1
|
Struckman HL, Moise N, Vanslembrouck B, Rothacker N, Chen Z, van Hengel J, Weinberg SH, Veeraraghavan R. Indirect Correlative Light and Electron Microscopy (iCLEM): A Novel Pipeline for Multiscale Quantification of Structure From Molecules to Organs. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2024; 30:318-333. [PMID: 38525890 PMCID: PMC11057817 DOI: 10.1093/mam/ozae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 12/09/2023] [Accepted: 02/26/2024] [Indexed: 03/26/2024]
Abstract
Correlative light and electron microscopy (CLEM) methods are powerful methods that combine molecular organization (from light microscopy) with ultrastructure (from electron microscopy). However, CLEM methods pose high cost/difficulty barriers to entry and have very low experimental throughput. Therefore, we have developed an indirect correlative light and electron microscopy (iCLEM) pipeline to sidestep the rate-limiting steps of CLEM (i.e., preparing and imaging the same samples on multiple microscopes) and correlate multiscale structural data gleaned from separate samples imaged using different modalities by exploiting biological structures identifiable by both light and electron microscopy as intrinsic fiducials. We demonstrate here an application of iCLEM, where we utilized gap junctions and mechanical junctions between muscle cells in the heart as intrinsic fiducials to correlate ultrastructural measurements from transmission electron microscopy (TEM), and focused ion beam scanning electron microscopy (FIB-SEM) with molecular organization from confocal microscopy and single molecule localization microscopy (SMLM). We further demonstrate how iCLEM can be integrated with computational modeling to discover structure-function relationships. Thus, we present iCLEM as a novel approach that complements existing CLEM methods and provides a generalizable framework that can be applied to any set of imaging modalities, provided suitable intrinsic fiducials can be identified.
Collapse
Affiliation(s)
- Heather L Struckman
- Department of Biomedical Engineering, College of Engineering, 2124 Fontana Labs, 140 W. 19th Ave, The Ohio State University, Columbus, OH 43210, USA
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, 2255 Kenny Rd, Rm 5189, Pelotonia Research Center, Columbus, OH 43210, USA
| | - Nicolae Moise
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, 2255 Kenny Rd, Rm 5189, Pelotonia Research Center, Columbus, OH 43210, USA
| | - Bieke Vanslembrouck
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA
- Medical Cell Biology Research Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Corneel Heymanslaan 10, Building B, Entrance 36, 9000 Ghent, Belgium
| | - Nathan Rothacker
- Department of Biomedical Engineering, College of Engineering, 2124 Fontana Labs, 140 W. 19th Ave, The Ohio State University, Columbus, OH 43210, USA
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, 2255 Kenny Rd, Rm 5189, Pelotonia Research Center, Columbus, OH 43210, USA
| | - Zhenhui Chen
- Krannert Cardiovascular Research Center, Department of Medicine, Indiana University, Room E400, 1801 N. Senate Blvd., Suite E400, Indianapolis, IN 46202, USA
| | - Jolanda van Hengel
- Medical Cell Biology Research Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Corneel Heymanslaan 10, Building B, Entrance 36, 9000 Ghent, Belgium
| | - Seth H Weinberg
- Department of Biomedical Engineering, College of Engineering, 2124 Fontana Labs, 140 W. 19th Ave, The Ohio State University, Columbus, OH 43210, USA
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, 2255 Kenny Rd, Rm 5189, Pelotonia Research Center, Columbus, OH 43210, USA
| | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, College of Engineering, 2124 Fontana Labs, 140 W. 19th Ave, The Ohio State University, Columbus, OH 43210, USA
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, 2255 Kenny Rd, Rm 5189, Pelotonia Research Center, Columbus, OH 43210, USA
| |
Collapse
|
2
|
Al-Rekabi Z, Dondi C, Faruqui N, Siddiqui NS, Elowsson L, Rissler J, Kåredal M, Mudway I, Larsson-Callerfelt AK, Shaw M. Uncovering the cytotoxic effects of air pollution with multi-modal imaging of in vitro respiratory models. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221426. [PMID: 37063998 PMCID: PMC10090883 DOI: 10.1098/rsos.221426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
Annually, an estimated seven million deaths are linked to exposure to airborne pollutants. Despite extensive epidemiological evidence supporting clear associations between poor air quality and a range of short- and long-term health effects, there are considerable gaps in our understanding of the specific mechanisms by which pollutant exposure induces adverse biological responses at the cellular and tissue levels. The development of more complex, predictive, in vitro respiratory models, including two- and three-dimensional cell cultures, spheroids, organoids and tissue cultures, along with more realistic aerosol exposure systems, offers new opportunities to investigate the cytotoxic effects of airborne particulates under controlled laboratory conditions. Parallel advances in high-resolution microscopy have resulted in a range of in vitro imaging tools capable of visualizing and analysing biological systems across unprecedented scales of length, time and complexity. This article considers state-of-the-art in vitro respiratory models and aerosol exposure systems and how they can be interrogated using high-resolution microscopy techniques to investigate cell-pollutant interactions, from the uptake and trafficking of particles to structural and functional modification of subcellular organelles and cells. These data can provide a mechanistic basis from which to advance our understanding of the health effects of airborne particulate pollution and develop improved mitigation measures.
Collapse
Affiliation(s)
- Zeinab Al-Rekabi
- Department of Chemical and Biological Sciences, National Physical Laboratory, Teddington, UK
| | - Camilla Dondi
- Department of Chemical and Biological Sciences, National Physical Laboratory, Teddington, UK
| | - Nilofar Faruqui
- Department of Chemical and Biological Sciences, National Physical Laboratory, Teddington, UK
| | - Nazia S. Siddiqui
- Faculty of Medical Sciences, University College London, London, UK
- Kingston Hospital NHS Foundation Trust, Kingston upon Thames, UK
| | - Linda Elowsson
- Lung Biology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Jenny Rissler
- Bioeconomy and Health, RISE Research Institutes of Sweden, Lund, Sweden
- Ergonomics and Aerosol Technology, Lund University, Lund, Sweden
| | - Monica Kåredal
- Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Ian Mudway
- MRC Centre for Environment and Health, Imperial College London, London, UK
- National Institute of Health Protection Research Unit in Environmental Exposures and Health, London, UK
- Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
| | | | - Michael Shaw
- Department of Chemical and Biological Sciences, National Physical Laboratory, Teddington, UK
- Department of Computer Science, University College London, London, UK
| |
Collapse
|
3
|
Peddie CJ, Genoud C, Kreshuk A, Meechan K, Micheva KD, Narayan K, Pape C, Parton RG, Schieber NL, Schwab Y, Titze B, Verkade P, Aubrey A, Collinson LM. Volume electron microscopy. NATURE REVIEWS. METHODS PRIMERS 2022; 2:51. [PMID: 37409324 PMCID: PMC7614724 DOI: 10.1038/s43586-022-00131-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/10/2022] [Indexed: 07/07/2023]
Abstract
Life exists in three dimensions, but until the turn of the century most electron microscopy methods provided only 2D image data. Recently, electron microscopy techniques capable of delving deep into the structure of cells and tissues have emerged, collectively called volume electron microscopy (vEM). Developments in vEM have been dubbed a quiet revolution as the field evolved from established transmission and scanning electron microscopy techniques, so early publications largely focused on the bioscience applications rather than the underlying technological breakthroughs. However, with an explosion in the uptake of vEM across the biosciences and fast-paced advances in volume, resolution, throughput and ease of use, it is timely to introduce the field to new audiences. In this Primer, we introduce the different vEM imaging modalities, the specialized sample processing and image analysis pipelines that accompany each modality and the types of information revealed in the data. We showcase key applications in the biosciences where vEM has helped make breakthrough discoveries and consider limitations and future directions. We aim to show new users how vEM can support discovery science in their own research fields and inspire broader uptake of the technology, finally allowing its full adoption into mainstream biological imaging.
Collapse
Affiliation(s)
- Christopher J. Peddie
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, UK
| | - Christel Genoud
- Electron Microscopy Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Anna Kreshuk
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Kimberly Meechan
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Present address: Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Kristina D. Micheva
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, CA, USA
| | - Kedar Narayan
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Constantin Pape
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Robert G. Parton
- The Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia
| | - Nicole L. Schieber
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia
| | - Yannick Schwab
- Cell Biology and Biophysics Unit/ Electron Microscopy Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | | | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol, UK
| | - Aubrey Aubrey
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Lucy M. Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, UK
| |
Collapse
|
4
|
Marlow J, Spietz R, Kim K, Ellisman M, Girguis P, Hatzenpichler R. Spatially resolved correlative microscopy and microbial identification reveal dynamic depth- and mineral-dependent anabolic activity in salt marsh sediment. Environ Microbiol 2021; 23:4756-4777. [PMID: 34346142 PMCID: PMC8456820 DOI: 10.1111/1462-2920.15667] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 07/08/2021] [Indexed: 01/04/2023]
Abstract
Coastal salt marshes are key sites of biogeochemical cycling and ideal systems in which to investigate the community structure of complex microbial communities. Here, we clarify structural-functional relationships among microorganisms and their mineralogical environment, revealing previously undescribed metabolic activity patterns and precise spatial arrangements within salt marsh sediment. Following 3.7-day in situ incubations with a non-canonical amino acid that was incorporated into new biomass, samples were resin-embedded and analysed by correlative fluorescence and electron microscopy to map the microscale arrangements of anabolically active and inactive organisms alongside mineral grains. Parallel sediment samples were examined by fluorescence-activated cell sorting and 16S rRNA gene sequencing to link anabolic activity to taxonomic identity. Both approaches demonstrated a rapid decline in the proportion of anabolically active cells with depth into salt marsh sediment, from ~60% in the top centimetre to 9.4%-22.4% between 2 and 10 cm. From the top to the bottom, the most prominent active community members shifted from sulfur cycling phototrophic consortia, to putative sulfate-reducing bacteria likely oxidizing organic compounds, to fermentative lineages. Correlative microscopy revealed more abundant (and more anabolically active) organisms around non-quartz minerals including rutile, orthoclase and plagioclase. Microbe-mineral relationships appear to be dynamic and context-dependent arbiters of biogeochemical cycling.
Collapse
Affiliation(s)
- Jeffrey Marlow
- Department of Organismic and Evolutionary BiologyHarvard University16 Divinity AveCambridgeMassachusetts02138USA
| | - Rachel Spietz
- Department of Chemistry and Biochemistry, Department of Microbiology and Cell Biology, Thermal Biology Institute, and Center for Biofilm EngineeringMontana State UniversityBozemanMontana59717USA
| | - Keun‐Young Kim
- Department of NeurosciencesUniversity of California at San Diego School of Medicine and National Center for Microscopy and Imaging Research, University of CaliforniaSan DiegoLa JollaCalifornia92093USA
| | - Mark Ellisman
- Department of NeurosciencesUniversity of California at San Diego School of Medicine and National Center for Microscopy and Imaging Research, University of CaliforniaSan DiegoLa JollaCalifornia92093USA
- Department of PharmacologyUniversity of CaliforniaSan DiegoLa JollaCalifornia92161USA
| | - Peter Girguis
- Department of Organismic and Evolutionary BiologyHarvard University16 Divinity AveCambridgeMassachusetts02138USA
| | - Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Department of Microbiology and Cell Biology, Thermal Biology Institute, and Center for Biofilm EngineeringMontana State UniversityBozemanMontana59717USA
| |
Collapse
|
5
|
Tanner H, Hodgson L, Mantell J, Verkade P. Fluorescent platinum nanoclusters as correlative light electron microscopy probes. Methods Cell Biol 2021; 162:39-68. [PMID: 33707021 DOI: 10.1016/bs.mcb.2020.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Correlative Imaging (CI) visualizes a single sample/region of interest with two or more imaging modalities. The technique seeks to elucidate information that may not be discernible by using either of the constituent techniques in isolation. Correlative Light Electron Microscopy (CLEM) can be employed to streamline workflows, i.e., using fluorescent signals in the light microscope (LM) to inform the user of regions which should be imaged with electron microscopy (EM). The efficacy of correlative techniques requires high spatial resolution of signals from both imaging modalities. Ideally, a single point should originate from both the fluorescence and electron density. However, many of the ubiquitously used probes have a significant distance between their fluorescence and electron dense portions. Furthermore, electron dense metal nanoparticles used for EM visualization readily quench any proximal adjacent fluorophores. Therefore, accurate registration of both signals becomes difficult. Here we describe fluorescent nanoclusters in the context of a CLEM probe as they are composed of several atoms of a noble metal, in this case platinum, providing electron density. In addition, their structure confers them with fluorescence via a mechanism analogous to quantum dots. The electron dense core gives rise to the fluorescence which enables highly accurate signal registration between epifluorescence and electron imaging modalities. We provide a protocol for the synthesis of the nanoclusters with some additional techniques for their characterization and finally show how they can be used in a CLEM set up.
Collapse
Affiliation(s)
- Hugh Tanner
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Lorna Hodgson
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Paul Verkade
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom.
| |
Collapse
|
6
|
Abstract
Since its entry into biomedical research in the first half of the twentieth century, electron microscopy has been a valuable tool for lung researchers to explore the lung's delicate ultrastructure. Among others, it proved the existence of a continuous alveolar epithelium and demonstrated the surfactant lining layer. With the establishment of serial sectioning transmission electron microscopy, as the first "volume electron microscopic" technique, electron microscopy entered the third dimension and investigations of the lung's three-dimensional ultrastructure became possible. Over the years, further techniques, ranging from electron tomography over serial block-face and focused ion beam scanning electron microscopy to array tomography became available. All techniques cover different volumes and resolutions, and, thus, different scientific questions. This review gives an overview of these techniques and their application in lung research, focusing on their fields of application and practical implementation. Furthermore, an introduction is given how the output raw data are processed and the final three-dimensional models can be generated.
Collapse
Affiliation(s)
- Jan Philipp Schneider
- Institute of Functional and Applied Anatomy, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), 30625 Hannover, Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), 30625 Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, 30625 Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, 30625 Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), 30625 Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, 30625 Hannover, Germany
| |
Collapse
|
7
|
Mühlfeld C, Wrede C, Molnár V, Rajces A, Brandenberger C. The plate body: 3D ultrastructure of a facultative organelle of alveolar epithelial type II cells involved in SP-A trafficking. Histochem Cell Biol 2021; 155:261-269. [PMID: 32880000 PMCID: PMC7910259 DOI: 10.1007/s00418-020-01912-7] [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] [Accepted: 08/21/2020] [Indexed: 12/14/2022]
Abstract
Plate bodies are facultative organelles occasionally described in the adult lungs of various species, including sheep and goat. They consist of multiple layers of plate-like cisterns with an electron dense middle bar. The present study was performed to elucidate the three-dimensional (3D) characteristics of this organelle and its presumed function in surfactant protein A (SP-A) biology. Archived material of four adult goat lungs and PFA-fixed lung samples of two adult sheep lungs were used for the morphological and immunocytochemical parts of this study, respectively. 3D imaging was performed by electron tomography and focused ion beam scanning electron microscopy (FIB-SEM). Immuno gold labeling was used to analyze whether plate bodies are positive for SP-A. Transmission electron microscopy revealed the presence of plate bodies in three of four goat lungs and in both sheep lungs. Electron tomography and FIB-SEM characterized the plate bodies as layers of two up to over ten layers of membranous cisterns with the characteristic electron dense middle bar. The membranes of the plates were in connection with the rough endoplasmic reticulum and showed vesicular inclusions in the middle of the plates and a vesicular network at the sides of the organelle. Immuno gold labeling revealed the presence of SP-A in the vesicular network of plate bodies but not in the characteristic plates themselves. In conclusion, the present study clearly proves the connection of plate bodies with the rough endoplasmic reticulum and the presence of a vesicular network as part of the organelle involved in SP-A trafficking.
Collapse
Affiliation(s)
- Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, 30625, Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, 30625, Hannover, Germany
| | | | - Alexandra Rajces
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Christina Brandenberger
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
- Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany.
| |
Collapse
|
8
|
Ochs M, Hegermann J, Lopez-Rodriguez E, Timm S, Nouailles G, Matuszak J, Simmons S, Witzenrath M, Kuebler WM. On Top of the Alveolar Epithelium: Surfactant and the Glycocalyx. Int J Mol Sci 2020; 21:ijms21093075. [PMID: 32349261 PMCID: PMC7246550 DOI: 10.3390/ijms21093075] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 12/14/2022] Open
Abstract
Gas exchange in the lung takes place via the air-blood barrier in the septal walls of alveoli. The tissue elements that oxygen molecules have to cross are the alveolar epithelium, the interstitium and the capillary endothelium. The epithelium that lines the alveolar surface is covered by a thin and continuous liquid lining layer. Pulmonary surfactant acts at this air-liquid interface. By virtue of its biophysical and immunomodulatory functions, surfactant keeps alveoli open, dry and clean. What needs to be added to this picture is the glycocalyx of the alveolar epithelium. Here, we briefly review what is known about this glycocalyx and how it can be visualized using electron microscopy. The application of colloidal thorium dioxide as a staining agent reveals differences in the staining pattern between type I and type II alveolar epithelial cells and shows close associations of the glycocalyx with intraalveolar surfactant subtypes such as tubular myelin. These morphological findings indicate that specific spatial interactions between components of the surfactant system and those of the alveolar epithelial glycocalyx exist which may contribute to the maintenance of alveolar homeostasis, in particular to alveolar micromechanics, to the functional integrity of the air-blood barrier, to the regulation of the thickness and viscosity of the alveolar lining layer, and to the defence against inhaled pathogens. Exploring the alveolar epithelial glycocalyx in conjunction with the surfactant system opens novel physiological perspectives of potential clinical relevance for future research.
Collapse
Affiliation(s)
- Matthias Ochs
- Institute of Functional Anatomy, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
- German Center for Lung Research (DZL), 10117 Berlin, Germany; (M.W.); (W.M.K.)
- Correspondence:
| | - Jan Hegermann
- Research Core Unit Electron Microscopy and Institute of Functional and Applied Anatomy, Hannover Medical School, 30625 Hannover, Germany;
| | - Elena Lopez-Rodriguez
- Institute of Functional Anatomy, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
| | - Sara Timm
- Core Facility Electron Microscopy, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
| | - Geraldine Nouailles
- Department of Infectious Diseases and Respiratory Medicine, and Division of Pulmonary Inflammation, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
| | - Jasmin Matuszak
- Institute of Physiology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany; (J.M.); (S.S.)
| | - Szandor Simmons
- Institute of Physiology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany; (J.M.); (S.S.)
| | - Martin Witzenrath
- German Center for Lung Research (DZL), 10117 Berlin, Germany; (M.W.); (W.M.K.)
- Department of Infectious Diseases and Respiratory Medicine, and Division of Pulmonary Inflammation, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
| | - Wolfgang M. Kuebler
- German Center for Lung Research (DZL), 10117 Berlin, Germany; (M.W.); (W.M.K.)
- Institute of Physiology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany; (J.M.); (S.S.)
| |
Collapse
|
9
|
Schneider JP, Wrede C, Mühlfeld C. The Three-Dimensional Ultrastructure of the Human Alveolar Epithelium Revealed by Focused Ion Beam Electron Microscopy. Int J Mol Sci 2020; 21:ijms21031089. [PMID: 32041332 PMCID: PMC7038159 DOI: 10.3390/ijms21031089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/22/2020] [Accepted: 01/30/2020] [Indexed: 12/12/2022] Open
Abstract
Thin type 1 alveolar epithelial (AE1) and surfactant producing type 2 alveolar epithelial (AE2) cells line the alveoli in the lung and are essential for normal lung function. Function is intimately interrelated to structure, so that detailed knowledge of the epithelial ultrastructure can significantly enhance our understanding of its function. The basolateral surface of the cells or the epithelial contact sites are of special interest, because they play an important role in intercellular communication or stabilizing the epithelium. The latter is in particular important for the lung with its variable volume. The aim of the present study was to investigate the three-dimensional (3D) ultrastructure of the human alveolar epithelium focusing on contact sites and the basolateral cell membrane of AE2 cells using focused ion beam electron microscopy and subsequent 3D reconstructions. The study provides detailed surface reconstructions of two AE1 cell domains and two AE2 cells, showing AE1/AE1, AE1/AE2 and AE2/AE2 contact sites, basolateral microvilli pits at AE2 cells and small AE1 processes beneath AE2 cells. Furthermore, we show reconstructions of a surfactant secretion pore, enlargements of the apical AE1 cell surface and long folds bordering grooves on the basal AE1 cell surface. The functional implications of our findings are discussed. These findings may lay the structural basis for further molecular investigations.
Collapse
Affiliation(s)
- Jan Philipp Schneider
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany; (C.W.); (C.M.)
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
- Correspondence:
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany; (C.W.); (C.M.)
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany; (C.W.); (C.M.)
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| |
Collapse
|