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Albers J, Wagner WL, Fiedler MO, Rothermel A, Wünnemann F, Di Lillo F, Dreossi D, Sodini N, Baratella E, Confalonieri M, Arfelli F, Kalenka A, Lotz J, Biederer J, Wielpütz MO, Kauczor HU, Alves F, Tromba G, Dullin C. High resolution propagation-based lung imaging at clinically relevant X-ray dose levels. Sci Rep 2023; 13:4788. [PMID: 36959233 PMCID: PMC10036329 DOI: 10.1038/s41598-023-30870-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/02/2023] [Indexed: 03/25/2023] Open
Abstract
Absorption-based clinical computed tomography (CT) is the current imaging method of choice in the diagnosis of lung diseases. Many pulmonary diseases are affecting microscopic structures of the lung, such as terminal bronchi, alveolar spaces, sublobular blood vessels or the pulmonary interstitial tissue. As spatial resolution in CT is limited by the clinically acceptable applied X-ray dose, a comprehensive diagnosis of conditions such as interstitial lung disease, idiopathic pulmonary fibrosis or the characterization of small pulmonary nodules is limited and may require additional validation by invasive lung biopsies. Propagation-based imaging (PBI) is a phase sensitive X-ray imaging technique capable of reaching high spatial resolutions at relatively low applied radiation dose levels. In this publication, we present technical refinements of PBI for the characterization of different artificial lung pathologies, mimicking clinically relevant patterns in ventilated fresh porcine lungs in a human-scale chest phantom. The combination of a very large propagation distance of 10.7 m and a photon counting detector with [Formula: see text] pixel size enabled high resolution PBI CT with significantly improved dose efficiency, measured by thermoluminescence detectors. Image quality was directly compared with state-of-the-art clinical CT. PBI with increased propagation distance was found to provide improved image quality at the same or even lower X-ray dose levels than clinical CT. By combining PBI with iodine k-edge subtraction imaging we further demonstrate that, the high quality of the calculated iodine concentration maps might be a potential tool for the analysis of lung perfusion in great detail. Our results indicate PBI to be of great value for accurate diagnosis of lung disease in patients as it allows to depict pathological lesions non-invasively at high resolution in 3D. This will especially benefit patients at high risk of complications from invasive lung biopsies such as in the setting of suspected idiopathic pulmonary fibrosis (IPF).
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Affiliation(s)
- Jonas Albers
- Department for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany
- Biological X-ray imaging, European Molecular Biology Laboratory, Hamburg Unit c/o DESY, Hamburg, Germany
| | - Willi L Wagner
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
| | - Mascha O Fiedler
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
- Department of Anaesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Anne Rothermel
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
| | - Felix Wünnemann
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
| | | | - Diego Dreossi
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Nicola Sodini
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Elisa Baratella
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | | | - Fulvia Arfelli
- Department of Physics, University of Trieste and INFN, Trieste, Italy
| | - Armin Kalenka
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
- Department of Anaesthesiology and Intensive Care Medicine, District Hospital Bergstrasse, Heppenheim, Germany
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Joachim Lotz
- Department for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany
| | - Jürgen Biederer
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
- Faculty of Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Faculty of Medicine, University of Latvia, Riga, Latvia
| | - Mark O Wielpütz
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
| | - Hans-Ulrich Kauczor
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany
| | - Frauke Alves
- Department for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany
- Department for Haematology and Medical Oncology, University Medical Center Goettingen, Goettingen, Germany
- Translational Molecular Imaging, Max-Plank-Institute for Multidisciplinary Sciences, Goettingen, Germany
| | | | - Christian Dullin
- Department for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany.
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), University Heidelberg, Heidelberg, Germany.
- Translational Molecular Imaging, Max-Plank-Institute for Multidisciplinary Sciences, Goettingen, Germany.
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Rothermel A, Kaim H, Gambach S, Schuetz H, Moll S, Steinhoff R, Herrmann T, Zeck G. Subretinal Stimulation Chip Set with 3025 Electrodes, Spatial Peaking Filter, Illumination Adaptation and Implant Lifetime Optimization. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2020:4310-4313. [PMID: 33018949 DOI: 10.1109/embc44109.2020.9175722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A subretinal stimulator chip has been designed and tested, which combines high pixel number with highest simulation voltages, lowest power consumption, spatial peaking and illumination adaptation. A supporting ASIC completes the implantable device electronics. Blind mouse retina has successfully been stimulated in vitro.
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Wagner WL, Rothermel A, Mokry T, Sommerer C, Heußel CP, Kauczor HU. [Rare cause for acute chest pain and dyspnea in young men]. Med Klin Intensivmed Notfmed 2019; 114:342-344. [PMID: 30840095 DOI: 10.1007/s00063-019-0534-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/09/2018] [Accepted: 12/13/2018] [Indexed: 10/27/2022]
Affiliation(s)
- W L Wagner
- Klinik für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Deutschland. .,Translational Lung Research Center Heidelberg (TLRC) Member of the German Center for Lung Research (DZL), Universitätsklinikum Heidelberg, Heidelberg, Deutschland.
| | - A Rothermel
- Klinik für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Deutschland
| | - T Mokry
- Klinik für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Deutschland
| | - C Sommerer
- Sektion Nephrologie, Universitätsklinikum Heidelberg, Heidelberg, Deutschland
| | - C P Heußel
- Klinik für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Deutschland.,Translational Lung Research Center Heidelberg (TLRC) Member of the German Center for Lung Research (DZL), Universitätsklinikum Heidelberg, Heidelberg, Deutschland.,Diagnostische und Interventionelle Radiologie mit Nuklearmedizin, Thoraxklinik Heidelberg, Heidelberg, Deutschland
| | - H-U Kauczor
- Klinik für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Deutschland.,Translational Lung Research Center Heidelberg (TLRC) Member of the German Center for Lung Research (DZL), Universitätsklinikum Heidelberg, Heidelberg, Deutschland
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Martel L, Somers J, Berkmann C, Koepp F, Rothermel A, Pauvert O, Selfslag C, Farnan I. A nuclear magnetic resonance spectrometer concept for hermetically sealed magic angle spinning investigations on highly toxic, radiotoxic, or air sensitive materials. Rev Sci Instrum 2013; 84:055112. [PMID: 23742594 DOI: 10.1063/1.4805017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A concept to integrate a commercial high-resolution, magic angle spinning nuclear magnetic resonance (MAS-NMR) probe capable of very rapid rotation rates (70 kHz) in a hermetically sealed enclosure for the study of highly radiotoxic materials has been developed and successfully demonstrated. The concept centres on a conventional wide bore (89 mm) solid-state NMR magnet operating with industry standard 54 mm diameter probes designed for narrow bore magnets. Rotor insertion and probe tuning take place within a hermetically enclosed glovebox, which extends into the bore of the magnet, in the space between the probe and the magnet shim system. Oxygen-17 MAS-NMR measurements demonstrate the possibility of obtaining high quality spectra from small sample masses (~10 mg) of highly radiotoxic material and the need for high spinning speeds to improve the spectral resolution when working with actinides. The large paramagnetic susceptibility arising from actinide paramagnetism in (Th(1-x)U(x))O2 solid solutions gives rise to extensive spinning sidebands and poor resolution at 15 kHz, which is dramatically improved at 55 kHz. The first (17)O MAS-NMR measurements on NpO(2+x) samples spinning at 55 kHz are also reported. The glovebox approach developed here for radiotoxic materials can be easily adapted to work with other hazardous or even air sensitive materials.
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Affiliation(s)
- L Martel
- Joint Research Centre, Institute for Transuranium Elements, Postfach 2340, D76125 Karlsruhe, Germany.
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Brendler C, Pour Aryan N, Rieger V, Klinger S, Rothermel A. A Substrate Isolated LDO for an Inductively Powered Retinal Implant. BIOMED ENG-BIOMED TE 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-O/bmt-2013-4367/bmt-2013-4367.xml. [DOI: 10.1515/bmt-2013-4367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Linder P, Trzewik J, Rüffer M, Artmann GM, Digel I, Kurz R, Rothermel A, Robitzki A, Temiz Artmann A. Contractile tension and beating rates of self-exciting monolayers and 3D-tissue constructs of neonatal rat cardiomyocytes. Med Biol Eng Comput 2009; 48:59-65. [PMID: 19924460 DOI: 10.1007/s11517-009-0552-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 10/24/2009] [Indexed: 10/20/2022]
Abstract
The CellDrum technology (The term 'CellDrum technology' includes a couple of slightly different technological setups for measuring lateral mechanical tension in various types of cell monolayers or 3D-tissue constructs) was designed to quantify the contraction rate and mechanical tension of self-exciting cardiac myocytes. Cells were grown either within flexible, circular collagen gels or as monolayer on top of respective 1-mum thin silicone membranes. Membrane and cells were bulged outwards by air pressure. This biaxial strain distribution is rather similar the beating, blood-filled heart. The setup allowed presetting the mechanical residual stress level externally by adjusting the centre deflection, thus, mimicking hypertension in vitro. Tension was measured as oscillating differential pressure change between chamber and environment. A 0.5-mm thick collagen-cardiac myocyte tissue construct induced after 2 days of culturing (initial cell density 2 x 10(4) cells/ml), a mechanical tension of 1.62 +/- 0.17 microN/mm(2). Mechanical load is an important growth regulator in the developing heart, and the orientation and alignment of cardiomyocytes is stress sensitive. Therefore, it was necessary to develop the CellDrum technology with its biaxial stress-strain distribution and defined mechanical boundary conditions. Cells were exposed to strain in two directions, radially and circumferentially, which is similar to biaxial loading in real heart tissues. Thus, from a biomechanical point of view, the system is preferable to previous setups based on uniaxial stretching.
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Affiliation(s)
- P Linder
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, University of Leipzig, 04103, Leipzig, Germany.
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Willbold E, Rothermel A, Huhn J, Stelck S, Layer PG. Inhibition of alpha(1-6)-linked fucose decreases inner retinal cells and increases photoreceptors in chicken retinal reaggregates. Dev Neurosci 2002; 23:464-72. [PMID: 11872947 DOI: 10.1159/000048733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We investigated the developmental role of alpha(1-6)-linked fucose, applying Aleuria aurantia lectin to a specific retinal regeneration system. Thereby, dissociated retinal cells of chicken embryos reaggregate, proliferate, and differentiate in vitro into histotypical spheres, so-called retinospheroids. Under the influence of A. aurantia lectin, processes of proliferation, differentiation and histogenesis of retinospheroids were disturbed. Extending these in vitro studies, we here show that A. aurantia lectin treatment decreases cells of the inner half retina and their processes into inner plexiform layer areas, as revealed by quantitative enzyme histochemistry for butyryl- and acetylcholinesterase, and immunohistochemistry using antibodies to acetylcholinesterase, Pax-6, calbindin-D, and F11. Concomitantly, the number of rod and red/green photoreceptors dramatically increases, using the antibodies rho4D2 and CERN901 (both specific for rods) and CERN906 (specific for red/green cones). These findings show that glycoproteins exhibiting fucose in alpha(1-6)-linkage are involved in processes determining retinal cell fate, strongly shifting the relative ratio of cells of the inner towards cells of the outer retina.
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Affiliation(s)
- E Willbold
- Technische Universität Darmstadt, Institut für Zoologie, Darmstadt, Germany.
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Willbold E, Rothermel A, Huhn J, Reinicke M, Layer PG. Cerebellar glia cells induce a correct laminar organization in chicken retinal reaggregates. Cells Tissues Organs 2001; 169:104-12. [PMID: 11399850 DOI: 10.1159/000047868] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We investigated the functional role of glia cells during retinogenesis using the rotation culture system. Reaggregating cells from the embryonic chick retina have the unique capacity to reassemble into laminated cellular spheres. These spheres are composed of several compartments holding the constituents of many retinal layers in a topologically correct, yet inverse orientation. However, when these spheres are cultured in the presence of conditioned media derived from monolayers of cerebellar glia cells, the reassembling retinal cells behave totally differently. The anlage of the originally reversed lamina polarity is progressively transformed within a week into a sphere with a compound and correctly laminated orientation. Conditioned media from fibroblasts, other glia cells (except Müller cells) or a set of already characterized retinogenetic factors are not able to produce this dramatic transformation. Additionally, we were able to show that only retinal cells are able to respond with a reorganization process. Reaggregating cells from the chick cerebellum also form spheroids; however, neither in the presence of cerebellar glia cell-derived conditioned medium nor their control counterparts are they able to reassemble histotypically. This indicates that cerebellar glia cells produce diffusible factors to which retinal cells can respond and that these factors can act as important determinants for the correct establishment of the retinal polarity. Since all types of laminar disorganization are of great clinical significance, the knowledge of factors which determine and sustain the normal retinal architecture are biomedically highly relevant.
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Affiliation(s)
- E Willbold
- Institut für Zoologie, Technische Universität Darmstadt, Darmstadt, Deutschland.
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Abstract
Cells from dissociated embryonic avian retinae have the capacity to re-aggregate in rotation culture and form cellular spheres reconstituting a complete arrangement of all retinal layers. This exquisite phenomenon is based upon in vitro proliferation of multipotent precursor stem cells and spatial organization of their differentiating descendants. The addition of soluble factors from cultured retinal pigmented epithelial (RPE) or radial glial cells is essential to revert inside-out spheres (rosetted retinal spheres) into correctly laminated outside-out spheres (stratified spheres). Such complete restoration of a laminated brain tissue by cell re-aggregation has been achieved only for the embryonic avian retina, but not the mammalian retina, nor for other brain parts. This review summarises the history of the re-aggregation approach, presents avian retinal re-aggregate models, and analyses roles of the RPE and Müller cells for successful retinal tissue regeneration. It is predicted that these results will become biomedically relevant, as stem cell biology will soon open ways to produce large amounts of human retinal precursors.
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Affiliation(s)
- P G Layer
- Darmstadt University of Technology, Department of Developmental Biology and Neurogenetics, Germany
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Abstract
Plasticity of photoreceptors and their integration into epithelial structures homologous to an outer nuclear layer (ONL), was investigated in embryonic chick retinal cell reaggregates by immunohistochemistry using an antibody specific for red plus green cones (RG-cones) and an antibody for rods. If reaggregates are raised in the presence of pigmented epithelium (RPE), completely reconstructed, stratified retinal spheres are produced, where all rods and cones are integrated into an outer laminar ONL, similar to a normal retina. In the absence of RPE, 'rosetted' spheres form which contain internal rosettes homologous to an ONL. Only a minor fraction of cones and rods of 'rosetted' spheres are located within rosettes, while a larger fraction is diffusely displaced in nonorganized areas, thus, not contributing to an ONL-like epithelium. In both types of spheres, the total percentage of RG-cones was similar to the in vivo retina, indicating that expression of cones is autonomous. Following cones, after about one day, rods developed only within already existing RG-cone clusters. Thereby, the ratio of rods to RG-cones increases as the tissue organization decreases: for stratified spheres this ratio is, 0.50 (1 rod/2 cones; similar to mature retina); for rosettes, 0.74 (3 rods/4 cones) and for nonorganized areas, 1.09 (1 rod/1 cone) -- a higher ratio under our conditions has never been detected. Thus, rod expression depends strictly on the presence of nearby cones; their relative numbers are distinctively adjusted according to the cytoarchitecture of the tissue environment. The biomedical implications of these findings are briefly discussed.
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Affiliation(s)
- A Rothermel
- Darmstadt University of Technology, Developmental Biology & Neurogenetics, Schnittspahnstrasse 3, D-64287 Darmstadt, Germany
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Willbold E, Rothermel A, Tomlinson S, Layer PG. Müller glia cells reorganize reaggregating chicken retinal cells into correctly laminated in vitro retinae. Glia 2000; 29:45-57. [PMID: 10594922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Müller cells, that belong to the family of radial glia cells, have central functions during retinogenesis. They form a stabilizing scaffold, they are candidate targets for the mediation of extraneous retinogenetic factors, and they are an important source for retina-borne retinogenetic factors. Reaggregate cultures allow the analysis of retinogenesis from dispersed cells to fully laminated tissues. Reaggregating cells from the embryonic chick retina reassemble to reversed laminated cellular spheres including constituents of all retinal layers, yet the outer nuclear layer is represented by internal rosettes. Using spheroids, we tested whether Müller cells have a decisive function in establishing retinal polarity and in determining the lamination pattern. To this end, we established confluent monolayers of highly enriched Müller cells derived from E6 or E13 chicken retinas, and then let dispersed E5.5 retinal cells reaggregate either in the absence of these monolayers or on top of them. In the presence of Müller cells, the reversed lamina polarity of rosetted spheroids progressively transformed within a week into correctly laminated retinal spheres, whereas all initial rosettes vanished. Moreover, photoreceptors formed a regular outer nuclear layer, as visualized by the rod-specific CERN901 antibody. In correctly laminated spheroids, staining for vimentin and glutamine synthetase was much more pronounced than in rosetted spheroids; in particular, a well-established inner limiting membrane stood out wherever the retinal lamination was complete. Because these effects can be similarly achieved by supernatants derived from Müller cells, direct cell-cell contacts or cellular replenishment from the monolayer do not account for these effects. We conclude that Müller cells are involved in the establishment of a correct retinal lamination and in the arrangement of the cells in the reaggregate cultures. In particular, rosette formation is counteracted and the formation of an inner limiting membrane is induced. Because rosettes are objects of concern in several ophthalmological defects, these results are highly relevant, both biomedically and also for normal retinogenesis.
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Affiliation(s)
- E Willbold
- Darmstadt University of Technology, Institute for Zoology, Department of Developmental Biology and Neurogenetics, Darmstadt, Germany.
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Layer PG, Rothermel A, Willbold E. Inductive effects of the retinal pigmented epithelium (RPE) on histogenesis of the avian retina as revealed by retinospheroid technology. Semin Cell Dev Biol 1998; 9:257-62. [PMID: 9665860 DOI: 10.1006/scdb.1998.0234] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During eye formation, inductive phenomena occurring between retinal pigmented epithelium (RPE) and retina are not well understood. After briefly summarizing the normal development of retina and RPE, we present three-dimensional in vitro models of the chick embryonic retina which allows elucidation of RPE-retina interactions. In such retinospheroids, a complete arrangement of layers is achieved, provided that dispersed retinal cells are: (1) young enough; and (2) reaggregated on a monolayer of RPE. Thereby, the RPE extends cell proliferation, while differentiation is much delayed. These findings assign to the RPE a decisive role for the genesis and regeneration of a vertebrate retina.
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Affiliation(s)
- P G Layer
- Faculty of Biology, Darmstadt University of Technology, Schnittspahnstrasse 3, Darmstadt, D-64287, Germany
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Rothermel A, Willbold E, Degrip WJ, Layer PG. Pigmented epithelium induces complete retinal reconstitution from dispersed embryonic chick retinae in reaggregation culture. Proc Biol Sci 1997; 264:1293-302. [PMID: 9332014 PMCID: PMC1688576 DOI: 10.1098/rspb.1997.0179] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Reaggregation of dispersed retinal cells of the chick embryo leads to histotypic retinospheroids in which the laminar organization remains incomplete: photoreceptors form rosettes which are surrounded by constituents of the other retinal layers. Here, for the first time, a complete arrangement of layers is achieved in cellular spheres (stratoids), provided that fully dispersed retinal cells are younger than embryonic day E6, and are reaggregated in the presence of a monolayer of retinal pigmented epithelium (RPE). A remarkable mechanism of stratoid formation from 1 to 15 days in vitro is revealed by the establishment of a radial Müller glia scaffold and of photoreceptors. During the first two days of reaggregation on RPE, rosettes are still observed. At this stage immunostaining with vimentin and F11 antibodies for radial Müller glia reveal a disorganized pattern. Subsequently, radial glia processes organize into long parallel fibre bundles which are arranged like spokes to stabilize the surface and centre of the stratoid. The opsin-specific antibody CERN 901 detects photoreceptors as they gradually build up an outer nuclear layer at the surface. These findings assign to the RPE a decisive role for the genesis and regeneration of a vertebrate retina.
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Affiliation(s)
- A Rothermel
- Department of Developmental Biology and Neurogenetics, Darmstadt University of Technology, Germany
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Layer PG, Rothermel A, Hering H, Wolf B, deGrip WJ, Hicks D, Willbold E. Pigmented epithelium sustains cell proliferation and decreases expression of opsins and acetylcholinesterase in reaggregated chicken retinospheroids. Eur J Neurosci 1997; 9:1795-803. [PMID: 9383202 DOI: 10.1111/j.1460-9568.1997.tb00746.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated the effect of the retinal pigmented epithelium on cell proliferation and differentiation in rosetted retinospheroids, which are retina-like spheres reaggregated in the complete absence of retinal pigmented epithelium from dissociated retinal cells of 6-day-old chick embryos in a rotation culture system. In spheroids raised in the absence of retinal pigmented epithelium (controls), acetylcholinesterase was expressed in cells of an inner nuclear-like layer and their neuropil matrices. Moreover, the ratio between rods and cones was found to be approximately normal throughout the spheroid. When spheroids were cultured in the presence of retinal pigmented epithelium monolayers, cell proliferation in spheroids as determined by BrdU labelling was significantly increased and extended for 1 week, while acetylcholinesterase protein levels and specific activities in homogenates were decreased to approximately 30%. At the same time, opsin immunoreactivity was completely suppressed within the spheroid and appeared slowly in cells around its periphery; i.e. the proportion of rhodopsin-positive cells decreased from 14 to 3%. This study reveals that the retinal pigmented epithelium in vitro sustains cell proliferation but inhibits the differentiation of acetylcholinesterase-positive cells and of photoreceptors.
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Affiliation(s)
- P G Layer
- Darmstadt University of Technology, Institute for Zoology, Germany
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