Pelosi P, de Abreu MG. Periodic Fluctuation of Tidal Volumes Further Improves Variable Ventilation in Experimental Acute Respiratory Distress Syndrome. Front Physiol 2018; 9:905. [PMID: 30050467 PMCID: PMC6052143 DOI: 10.3389/fphys.2018.00905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/21/2018] [Indexed: 11/28/2022] Open
Abstract
In experimental acute respiratory distress syndrome (ARDS), random variation of tidal volumes (VT) during volume controlled ventilation improves gas exchange and respiratory system mechanics (so-called stochastic resonance hypothesis). It is unknown whether those positive effects may be further enhanced by periodic VT fluctuation at distinct frequencies, also known as deterministic frequency resonance. We hypothesized that the positive effects of variable ventilation on lung function may be further amplified by periodic VT fluctuation at specific frequencies. In anesthetized and mechanically ventilated pigs, severe ARDS was induced by saline lung lavage and injurious VT (double-hit model). Animals were then randomly assigned to 6 h of protective ventilation with one of four VT patterns: (1) random variation of VT (WN); (2) P04, main VT frequency of 0.13 Hz; (3) P10, main VT frequency of 0.05 Hz; (4) VCV, conventional non-variable volume controlled ventilation. In groups with variable VT, the coefficient of variation was identical (30%). We assessed lung mechanics and gas exchange, and determined lung histology and inflammation. Compared to VCV, WN, P04, and P10 resulted in lower respiratory system elastance (63 ± 13 cm H2O/L vs. 50 ± 14 cm H2O/L, 48.4 ± 21 cm H2O/L, and 45.1 ± 5.9 cm H2O/L respectively, P < 0.05 all), but only P10 improved PaO2/FIO2 after 6 h of ventilation (318 ± 96 vs. 445 ± 110 mm Hg, P < 0.05). Cycle-by-cycle analysis of lung mechanics suggested intertidal recruitment/de-recruitment in P10. Lung histologic damage and inflammation did not differ among groups. In this experimental model of severe ARDS, periodic VT fluctuation at a frequency of 0.05 Hz improved oxygenation during variable ventilation, suggesting that deterministic resonance adds further benefit to variable ventilation.
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Affiliation(s)
- Andreas Güldner
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Robert Huhle
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Alessandro Beda
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Departamento de Engenharia Eletrônica, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Thomas Kiss
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Thomas Bluth
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Ines Rentzsch
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Department of Orthodontics, Technische Universität Dresden, Dresden, Germany
| | - Sarah Kerber
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Nadja C Carvalho
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Departamento de Engenharia Eletrônica, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Michael Kasper
- Institute of Anatomy, Technische Universität Dresden, Dresden, Germany
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, IRCCS San Martino IST, University of Genoa, Genoa, Italy
| | - Marcelo G de Abreu
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Haller T, Cerrada A, Pfaller K, Braubach P, Felder E. Polarized light microscopy reveals physiological and drug-induced changes in surfactant membrane assembly in alveolar type II pneumocytes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1152-1161. [DOI: 10.1016/j.bbamem.2018.01.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 12/05/2017] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
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25
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Martínez‐Calle M, Olmeda B, Dietl P, Frick M, Pérez‐Gil J. Pulmonary surfactant protein SP‐B promotes exocytosis of lamellar bodies in alveolar type II cells. FASEB J 2018. [DOI: 10.1096/fj.201701462rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Marta Martínez‐Calle
- Department of Biochemistry and Molecular BiologyFaculty of BiologyComplutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre”Complutense UniversityMadridSpain
| | - Bárbara Olmeda
- Department of Biochemistry and Molecular BiologyFaculty of BiologyComplutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre”Complutense UniversityMadridSpain
| | - Paul Dietl
- Institute of General PhysiologyUlm UniversityUlmGermany
| | - Manfred Frick
- Institute of General PhysiologyUlm UniversityUlmGermany
| | - Jesús Pérez‐Gil
- Department of Biochemistry and Molecular BiologyFaculty of BiologyComplutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre”Complutense UniversityMadridSpain
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26
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Fois G, Winkelmann VE, Bareis L, Staudenmaier L, Hecht E, Ziller C, Ehinger K, Schymeinsky J, Kranz C, Frick M. ATP is stored in lamellar bodies to activate vesicular P2X 4 in an autocrine fashion upon exocytosis. J Gen Physiol 2017; 150:277-291. [PMID: 29282210 PMCID: PMC5806682 DOI: 10.1085/jgp.201711870] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/12/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022] Open
Abstract
P2X4 receptor activation facilitates secretion of pulmonary surfactant from secretory vesicles called lamellar bodies in alveolar epithelial cells. Fois et al. reveal that P2X4 receptors on the lamellar body membranes are activated by ATP stored within the vesicles themselves upon vesicle exocytosis. Vesicular P2X4 receptors are known to facilitate secretion and activation of pulmonary surfactant in the alveoli of the lungs. P2X4 receptors are expressed in the membrane of lamellar bodies (LBs), large secretory lysosomes that store lung surfactant in alveolar type II epithelial cells, and become inserted into the plasma membrane after exocytosis. Subsequent activation of P2X4 receptors by adenosine triphosphate (ATP) results in local fusion-activated cation entry (FACE), facilitating fusion pore dilation, surfactant secretion, and surfactant activation. Despite the importance of ATP in the alveoli, and hence lung function, the origin of ATP in the alveoli is still elusive. In this study, we demonstrate that ATP is stored within LBs themselves at a concentration of ∼1.9 mM. ATP is loaded into LBs by the vesicular nucleotide transporter but does not activate P2X4 receptors because of the low intraluminal pH (5.5). However, the rise in intravesicular pH after opening of the exocytic fusion pore results in immediate activation of vesicular P2X4 by vesicular ATP. Our data suggest a new model in which agonist (ATP) and receptor (P2X4) are located in the same intracellular compartment (LB), protected from premature degradation (ATP) and activation (P2X4), and ideally placed to ensure coordinated and timely receptor activation as soon as fusion occurs to facilitate surfactant secretion.
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Affiliation(s)
- Giorgio Fois
- Institute of General Physiology, Ulm University, Ulm, Germany
| | | | - Lara Bareis
- Institute of General Physiology, Ulm University, Ulm, Germany
| | | | - Elena Hecht
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Charlotte Ziller
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany
| | | | - Jürgen Schymeinsky
- Immunology and Respiratory Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß, Germany
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Ulm, Germany
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27
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Malacrida L, Astrada S, Briva A, Bollati-Fogolín M, Gratton E, Bagatolli LA. Spectral phasor analysis of LAURDAN fluorescence in live A549 lung cells to study the hydration and time evolution of intracellular lamellar body-like structures. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1858:2625-2635. [PMID: 27480804 PMCID: PMC5045802 DOI: 10.1016/j.bbamem.2016.07.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 07/25/2016] [Accepted: 07/27/2016] [Indexed: 10/21/2022]
Abstract
Using LAURDAN spectral imaging and spectral phasor analysis we concurrently studied the growth and hydration state of subcellular organelles (lamellar body-like, LB-like) from live A549 lung cancer cells at different post-confluence days. Our results reveal a time dependent two-step process governing the size and hydration of these intracellular LB-like structures. Specifically, a first step (days 1 to 7) is characterized by an increase in their size, followed by a second one (days 7 to 14) where the organelles display a decrease in their global hydration properties. Interestingly, our results also show that their hydration properties significantly differ from those observed in well-characterized artificial lamellar model membranes, challenging the notion that a pure lamellar membrane organization is present in these organelles at intracellular conditions. Finally, these LB-like structures show a significant increase in their hydration state upon secretion, suggesting a relevant role of entropy during this process.
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Affiliation(s)
- Leonel Malacrida
- Área de Investigación Respiratoria, Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Uruguay; Unidad de Bioquímica y Proteómica Analítica, Institut Pasteur de Montevideo, Uruguay; Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California at Irvine, Irvine, CA, USA.
| | - Soledad Astrada
- Unidad de Biología Celular, Institut Pasteur de Montevideo, Uruguay
| | - Arturo Briva
- Área de Investigación Respiratoria, Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Uruguay
| | | | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California at Irvine, Irvine, CA, USA
| | - Luis A Bagatolli
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Odense M, Denmark.
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Lung surfactant metabolism: early in life, early in disease and target in cell therapy. Cell Tissue Res 2016; 367:721-735. [PMID: 27783217 DOI: 10.1007/s00441-016-2520-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/27/2016] [Indexed: 01/07/2023]
Abstract
Lung surfactant is a complex mixture of lipids and proteins lining the alveolar epithelium. At the air-liquid interface, surfactant lowers surface tension, avoiding alveolar collapse and reducing the work of breathing. The essential role of lung surfactant in breathing and therefore in life, is highlighted by surfactant deficiency in premature neonates, which causes neonatal respiratory distress syndrome and results in early death after birth. In addition, defects in surfactant metabolism alter lung homeostasis and lead to disease. Special attention should be paid to two important key cells responsible for surfactant metabolism: alveolar epithelial type II cells (AE2C) and alveolar macrophages (AM). On the one hand, surfactant deficiency coming from abnormal AE2C function results in high surface tension, promoting alveolar collapse and mechanical stress in the epithelium. This epithelial injury contributes to tissue remodeling and lung fibrosis. On the other hand, impaired surfactant catabolism by AM leads to accumulation of surfactant in air spaces and the associated altered lung function in pulmonary alveolar proteinosis (PAP). We review here two recent cell therapies that aim to recover the activity of AE2C or AM, respectively, therefore targeting the restoring of surfactant metabolism and lung homeostasis. Applied therapies successfully show either transplantation of healthy AE2C in fibrotic lungs, to replace injured AE2C cells and surfactant, or transplantation of bone marrow-derived macrophages to counteract accumulation of surfactant lipid and proteinaceous material in the alveolar spaces leading to PAP. These therapies introduce an alternative treatment with great potential for patients suffering from lung diseases.
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29
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Olmeda B, Martínez-Calle M, Pérez-Gil J. Pulmonary surfactant metabolism in the alveolar airspace: Biogenesis, extracellular conversions, recycling. Ann Anat 2016; 209:78-92. [PMID: 27773772 DOI: 10.1016/j.aanat.2016.09.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/22/2016] [Accepted: 09/25/2016] [Indexed: 01/03/2023]
Abstract
Pulmonary surfactant is a lipid-protein complex that lines and stabilizes the respiratory interface in the alveoli, allowing for gas exchange during the breathing cycle. At the same time, surfactant constitutes the first line of lung defense against pathogens. This review presents an updated view on the processes involved in biogenesis and intracellular processing of newly synthesized and recycled surfactant components, as well as on the extracellular surfactant transformations before and after the formation of the surface active film at the air-water interface. Special attention is paid to the crucial regulation of surfactant homeostasis, because its disruption is associated with several lung pathologies.
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Affiliation(s)
- Bárbara Olmeda
- Department of Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, 28040 Madrid, Spain
| | - Marta Martínez-Calle
- Department of Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, 28040 Madrid, Spain
| | - Jesus Pérez-Gil
- Department of Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, 28040 Madrid, Spain.
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30
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Cerrada A, Haller T, Cruz A, Pérez-Gil J. Pneumocytes Assemble Lung Surfactant as Highly Packed/Dehydrated States with Optimal Surface Activity. Biophys J 2016; 109:2295-306. [PMID: 26636941 DOI: 10.1016/j.bpj.2015.10.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 10/08/2015] [Accepted: 10/13/2015] [Indexed: 01/22/2023] Open
Abstract
Pulmonary surfactant (PS) is an essential complex of lipids and specific proteins synthesized in alveolar type II pneumocytes, where it is assembled and stored intracellularly as multilayered organelles known as lamellar bodies (LBs). Once secreted upon physiological stimulation, LBs maintain a densely packed structure in the form of lamellar body-like particles (LBPs), which are efficiently transferred into the alveolar air-water interface, lowering surface tension to avoid lung collapse at end-expiration. In this work, the structural organization of membranes in LBs and LBPs freshly secreted by primary cultures of rat ATII cells has been compared with that of native lung surfactant membranes isolated from porcine bronchoalveolar lavage. PS assembles in LBs as crystalline-like highly ordered structures, with a highly packed and dehydrated state, which is maintained at supraphysiological temperatures. This relatively ordered/packed state is retained in secreted LBPs. The micro- and nanostructural examination of LBPs suggests the existence of high levels of structural complexity in comparison with the material purified from lavages, which may contain partially inactivated or spent structures. Additionally, freshly secreted surfactant LBPs exhibit superior activity when generating interfacial films and a higher intrinsic resistance to inactivating agents, such as serum proteins or meconium. We propose that LBs are assembled as an energy-activated structure competent to form very efficient interfacial films, and that the organization of lipids and proteins and the properties displayed by the films formed by LBPs are likely similar to those established at the alveolar interface and represent the actual functional structure of surfactant as it sustains respiration.
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Affiliation(s)
- Alejandro Cerrada
- Department of Biochemistry, Faculty of Biology, and Hospital 12 Octubre Research Institute, Universidad Complutense, Madrid, Spain
| | - Thomas Haller
- Department of Physiology and Medical Physics, Medical University of Innsbruck, Innsbruck, Austria
| | - Antonio Cruz
- Department of Biochemistry, Faculty of Biology, and Hospital 12 Octubre Research Institute, Universidad Complutense, Madrid, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry, Faculty of Biology, and Hospital 12 Octubre Research Institute, Universidad Complutense, Madrid, Spain.
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31
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Hobi N, Giolai M, Olmeda B, Miklavc P, Felder E, Walther P, Dietl P, Frick M, Pérez-Gil J, Haller T. A small key unlocks a heavy door: The essential function of the small hydrophobic proteins SP-B and SP-C to trigger adsorption of pulmonary surfactant lamellar bodies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2124-34. [DOI: 10.1016/j.bbamcr.2016.04.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/15/2016] [Accepted: 04/27/2016] [Indexed: 02/07/2023]
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Cuesta N, Martínez A, Cuttitta F, Zudaire E. Identification of Adrenomedullin in Avian Type II Pneumocytes: Increased Expression after Exposure to Air Pollutants. J Histochem Cytochem 2016; 53:773-80. [PMID: 15928326 DOI: 10.1369/jhc.4a6498.2005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adrenomedullin (AM) is a potent vasodilator peptide present in the lung of mammals where it is expressed mainly in the columnar epithelium and alveolar macrophages. AM increases the secretion of phosphatidylcholine by type II pneumocytes, which suggests a role as an autocrine modulator of surfactant secretion. In this study we show the expression of an AM-like protein in the lung of the pigeon, Columba livia. Using an antibody against its human ortholog, AM-like immunoreactivity was found to be associated with membranous structures of the multivesicular bodies of type II pneumocytes. We also studied the differential expression of AM-like peptide in the lung of pigeons exposed to polluted city air vs cleaner countryside conditions and found that AM-like expression was higher in city animals. Similar results were obtained in an experimental study in which pigeons were exposed to increasing concentrations of a single pollutant, ozone. Taken together, our findings support the implication of AM in the response of type II pneumocytes to air pollutants.
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Affiliation(s)
- Natalia Cuesta
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA.
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Kittelberger N, Breunig M, Martin R, Knölker HJ, Miklavc P. The role of myosin 1c and myosin 1b in surfactant exocytosis. J Cell Sci 2016; 129:1685-96. [PMID: 26940917 PMCID: PMC4852769 DOI: 10.1242/jcs.181313] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/25/2016] [Indexed: 12/19/2022] Open
Abstract
Actin and actin-associated proteins have a pivotal effect on regulated exocytosis in secretory cells and influence pre-fusion as well as post-fusion stages of exocytosis. Actin polymerization on secretory granules during the post-fusion phase (formation of an actin coat) is especially important in cells with large secretory vesicles or poorly soluble secretions. Alveolar type II (ATII) cells secrete hydrophobic lipo-protein surfactant, which does not easily diffuse from fused vesicles. Previous work showed that compression of actin coat is necessary for surfactant extrusion. Here, we investigate the role of class 1 myosins as possible linkers between actin and membranes during exocytosis. Live-cell microscopy showed translocation of fluorescently labeled myosin 1b and myosin 1c to the secretory vesicle membrane after fusion. Myosin 1c translocation was dependent on its pleckstrin homology domain. Expression of myosin 1b and myosin 1c constructs influenced vesicle compression rate, whereas only the inhibition of myosin 1c reduced exocytosis. These findings suggest that class 1 myosins participate in several stages of ATII cell exocytosis and link actin coats to the secretory vesicle membrane to influence vesicle compression.
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Affiliation(s)
- Nadine Kittelberger
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
| | - Markus Breunig
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
| | - René Martin
- Department of Chemistry, Technische Universität Dresden, Bergstr. 66, Dresden 01069, Germany
| | - Hans-Joachim Knölker
- Department of Chemistry, Technische Universität Dresden, Bergstr. 66, Dresden 01069, Germany
| | - Pika Miklavc
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
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Orgeig S, Morrison JL, Daniels CB. Evolution, Development, and Function of the Pulmonary Surfactant System in Normal and Perturbed Environments. Compr Physiol 2015; 6:363-422. [PMID: 26756637 DOI: 10.1002/cphy.c150003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Surfactant lipids and proteins form a surface active film at the air-liquid interface of internal gas exchange organs, including swim bladders and lungs. The system is uniquely positioned to meet both the physical challenges associated with a dynamically changing internal air-liquid interface, and the environmental challenges associated with the foreign pathogens and particles to which the internal surface is exposed. Lungs range from simple, transparent, bag-like units to complex, multilobed, compartmentalized structures. Despite this anatomical variability, the surfactant system is remarkably conserved. Here, we discuss the evolutionary origin of the surfactant system, which likely predates lungs. We describe the evolution of surfactant structure and function in invertebrates and vertebrates. We focus on changes in lipid and protein composition and surfactant function from its antiadhesive and innate immune to its alveolar stability and structural integrity functions. We discuss the biochemical, hormonal, autonomic, and mechanical factors that regulate normal surfactant secretion in mature animals. We present an analysis of the ontogeny of surfactant development among the vertebrates and the contribution of different regulatory mechanisms that control this development. We also discuss environmental (oxygen), hormonal and biochemical (glucocorticoids and glucose) and pollutant (maternal smoking, alcohol, and common "recreational" drugs) effects that impact surfactant development. On the adult surfactant system, we focus on environmental variables including temperature, pressure, and hypoxia that have shaped its evolution and we discuss the resultant biochemical, biophysical, and cellular adaptations. Finally, we discuss the effect of major modern gaseous and particulate pollutants on the lung and surfactant system.
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Affiliation(s)
- Sandra Orgeig
- School of Pharmacy & Medical Sciences and Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Janna L Morrison
- School of Pharmacy & Medical Sciences and Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Christopher B Daniels
- School of Pharmacy & Medical Sciences and Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
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A new role for an old drug: Ambroxol triggers lysosomal exocytosis via pH-dependent Ca²⁺ release from acidic Ca²⁺ stores. Cell Calcium 2015; 58:628-37. [PMID: 26560688 DOI: 10.1016/j.ceca.2015.10.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 12/21/2022]
Abstract
Ambroxol (Ax) is a frequently prescribed drug used to facilitate mucociliary clearance, but its mode of action is yet poorly understood. Here we show by X-ray spectroscopy that Ax accumulates in lamellar bodies (LBs), the surfactant storing, secretory lysosomes of type II pneumocytes. Using lyso- and acidotropic substances in combination with fluorescence imaging we confirm that these vesicles belong to the class of acidic Ca(2+) stores. Ax lead to a significant neutralization of LB pH, followed by intracellular Ca(2+) release, and to a dose-dependent surfactant exocytosis. Ax-induced Ca(2+) release was significantly reduced and slowed down by pretreatment of the cells with bafilomycin A1 (Baf A1), an inhibitor of the vesicular H(+) ATPase. These results could be nearly reproduced with NH3/NH4(+). The findings suggest that Ax accumulates within LBs and severely affects their H(+) and Ca(2+) homeostasis. This is further supported by an Ax-induced change of nanostructural assembly of surfactant layers. We conclude that Ax profoundly affects LBs presumably by disordering lipid bilayers and by acting as a weak base. The pH change triggers - at least in part - Ca(2+) release from stores and secretion of surfactant from type II cells. This novel mechanism of Ax as a lysosomal secretagogue may also play a role for its recently discussed use for lysosomal storage and other degenerative diseases.
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Mao P, Wu S, Li J, Fu W, He W, Liu X, Slutsky AS, Zhang H, Li Y. Human alveolar epithelial type II cells in primary culture. Physiol Rep 2015; 3:e12288. [PMID: 25677546 PMCID: PMC4393197 DOI: 10.14814/phy2.12288] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 12/21/2014] [Accepted: 01/08/2015] [Indexed: 01/13/2023] Open
Abstract
Alveolar epithelial type II (AEII) cells are a key structure and defender in the lung but also are the targets in many lung diseases, including acute respiratory distress syndrome, ventilator-induced lung injury, and pulmonary fibrosis. We sought to establish an optimized method for high yielding and long maintenance of characteristics of primary human AEII cells to facilitate the investigation of the mechanisms of lung diseases at the cellular and molecular levels. Adult human peripheral normal lung tissues of oncologic patients undergoing lung resection were collected. The AEII cells were isolated and identified by the expression of pro-surfactant protein (SP)C, epithelial sodium channel (αENaC) and cytokeratin (CK)-8, the lamellar bodies specific for AEII cells, and confirmed by the histology using electron microscopy. The phenotype of AEII cells was characterized by the expression of surfactant proteins (SP-A, SP-B, SP-C, SP-D), CK-8, KL-6, αENaC, and aquaporin (AQP)-3, which was maintained over 20 days. The biological activity of the primary human AEII cells producing SP-C, cytokines, and intercellular adhesion molecule-1 was vigorous in response to stimulation with tumor necrosis factor-α. We have modified previous methods and optimized a method for isolation of high purity and long maintenance of the human AEII cell phenotype in primary culture. This method provides an important tool for studies aiming at elucidating the molecular mechanisms of lung diseases exclusively in AEII cells.
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Affiliation(s)
- Pu Mao
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
| | - Songling Wu
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
| | - Jianchun Li
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
| | - Wei Fu
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
| | - Weiqun He
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
| | - Xiaoqing Liu
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
| | - Arthur S Slutsky
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
- Keenan Research Centre for Biomedical Science of St. Michael's HospitalToronto, Ontario, Canada
- Department of Medicine, University of TorontoToronto, Ontario, Canada
| | - Haibo Zhang
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
- Keenan Research Centre for Biomedical Science of St. Michael's HospitalToronto, Ontario, Canada
- Department of Medicine, University of TorontoToronto, Ontario, Canada
- Department of Anesthesia, University of TorontoToronto, Ontario, Canada
- Department of Physiology, University of TorontoToronto, Ontario, Canada
| | - Yimin Li
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory DiseasesGuangzhou, Guangdong, China
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China
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Miklavc P, Ehinger K, Sultan A, Felder T, Paul P, Gottschalk KE, Frick M. Actin depolymerisation and crosslinking join forces with myosin II to contract actin coats on fused secretory vesicles. J Cell Sci 2015; 128:1193-203. [PMID: 25637593 PMCID: PMC4359923 DOI: 10.1242/jcs.165571] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In many secretory cells actin and myosin are specifically recruited to the surface of secretory granules following their fusion with the plasma membrane. Actomyosin-dependent compression of fused granules is essential to promote active extrusion of cargo. However, little is known about molecular mechanisms regulating actin coat formation and contraction. Here, we provide a detailed kinetic analysis of the molecules regulating actin coat contraction on fused lamellar bodies in primary alveolar type II cells. We demonstrate that ROCK1 and myosin light chain kinase 1 (MLCK1, also known as MYLK) translocate to fused lamellar bodies and activate myosin II on actin coats. However, myosin II activity is not sufficient for efficient actin coat contraction. In addition, cofilin-1 and α-actinin translocate to actin coats. ROCK1-dependent regulated actin depolymerisation by cofilin-1 in cooperation with actin crosslinking by α-actinin is essential for complete coat contraction. In summary, our data suggest a complementary role for regulated actin depolymerisation and crosslinking, and myosin II activity, to contract actin coats and drive secretion.
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Affiliation(s)
- Pika Miklavc
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Konstantin Ehinger
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Ayesha Sultan
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Tatiana Felder
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Patrick Paul
- Institute for Experimental Physics, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Kay-Eberhard Gottschalk
- Institute for Experimental Physics, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Manfred Frick
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
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Neuland K, Sharma N, Frick M. Synaptotagmin-7 links fusion-activated Ca²⁺ entry and fusion pore dilation. J Cell Sci 2014; 127:5218-27. [PMID: 25344253 PMCID: PMC4265738 DOI: 10.1242/jcs.153742] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Ca(2+)-dependent regulation of fusion pore dilation and closure is a key mechanism determining the output of cellular secretion. We have recently described 'fusion-activated' Ca(2+) entry (FACE) following exocytosis of lamellar bodies in alveolar type II cells. FACE regulates fusion pore expansion and facilitates secretion. However, the mechanisms linking this locally restricted Ca(2+) signal and fusion pore expansion were still elusive. Here, we demonstrate that synaptotagmin-7 (Syt7) is expressed on lamellar bodies and links FACE and fusion pore dilation. We directly assessed dynamic changes in fusion pore diameters by analysing diffusion of fluorophores across fusion pores. Expressing wild-type Syt7 or a mutant Syt7 with impaired Ca(2+)-binding to the C2 domains revealed that binding of Ca(2+) to the C2A domain facilitates FACE-induced pore dilation, probably by inhibiting translocation of complexin-2 to fused vesicles. However, the C2A domain hampered Ca(2+)-dependent exocytosis of lamellar bodies. These findings support the hypothesis that Syt7 modulates fusion pore expansion in large secretory organelles and extend our picture that lamellar bodies contain the necessary molecular inventory to facilitate secretion during the exocytic post-fusion phase. Moreover, regulating Syt7 levels on lamellar bodies appears to be essential in order that exocytosis is not impeded during the pre-fusion phase.
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Affiliation(s)
- Kathrin Neuland
- Institute of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Neeti Sharma
- Institute of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
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Xu J, Chai H, Ehinger K, Egan TM, Srinivasan R, Frick M, Khakh BS. Imaging P2X4 receptor subcellular distribution, trafficking, and regulation using P2X4-pHluorin. ACTA ACUST UNITED AC 2014; 144:81-104. [PMID: 24935743 PMCID: PMC4076521 DOI: 10.1085/jgp.201411169] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A P2X4 receptor labeled with the pH-sensitive GFP superecliptic pHluorin represents a useful probe to investigate P2X4 receptor distribution, trafficking, and up-regulation. P2X4 receptors are adenosine triphosphate (ATP)-gated cation channels present on the plasma membrane (PM) and also within intracellular compartments such as vesicles, vacuoles, lamellar bodies (LBs), and lysosomes. P2X4 receptors in microglia are up-regulated in epilepsy and in neuropathic pain; that is to say, their total and/or PM expression levels increase. However, the mechanisms underlying up-regulation of microglial P2X4 receptors remain unclear, in part because it has not been possible to image P2X4 receptor distribution within, or trafficking between, cellular compartments. Here, we report the generation of pH-sensitive fluorescently tagged P2X4 receptors that permit evaluations of cell surface and total receptor pools. Capitalizing on information gained from zebrafish P2X4.1 crystal structures, we designed a series of mouse P2X4 constructs in which a pH-sensitive green fluorescent protein, superecliptic pHluorin (pHluorin), was inserted into nonconserved regions located within flexible loops of the P2X4 receptor extracellular domain. One of these constructs, in which pHluorin was inserted after lysine 122 (P2X4-pHluorin123), functioned like wild-type P2X4 in terms of its peak ATP-evoked responses, macroscopic kinetics, calcium flux, current–voltage relationship, and sensitivity to ATP. P2X4-pHluorin123 also showed pH-dependent fluorescence changes, and was robustly expressed on the membrane and within intracellular compartments. P2X4-pHluorin123 identified cell surface and intracellular fractions of receptors in HEK-293 cells, hippocampal neurons, C8-B4 microglia, and alveolar type II (ATII) cells. Furthermore, it showed that the subcellular fractions of P2X4-pHluorin123 receptors were cell and compartment specific, for example, being larger in hippocampal neuron somata than in C8-B4 cell somata, and larger in C8-B4 microglial processes than in their somata. In ATII cells, P2X4-pHluorin123 showed that P2X4 receptors were secreted onto the PM when LBs undergo exocytosis. Finally, the use of P2X4-pHluorin123 showed that the modulator ivermectin did not increase the PM fraction of P2X4 receptors and acted allosterically to potentiate P2X4 receptor responses. Collectively, our data suggest that P2X4-pHluorin123 represents a useful optical probe to quantitatively explore P2X4 receptor distribution, trafficking, and up-regulation.
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Affiliation(s)
- Ji Xu
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Hua Chai
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | | | - Terrance M Egan
- Department of Pharmacological and Physiological Science and The Center for Excellence in Neuroscience, Saint Louis University School of Medicine, St. Louis, MO 63130 Department of Pharmacological and Physiological Science and The Center for Excellence in Neuroscience, Saint Louis University School of Medicine, St. Louis, MO 63130
| | - Rahul Srinivasan
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Manfred Frick
- Institute of General Physiology, University of Ulm, 89081 Ulm, Germany
| | - Baljit S Khakh
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
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Mahto SK, Tenenbaum-Katan J, Greenblum A, Rothen-Rutishauser B, Sznitman J. Microfluidic shear stress-regulated surfactant secretion in alveolar epithelial type II cells in vitro. Am J Physiol Lung Cell Mol Physiol 2014; 306:L672-83. [PMID: 24487389 DOI: 10.1152/ajplung.00106.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated the role of flow-induced shear stress on the mechanisms regulating surfactant secretion in type II alveolar epithelial cells (ATII) using microfluidic models. Following flow stimulation spanning a range of wall shear stress (WSS) magnitudes, monolayers of ATII (MLE-12 and A549) cells were examined for surfactant secretion by evaluating essential steps of the process, including relative changes in the number of fusion events of lamellar bodies (LBs) with the plasma membrane (PM) and intracellular redistribution of LBs. F-actin cytoskeleton and calcium levels were analyzed in A549 cells subjected to WSS spanning 4-20 dyn/cm(2). Results reveal an enhancement in LB fusion events with the PM in MLE-12 cells upon flow stimulation, whereas A549 cells exhibit no foreseeable changes in the monitored number of fusion events for WSS levels ranging up to a threshold of ∼8 dyn/cm(2); above this threshold, we witness instead a decrease in LB fusion events in A549 cells. However, patterns of LB redistribution suggest that WSS can potentially serve as a stimulus for A549 cells to trigger the intracellular transport of LBs toward the cell periphery. This observation is accompanied by a fragmentation of F-actin, indicating that disorganization of the F-actin cytoskeleton might act as a limiting factor for LB fusion events. Moreover, we note a rise in cytosolic calcium ([Ca(2+)]c) levels following stimulation of A549 cells with WSS magnitudes ranging near or above the experimental threshold. Overall, WSS stimulation can influence key components of molecular machinery for regulated surfactant secretion in ATII cells in vitro.
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Surfactant secretion in LRRK2 knock-out rats: changes in lamellar body morphology and rate of exocytosis. PLoS One 2014; 9:e84926. [PMID: 24465451 PMCID: PMC3897396 DOI: 10.1371/journal.pone.0084926] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 11/19/2013] [Indexed: 12/16/2022] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is known to play a role in the pathogenesis of various diseases including Parkinson disease, morbus Crohn, leprosy and cancer. LRRK2 is suggested to be involved in a number of cell biological processes such as vesicular trafficking, transcription, autophagy and lysosomal pathways. Recent histological studies of lungs of LRRK2 knock-out (LRRK2 -/-) mice revealed significantly enlarged lamellar bodies (LBs) in alveolar type II (ATII) epithelial cells. LBs are large, lysosome-related storage organelles for pulmonary surfactant, which is released into the alveolar lumen upon LB exocytosis. In this study we used high-resolution, subcellular live-cell imaging assays to investigate whether similar morphological changes can be observed in primary ATII cells from LRRK2 -/- rats and whether such changes result in altered LB exocytosis. Similarly to the report in mice, ATII cells from LRRK2 -/- rats contained significantly enlarged LBs resulting in a >50% increase in LB volume. Stimulation of ATII cells with ATP elicited LB exocytosis in a significantly increased proportion of cells from LRRK2 -/- animals. LRRK2 -/- cells also displayed increased intracellular Ca2+ release upon ATP treatment and significant triggering of LB exocytosis. These findings are in line with the strong Ca2+-dependence of LB fusion activity and suggest that LRRK2 -/- affects exocytic response in ATII cells via modulating intracellular Ca2+ signaling. Post-fusion regulation of surfactant secretion was unaltered. Actin coating of fused vesicles and subsequent vesicle compression to promote surfactant expulsion were comparable in cells from LRRK2 -/- and wt animals. Surprisingly, surfactant (phospholipid) release from LRRK2 -/- cells was reduced following stimulation of LB exocytosis possibly due to impaired LB maturation and surfactant loading of LBs. In summary our results suggest that LRRK2 -/- affects LB size, modulates intracellular Ca2+ signaling and promotes LB exocytosis upon stimulation of ATII cells with ATP.
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Cerrada A, de la Torre P, Grande J, Haller T, Flores AI, Pérez-Gil J. Human decidua-derived mesenchymal stem cells differentiate into functional alveolar type II-like cells that synthesize and secrete pulmonary surfactant complexes. PLoS One 2014; 9:e110195. [PMID: 25333871 PMCID: PMC4198213 DOI: 10.1371/journal.pone.0110195] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 09/18/2014] [Indexed: 02/05/2023] Open
Abstract
Lung alveolar type II (ATII) cells are specialized in the synthesis and secretion of pulmonary surfactant, a lipid-protein complex that reduces surface tension to minimize the work of breathing. Surfactant synthesis, assembly and secretion are closely regulated and its impairment is associated with severe respiratory disorders. At present, well-established ATII cell culture models are not available. In this work, Decidua-derived Mesenchymal Stem Cells (DMSCs) have been differentiated into Alveolar Type II- Like Cells (ATII-LCs), which display membranous cytoplasmic organelles resembling lamellar bodies, the organelles involved in surfactant storage and secretion by native ATII cells, and accumulate disaturated phospholipid species, a surfactant hallmark. Expression of characteristic ATII cells markers was demonstrated in ATII-LCs at gene and protein level. Mimicking the response of ATII cells to secretagogues, ATII-LCs were able to exocytose lipid-rich assemblies, which displayed highly surface active capabilities, including faster interfacial adsorption kinetics than standard native surfactant, even in the presence of inhibitory agents. ATII-LCs could constitute a highly useful ex vivo model for the study of surfactant biogenesis and the mechanisms involved in protein processing and lipid trafficking, as well as the packing and storage of surfactant complexes.
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Affiliation(s)
- Alejandro Cerrada
- Departmento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad Complutense, Madrid, Spain
| | - Paz de la Torre
- Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain
| | - Jesús Grande
- Departmento de Obstetricia y Ginecología, Hospital 12 de Octubre, Madrid, Spain
| | - Thomas Haller
- Department of Physiology, Innsbruck Medical University, Innsbruck, Austria
| | - Ana I. Flores
- Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain
- * E-mail: (AIF); (JPG)
| | - Jesús Pérez-Gil
- Departmento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad Complutense, Madrid, Spain
- * E-mail: (AIF); (JPG)
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Van der Velden JL, Bertoncello I, McQualter JL. LysoTracker is a marker of differentiated alveolar type II cells. Respir Res 2013; 14:123. [PMID: 24215602 PMCID: PMC3840660 DOI: 10.1186/1465-9921-14-123] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 11/06/2013] [Indexed: 01/25/2023] Open
Abstract
Background LysoTracker Green DND-26 is a fluorescent dye that stains acidic compartments in live cells and has been shown to selectively accumulate in lamellar bodies in alveolar type II (AT2) cells in the lung. The aim of this study was to determine whether the accumulation of LysoTracker in lamellar bodies can be used to isolate viable AT2 cells by flow cytometry and track their differentiation in live-cell culture by microscopy. Methods Mouse lung cells were sorted on the basis of CD45negCD31negEpCAMposLysoTrackerpos expression and characterized by immunostaining for SP-C and cultured in a three-dimensional epithelial colony-forming unit (CFU-Epi) assay. To track AT2 cell differentiation, lung epithelial stem and progenitor cells were cultured in a CFU-Epi assay with LysoTracker-supplemented media. Results The purity of sorted AT2 cells as determined by SP-C staining was 97.4% and viability was 85.3%. LysoTrackerpos AT2 cells generated SP-Cpos alveolar epithelial cell colonies in culture, and when added to the CFU-Epi culture medium, LysoTracker marked the differentiation of stem/progenitor-derived AT2 cells. Conclusions This study describes a novel method for isolating AT2 cells from mouse lungs. The high purity and viability of cells attained by this method, makes them suitable for functional analysis in vitro. The application of LysoTracker to live cell cultures will allow better assessment of the cellular and molecular mechanisms that regulate AT2 cell differentiation.
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Affiliation(s)
| | | | - Jonathan L McQualter
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Victoria, Australia.
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Bouzas V, Haller T, Hobi N, Felder E, Pastoriza-Santos I, Pérez-Gil J. Nontoxic impact of PEG-coated gold nanospheres on functional pulmonary surfactant-secreting alveolar type II cells. Nanotoxicology 2013; 8:813-23. [PMID: 23914786 DOI: 10.3109/17435390.2013.829878] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The outstanding properties of gold nanoparticles (NPs) make them very attractive for biomedical applications. In particular, the inhalation route has gained considerable interest as an innovative strategy for diagnosis and treatment of pulmonary diseases. It is, therefore, important to scrutinise the potentially deleterious or side effects of NPs on lung epithelium. The present study investigates, for the first time, the impact of polyethylene glycol (PEG)-coated NPs on freshly purified primary cultures of rat alveolar type II (ATII) cells. These cells play a central role in the respiratory function of the lungs. They are responsible for synthesizing and secreting pulmonary surfactant (PS), which is required to stabilise the respiratory surface during breathing dynamics. Cytotoxicity and cellular uptake of NPs was evaluated by analysing morphology, viability and exocytotic activity of ATII cells (PS secretion). The impact of ATII cells' exposure to NPs was studied in a wide range of gold concentration with particles sizes of 15 and 100 nm. The results show that PEG-coated NPs are very modestly internalised by ATII cells and it neither leads to detectable morphological changes nor to decreased cell viability nor to alterations in basic functional parameters such as PS secretion, even on exposure to high gold concentration (~0.2 mM) during relatively long periods of time (24-48 h).
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Affiliation(s)
- Virginia Bouzas
- Departamento de Bioquímica y Biología Molecular I, Facultad de Biología, Universidad Complutense , Madrid , Spain
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Pulmonary surfactant preserves viability of alveolar type II cells exposed to polymyxin B in vitro. PLoS One 2013; 8:e62105. [PMID: 23620808 PMCID: PMC3631157 DOI: 10.1371/journal.pone.0062105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/18/2013] [Indexed: 01/23/2023] Open
Abstract
Background Exogenous surfactant derived from animal lungs is applied for treatment of surfactant deficiency. By means of its rapid spreading properties, it could transport pharmaceutical agents to the terminal air spaces. The antimicrobial peptide Polymyxin B (PxB) is used as a topical antibiotic for inhalation therapy. Whereas it has been shown that PxB mixed with surfactant is not inhibiting surface activity while antimicrobiotic activity is preserved, little is known concerning the effects on synthesis of endogenous surfactant in alveolar type II cells (ATIIC). Objective To investigate ATIIC viability and surfactant-exocytosis depending on PxB and/or surfactant exposure. Methods ATIIC were isolated from rat lungs as previously described and were cultivated for 48 h. After incubation for a period of 1–5 h with either PxB (0.05 or 0.1 mg/ml), modified porcine surfactant (5 or 10 mg/ml) or mixtures of both, viability and exocytosis (spontanously and after stimulation) were determined by fluorescence staining of intracellular surfactant. Results PxB 0.1 mg/ml, but not porcine surfactant or porcine surfactant plus PxB reduces ATIIC-viability. Only PxB alone, but not in combination with porcine surfactant, rapidly reduces fluorescence in ATIIC at maximum within 3 h, indicating stimulation of exocytosis. Subsequent ionomycin-stimulation does not further increase exocytosis of PxB incubated ATIIC. In presence of surfactant, stimulating effects of PxB and ionomycin on exocytosis are reduced. Conclusion PxB alone shows negative effects on ATIIC, which are counterbalanced in mixtures with surfactant. So far, our studies found no results discouraging the concept of a combined treatment with PxB and surfactant mixtures.
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Thompson KE, Korbmacher JP, Hecht E, Hobi N, Wittekindt OH, Dietl P, Kranz C, Frick M. Fusion-activated cation entry (FACE) via P2X₄ couples surfactant secretion and alveolar fluid transport. FASEB J 2013; 27:1772-83. [PMID: 23307836 DOI: 10.1096/fj.12-220533] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Two fundamental mechanisms within alveoli are essential for lung function: regulated fluid transport and secretion of surfactant. Surfactant is secreted via exocytosis of lamellar bodies (LBs) in alveolar type II (ATII) cells. We recently reported that LB exocytosis results in fusion-activated cation entry (FACE) via P2X₄ receptors on LBs. We propose that FACE, in addition to facilitating surfactant secretion, modulates alveolar fluid transport. Correlative fluorescence and atomic force microscopy revealed that FACE-dependent water influx correlated with individual fusion events in rat primary ATII cells. Moreover, ATII cell monolayers grown at air-liquid interface exhibited increases in short-circuit current (Isc) on stimulation with ATP or UTP. Both are potent agonists for LB exocytosis, but only ATP activates FACE. ATP, not UTP, elicited additional fusion-dependent increases in Isc. Overexpressing dominant-negative P2X₄ abrogated this effect by ∼50%, whereas potentiating P2X4 lead to ∼80% increase in Isc. Finally, we monitored changes in alveolar surface liquid (ASL) on ATII monolayers by confocal microscopy. Only stimulation with ATP, not UTP, led to a significant, fusion-dependent, 20% decrease in ASL, indicating apical-to-basolateral fluid transport across ATII monolayers. Our data support the first direct link between LB exocytosis, regulation of surfactant secretion, and transalveolar fluid resorption via FACE.
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Impairment of alveolar type-II cells involved in the toxicity of Aflatoxin G1 in rat lung. Food Chem Toxicol 2012; 50:3222-8. [DOI: 10.1016/j.fct.2012.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 11/18/2022]
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Hecht E, Thompson K, Frick M, Wittekindt OH, Dietl P, Mizaikoff B, Kranz C. Combined atomic force microscopy-fluorescence microscopy: analyzing exocytosis in alveolar type II cells. Anal Chem 2012; 84:5716-22. [PMID: 22694258 DOI: 10.1021/ac300775j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hybrid atomic force microscopy (AFM)-fluorescence microscopy (FM) investigation of exocytosis in lung epithelial cells (ATII cells) allows the detection of individual exocytic events by FM, which can be simultaneously correlated to structural changes in individual cells by AFM. Exocytosis of lamellar bodies (LBs) represents a slow form of exocytosis found in many non-neuronal cells. Exocytosis of LBs, following stimulation with adenosine-5'-triphosphate (ATP) and phorbol 12-myristate 13-acetate (PMA), results in a cation influx via P2X(4) receptors at the site of LB fusion with the plasma membrane (PM), which should induce a temporary increase in cell height/volume. AFM measurements were performed in single-line scans across the cell surface. Five minutes after stimulation, ATII cells revealed a cell height and volume increase of 13.7% ± 4.1% and 15.9 ± 4.8% (N = 9), respectively. These transient changes depend on exocytic LB-PM fusion. Nonstimulated cells and cells lacking LB fusions did not show a significant change in cell height/volume (N = 8). In addition, a cell height decrease was observed in ATII cells stimulated by uridine-5'-triphosphate (UTP) and PMA, agonists inducing LB fusion with the PM, but not activation of P2X(4) receptors. The cell height and volume decreased by -8.6 ± 3.6% and -11.2 ± 3.9% (N = 5), respectively. Additionally, low force contact and dynamic mode AFM imaging of cell areas around the nucleus after stimulation with ATP/PMA was performed. Fused LBs are more pronounced in AFM topography images compared to nonfused LBs, concluding that different "dynamic states" of LBs or locations from the PM are captured during imaging.
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Affiliation(s)
- Elena Hecht
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany
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Hobi N, Ravasio A, Haller T. Interfacial stress affects rat alveolar type II cell signaling and gene expression. Am J Physiol Lung Cell Mol Physiol 2012; 303:L117-29. [PMID: 22610352 DOI: 10.1152/ajplung.00340.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous work from our group (Ravasio A, Hobi N, Bertocchi C, Jesacher A, Dietl P, Haller T. Am J Physiol Cell Physiol 300: C1456-C1465, 2011.) showed that contact of alveolar epithelial type II cells with an air-liquid interface (I(AL)) leads to a paradoxical situation. It is a potential threat that can cause cell injury, but also a Ca(2+)-dependent stimulus for surfactant secretion. Both events can be explained by the impact of interfacial tensile forces on cellular structures. Here, the strength of this mechanical stimulus became also apparent in microarray studies by a rapid and significant change on the transcriptional level. Cells challenged with an I(AL) in two different ways showed activation/inactivation of cellular pathways involved in stress response and defense, and a detailed Pubmatrix search identified genes associated with several lung diseases and injuries. Altogether, they suggest a close relationship of interfacial stress sensation with current models in alveolar micromechanics. Further similarities between I(AL) and cell stretch were found with respect to the underlying signaling events. The source of Ca(2+) was extracellular, and the transmembrane Ca(2+) entry pathway suggests the involvement of a mechanosensitive channel. We conclude that alveolar type II cells, due to their location and morphology, are specific sensors of the I(AL), but largely protected from interfacial stress by surfactant release.
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Affiliation(s)
- Nina Hobi
- Department of Physiology and Medical Physics, Division of Physiology, Innsbruck Medical University, Austria
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Dietl P, Haller T, Frick M. Spatio-temporal aspects, pathways and actions of Ca(2+) in surfactant secreting pulmonary alveolar type II pneumocytes. Cell Calcium 2012; 52:296-302. [PMID: 22591642 DOI: 10.1016/j.ceca.2012.04.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 04/11/2012] [Accepted: 04/18/2012] [Indexed: 01/16/2023]
Abstract
The type II cell of the pulmonary alveolus is a polarized epithelial cell that secretes surfactant into the alveolar space by regulated exocytosis of lamellar bodies (LBs). This process consists of multiple sequential steps and is correlated to elevations of the cytoplasmic Ca(2+) concentration ([Ca(2+)](c)) required for extended periods of secretory activity. Both chemical (purinergic) and mechanical (cell stretch or exposure to an air-liquid interface) stimuli give rise to complex Ca(2+) signals (such as Ca(2+) peaks, spikes and plateaus) that differ in shape, origin and spatio-temporal behavior. This review summarizes current knowledge about Ca(2+) channels, including vesicular P2X4 purinoceptors, in type II cells and associated signaling cascades within the alveolar microenvironment, and relates stimulus-dependent activation of these pathways with distinct stages of surfactant secretion, including pre- and postfusion stages of LB exocytosis.
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Affiliation(s)
- Paul Dietl
- Institute of General Physiology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
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