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Wüstner D, Egebjerg JM, Lauritsen L. Dynamic Mode Decomposition of Multiphoton and Stimulated Emission Depletion Microscopy Data for Analysis of Fluorescent Probes in Cellular Membranes. Sensors (Basel) 2024; 24:2096. [PMID: 38610307 PMCID: PMC11013970 DOI: 10.3390/s24072096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/14/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024]
Abstract
An analysis of the membrane organization and intracellular trafficking of lipids often relies on multiphoton (MP) and super-resolution microscopy of fluorescent lipid probes. A disadvantage of particularly intrinsically fluorescent lipid probes, such as the cholesterol and ergosterol analogue, dehydroergosterol (DHE), is their low MP absorption cross-section, resulting in a low signal-to-noise ratio (SNR) in live-cell imaging. Stimulated emission depletion (STED) microscopy of membrane probes like Nile Red enables one to resolve membrane features beyond the diffraction limit but exposes the sample to a lot of excitation light and suffers from a low SNR and photobleaching. Here, dynamic mode decomposition (DMD) and its variant, higher-order DMD (HoDMD), are applied to efficiently reconstruct and denoise the MP and STED microscopy data of lipid probes, allowing for an improved visualization of the membranes in cells. HoDMD also allows us to decompose and reconstruct two-photon polarimetry images of TopFluor-cholesterol in model and cellular membranes. Finally, DMD is shown to not only reconstruct and denoise 3D-STED image stacks of Nile Red-labeled cells but also to predict unseen image frames, thereby allowing for interpolation images along the optical axis. This important feature of DMD can be used to reduce the number of image acquisitions, thereby minimizing the light exposure of biological samples without compromising image quality. Thus, DMD as a computational tool enables gentler live-cell imaging of fluorescent probes in cellular membranes by MP and STED microscopy.
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Affiliation(s)
- Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; (J.M.E.); (L.L.)
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2
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Inavalli VVGK, Puente Muñoz V, Draffin JE, Tønnesen J. Fluorescence microscopy shadow imaging for neuroscience. Front Cell Neurosci 2024; 18:1330100. [PMID: 38425431 PMCID: PMC10902105 DOI: 10.3389/fncel.2024.1330100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/01/2024] [Indexed: 03/02/2024] Open
Abstract
Fluorescence microscopy remains one of the single most widely applied experimental approaches in neuroscience and beyond and is continuously evolving to make it easier and more versatile. The success of the approach is based on synergistic developments in imaging technologies and fluorophore labeling strategies that have allowed it to greatly diversify and be used across preparations for addressing structure as well as function. Yet, while targeted labeling strategies are a key strength of fluorescence microscopy, they reciprocally impose general limitations on the possible types of experiments and analyses. One recent development that overcomes some of these limitations is fluorescence microscopy shadow imaging, where membrane-bound cellular structures remain unlabeled while the surrounding extracellular space is made to fluoresce to provide a negative contrast shadow image. When based on super-resolution STED microscopy, the technique in effect provides a positive image of the extracellular space geometry and entire neuropil in the field of view. Other noteworthy advantages include the near elimination of the adverse effects of photobleaching and toxicity in live imaging, exhaustive and homogeneous labeling across the preparation, and the ability to apply and adjust the label intensity on the fly. Shadow imaging is gaining popularity and has been applied on its own or combined with conventional positive labeling to visualize cells and synaptic proteins in their parenchymal context. Here, we highlight the inherent limitations of fluorescence microscopy and conventional labeling and contrast these against the pros and cons of recent shadow imaging approaches. Our aim is to describe the brief history and current trajectory of the shadow imaging technique in the neuroscience field, and to draw attention to its ease of application and versatility.
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Affiliation(s)
| | - Virginia Puente Muñoz
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- Neuronal Excitability Lab, Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Jonathan E. Draffin
- Neuronal Excitability Lab, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Aligning Science Across Parkinson’s (ASAP), Collaborative Research Network, Chevy Chase, MD, United States
| | - Jan Tønnesen
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- Neuronal Excitability Lab, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Aligning Science Across Parkinson’s (ASAP), Collaborative Research Network, Chevy Chase, MD, United States
- Instituto Biofisika (CSIC/UPV), Leioa, Spain
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3
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Abstract
Peroxisomes are highly dynamic, oxidative organelles with key metabolic functions in cellular lipid metabolism, such as the β-oxidation of fatty acids and the synthesis of myelin sheath lipids, as well as the regulation of cellular redox balance. Loss of peroxisomal functions causes severe metabolic disorders in humans. Furthermore, peroxisomes also fulfil protective roles in pathogen and viral defence and immunity, highlighting their wider significance in human health and disease. This has sparked increasing interest in peroxisome biology and their physiological functions. This review presents an update and a continuation of three previous review articles addressing the unsolved mysteries of this remarkable organelle. We continue to highlight recent discoveries, advancements, and trends in peroxisome research, and address novel findings on the metabolic functions of peroxisomes, their biogenesis, protein import, membrane dynamics and division, as well as on peroxisome-organelle membrane contact sites and organelle cooperation. Furthermore, recent insights into peroxisome organisation through super-resolution microscopy are discussed. Finally, we address new roles for peroxisomes in immune and defence mechanisms and in human disorders, and for peroxisomal functions in different cell/tissue types, in particular their contribution to organ-specific pathologies.
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Grants
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- European Union’s Horizon 2020 research and innovation programme
- Deutsches Zentrum für Herz-Kreislaufforschung
- German Research Foundation
- Medical Faculty Mannheim, University of Heidelberg
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Affiliation(s)
- Rechal Kumar
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Markus Islinger
- Institute of Neuroanatomy, Medical Faculty Mannheim, Mannheim Centre for Translational Neuroscience, University of Heidelberg, 68167, Mannheim, Germany
| | - Harley Worthy
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Ruth Carmichael
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - Michael Schrader
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
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4
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Olejárová S, Horváth D, Huntošová V. The Remodulation of Actin Bundles during the Stimulation of Mitochondria in Adult Human Fibroblasts in Response to Light. Pharmaceutics 2023; 16:20. [PMID: 38258031 PMCID: PMC10818370 DOI: 10.3390/pharmaceutics16010020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/12/2023] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
β-actin belongs to cytoskeletal structures that change dynamically in cells according to various stimuli. Human skin can be considered as an organ that is very frequently exposed to various stress factors, of which light plays an important role. The present study focuses on adult human fibroblasts exposed to two types of light stress. Orange light with a wavelength of 590 nm was used here to stimulate the photosensitizer localized in the cells as a residual dose of photodynamic therapy (PDT). On the other hand, near-infrared light with a wavelength of 808 nm was considered for photobiomodulation (PBM), which is often used in healing processes. Confocal fluorescence microscopy was used to observe changes in intercellular communication, mitochondrial structures, and cytoskeletal dynamics defined by the remodulation of β-actin of fibroblasts. The number of β-actin bundles forming spherical structures was detected after light exposure. These structures as β-actin oligomers were confirmed with super-resolution microscopy. While PDT led to the disintegration of actin oligomers, PBM increased their number. The interaction of β-actin with mitochondria was observed. The combination of PDT and PBM treatments is important to minimize the side effects of cancer treatment with PDT on healthy cells, as shown by the cell metabolism assay in this work. In this work, β-actin is presented as an important parameter that changes and is involved in the response of cells to PDT and PBM.
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Affiliation(s)
- Soňa Olejárová
- Department of Biophysics, Institute of Physics, Faculty of Science, P.J. Šafárik University in Košice, Jesenná 5, 041 54 Kosice, Slovakia;
| | - Denis Horváth
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Šafárik University in Košice, Jesenná 5, 041 54 Košice, Slovakia;
| | - Veronika Huntošová
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Šafárik University in Košice, Jesenná 5, 041 54 Košice, Slovakia;
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5
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Knobloch JA, Laurent G, Lauterbach MA. STED microscopy reveals dendrite-specificity of spines in turtle cortex. Prog Neurobiol 2023; 231:102541. [PMID: 37898315 DOI: 10.1016/j.pneurobio.2023.102541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/20/2023] [Accepted: 10/21/2023] [Indexed: 10/30/2023]
Abstract
Dendritic spines are key structures for neural communication, learning and memory. Spine size and shape probably reflect synaptic strength and learning. Imaging with superresolution STED microscopy the detailed shape of the majority of the spines of individual neurons in turtle cortex (Trachemys scripta elegans) revealed several distinguishable shape classes. Dendritic spines of a given class were not distributed randomly, but rather decorated significantly more often some dendrites than others. The individuality of dendrites was corroborated by significant inter-dendrite differences in other parameters such as spine density and length. In addition, many spines were branched or possessed spinules. These findings may have implications for the role of individual dendrites in this cortex.
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Affiliation(s)
- Jan A Knobloch
- Department of Molecular Imaging, Center for Integrative Physiology and Molecular Medicine, Saarland University, Building 48, 66421 Homburg, Germany
| | - Gilles Laurent
- Max Planck Institute for Brain Research, Max-von-Laue-Str. 4, 60438 Frankfurt am Main, Germany
| | - Marcel A Lauterbach
- Department of Molecular Imaging, Center for Integrative Physiology and Molecular Medicine, Saarland University, Building 48, 66421 Homburg, Germany; Max Planck Institute for Brain Research, Max-von-Laue-Str. 4, 60438 Frankfurt am Main, Germany.
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Baldini F, Zeaiter L, Diab F, Zbeeb H, Cuneo L, Pagano A, Portincasa P, Diaspro A, Vergani L. Nuclear and chromatin rearrangement associate to epigenome and gene expression changes in a model of in vitro adipogenesis and hypertrophy. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159368. [PMID: 37499858 DOI: 10.1016/j.bbalip.2023.159368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 07/07/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
Hypertrophy of adipocytes represents the main cause of obesity. We investigated in vitro the changes associated with adipocyte differentiation and hypertrophy focusing on the nuclear morphometry and chromatin epigenetic remodelling. The 3 T3-L1 pre-adipocytes were firstly differentiated into mature adipocytes, then cultured with long-chain fatty acids to induce hypertrophy. Confocal and super-resolution stimulation emission depletion (STED) microscopy combined with ELISA assays allowed us to explore nuclear architecture, chromatin distribution and epigenetic modifications. In each condition, we quantified the triglyceride accumulation, the mRNA expression of adipogenesis and dysfunction markers, the release of five pro-inflammatory cytokines. Confocal microscopy revealed larger volume and less elongated shape of the nuclei in both mature and hypertrophic cells respect to pre-adipocytes, and a trend toward reduced chromatin compaction. Compared to mature adipocytes, the hypertrophic phenotype showed larger triglyceride content, increased PPARγ expression reduced IL-1a release, and up-regulation of a pool of genes markers for adipose tissue dysfunction. Moreover, a remodelling of both epigenome and chromatin organization was observed in hypertrophic adipocytes, with an increase in the average fluorescence of H3K9 acetylated domains in parallel with the increase in KAT2A expression, and a global hypomethylation of DNA. These findings making light on the nuclear changes during adipocyte differentiation and hypertrophy might help the strategies for treating obesity and metabolic complications.
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Affiliation(s)
- Francesca Baldini
- Nanoscopy, Istituto Italiano Tecnologia, Via Enrico Melen 83, 16152, Genova, Italy
| | - Lama Zeaiter
- Nanoscopy, Istituto Italiano Tecnologia, Via Enrico Melen 83, 16152, Genova, Italy; Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy
| | - Farah Diab
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy
| | - Hawraa Zbeeb
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy
| | - Lisa Cuneo
- Nanoscopy, Istituto Italiano Tecnologia, Via Enrico Melen 83, 16152, Genova, Italy; Department of Physics (DIFILAB), University of Genoa, Via Dodecaneso 33, 16146, Genoa, Italy
| | - Aldo Pagano
- DIMES, Department of Experimental Medicine, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Piero Portincasa
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari, Medical School, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Alberto Diaspro
- Nanoscopy, Istituto Italiano Tecnologia, Via Enrico Melen 83, 16152, Genova, Italy; Department of Physics (DIFILAB), University of Genoa, Via Dodecaneso 33, 16146, Genoa, Italy
| | - Laura Vergani
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
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7
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Richards CJ, Burgers TCQ, Vlijm R, Roos WH, Åberg C. Rapid Internalization of Nanoparticles by Human Cells at the Single Particle Level. ACS Nano 2023; 17:16517-16529. [PMID: 37642490 PMCID: PMC10510712 DOI: 10.1021/acsnano.3c01124] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023]
Abstract
Nanoparticle uptake by cells has been studied for applications both in nanomedicine and in nanosafety. While the majority of studies have focused on the biological mechanisms underlying particle internalization, less attention has been given to questions of a more quantitative nature, such as how many nanoparticles enter cells and how rapidly they do so. To address this, we exposed human embryonic kidney cells to 40-200 nm carboxylated polystyrene nanoparticles and the particles were observed by live-cell confocal and super-resolution stimulated emission depletion fluorescence microscopy. How long a particle remained at the cell membrane after adsorbing onto it was monitored, distinguishing whether the particle ultimately desorbed again or was internalized by the cell. We found that the majority of particles desorb, but interestingly, most of the particles that are internalized do so within seconds, independently of particle size. As this is faster than typical endocytic mechanisms, we interpret this observation as the particles entering via an endocytic event that is already taking place (as opposed to directly triggering their own uptake) or possibly via an as yet uncharacterized endocytic route. Aside from the rapidly internalizing particles, a minority of particles remain at the membrane for tens of seconds to minutes before desorbing or being internalized. We also followed particles after cell internalization, observing particles that appeared to exit the cell, sometimes as rapidly as within tens of seconds. Overall, our results provide quantitative information about nanoparticle cell internalization times and early trafficking.
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Affiliation(s)
- Ceri J. Richards
- Pharmaceutical
Analysis, Groningen Research Institute of Pharmacy, University of Groningen, 9713 AV Groningen, The Netherlands
- Molecular
Biophysics, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Thomas C. Q. Burgers
- Molecular
Biophysics, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Rifka Vlijm
- Molecular
Biophysics, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Wouter H. Roos
- Molecular
Biophysics, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Christoffer Åberg
- Pharmaceutical
Analysis, Groningen Research Institute of Pharmacy, University of Groningen, 9713 AV Groningen, The Netherlands
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Idziak A, Inavalli VVGK, Bancelin S, Arizono M, Nägerl UV. The Impact of Chemical Fixation on the Microanatomy of Mouse Organotypic Hippocampal Slices. eNeuro 2023; 10:ENEURO.0104-23.2023. [PMID: 37709524 PMCID: PMC10521345 DOI: 10.1523/eneuro.0104-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 09/16/2023] Open
Abstract
Chemical fixation using paraformaldehyde (PFA) is a standard step for preserving cells and tissues for subsequent microscopic analyses such as immunofluorescence or electron microscopy (EM). However, chemical fixation may introduce physical alterations in the spatial arrangement of cellular proteins, organelles, and membranes. With the increasing use of super-resolution microscopy to visualize cellular structures with nanometric precision, assessing potential artifacts, and knowing how to avoid them, takes on special urgency. We addressed this issue by taking advantage of live-cell super-resolution microscopy that makes it possible to directly observe the acute effects of PFA on organotypic hippocampal brain slices, allowing us to compare tissue integrity in a "before-and-after" experiment. We applied super-resolution shadow imaging (SUSHI) to assess the structure of the extracellular space (ECS) and regular super-resolution microscopy of fluorescently labeled neurons and astrocytes to quantify key neuroanatomical parameters. While the ECS volume fraction (VF) and microanatomic organization of astrocytes remained largely unaffected by the PFA treatment, we detected subtle changes in dendritic spine morphology and observed substantial damage to cell membranes. Our experiments show that PFA application via immersion does not cause a noticeable shrinkage of the ECS in hippocampal brain slices maintained in culture, unlike the situation in transcardially perfused animals in vivo where the ECS typically becomes nearly depleted. Our study outlines an experimental strategy to evaluate the quality and pitfalls of various fixation protocols for the molecular and morphologic preservation of cells and tissues.
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Affiliation(s)
- Agata Idziak
- Unité Mixte de Recherche 5297, Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, University of Bordeaux, Bordeaux F-33000, France
| | - V V G Krishna Inavalli
- Unité Mixte de Recherche 5297, Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, University of Bordeaux, Bordeaux F-33000, France
| | - Stéphane Bancelin
- Unité Mixte de Recherche 5297, Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, University of Bordeaux, Bordeaux F-33000, France
| | - Misa Arizono
- Unité Mixte de Recherche 5297, Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, University of Bordeaux, Bordeaux F-33000, France
- Department of Pharmacology, Kyoto University Graduate School of Medicine/The Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8501, Japan
| | - U Valentin Nägerl
- Unité Mixte de Recherche 5297, Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, University of Bordeaux, Bordeaux F-33000, France
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Townes-Anderson E, Halász É, Sugino I, Davidow AL, Frishman LJ, Fritzky L, Yousufzai FAK, Zarbin M. Injury to Cone Synapses by Retinal Detachment: Differences from Rod Synapses and Protection by ROCK Inhibition. Cells 2023; 12:1485. [PMID: 37296606 PMCID: PMC10253016 DOI: 10.3390/cells12111485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Attachment of a detached retina does not always restore vision to pre-injury levels, even if the attachment is anatomically successful. The problem is due in part to long-term damage to photoreceptor synapses. Previously, we reported on damage to rod synapses and synaptic protection using a Rho kinase (ROCK) inhibitor (AR13503) after retinal detachment (RD). This report documents the effects of detachment, reattachment, and protection by ROCK inhibition on cone synapses. Conventional confocal and stimulated emission depletion (STED) microscopy were used for morphological assessment and electroretinograms for functional analysis of an adult pig model of RD. RDs were examined 2 and 4 h after injury or two days later when spontaneous reattachment had occurred. Cone pedicles respond differently than rod spherules. They lose their synaptic ribbons, reduce invaginations, and change their shape. ROCK inhibition protects against these structural abnormalities whether the inhibitor is applied immediately or 2 h after the RD. Functional restoration of the photopic b-wave, indicating cone-bipolar neurotransmission, is also improved with ROCK inhibition. Successful protection of both rod and cone synapses with AR13503 suggests this drug will (1) be a useful adjunct to subretinal administration of gene or stem cell therapies and (2) improve recovery of the injured retina when treatment is delayed.
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Affiliation(s)
- Ellen Townes-Anderson
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA;
| | - Éva Halász
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA;
| | - Ilene Sugino
- Institute of Ophthalmology and Visual Science, Rutgers New Jersey Medical School, 90 Bergen Street, Newark, NJ 07103, USA; (I.S.); (M.Z.)
| | - Amy L. Davidow
- Department of Biostatistics, New York University School of Global Public Health, 708 Broadway, New York, NY 10003, USA;
| | - Laura J. Frishman
- Department of Vision Sciences, College of Optometry, University of Houston, Martin Luther King Blvd, Houston, TX 77204, USA;
| | - Luke Fritzky
- Cellular Imaging and Histology Core, Rutgers New Jersey Medical School, 205 South Orange Avenue, Newark, NJ 07103, USA; (L.F.); (F.A.K.Y.)
| | - Fawad A. K. Yousufzai
- Cellular Imaging and Histology Core, Rutgers New Jersey Medical School, 205 South Orange Avenue, Newark, NJ 07103, USA; (L.F.); (F.A.K.Y.)
| | - Marco Zarbin
- Institute of Ophthalmology and Visual Science, Rutgers New Jersey Medical School, 90 Bergen Street, Newark, NJ 07103, USA; (I.S.); (M.Z.)
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Heils L, Schneemann M, Gerhard R, Schulzke JD, Bücker R. CDT of Clostridioides difficile Induces MLC-Dependent Intestinal Barrier Dysfunction in HT-29/B6 Epithelial Cell Monolayers. Toxins (Basel) 2023; 15:54. [PMID: 36668874 PMCID: PMC9866553 DOI: 10.3390/toxins15010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Background: Clostridioides difficile binary toxin (CDT) defines the hypervirulence of strains in nosocomial antibiotic-induced colitis with the highest mortality. The objective of our study was to investigate the impact of CDT on the intestinal epithelial barrier and to enlighten the underlying molecular mechanisms. Methods: Functional measurements of epithelial barrier function by macromolecular permeability and electrophysiology were performed in human intestinal HT-29/B6 cell monolayers. Molecular analysis of the spatial distribution of tight junction protein and cytoskeleton was performed by super-resolution STED microscopy. Results: Sublethal concentrations of CDT-induced barrier dysfunction with decreased TER and increased permeability for 332 Da fluorescein and 4 kDa FITC-dextran. The molecular correlate to the functional barrier defect by CDT was found to be a tight junction protein subcellular redistribution with tricellulin, occludin, and claudin-4 off the tight junction domain. This redistribution was shown to be MLCK-dependent. Conclusions: CDT compromised epithelial barrier function in a human intestinal colonic cell model, even in sublethal concentrations, pointing to barrier dysfunction in the intestine and leak flux induction as a diarrheal mechanism. However, this cannot be attributed to the appearance of apoptosis and necrosis, but rather to an opening of the paracellular leak pathway as the result of epithelial tight junction alterations.
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Affiliation(s)
- Lucas Heils
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Martina Schneemann
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany
| | - Jörg-Dieter Schulzke
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Roland Bücker
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
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Abstract
Recent advances in stimulated emission depletion (STED) microscopy offer an unparalleled avenue to study membrane dynamics of exo- and endocytosis, such as fusion pore opening, pore expansion, constriction, and closure, as well as the membrane transformation from flat-shaped to round-shaped vesicles in real time. Here we depict a method of using the state-of-the-art STED microscopy to image these membrane dynamics in bovine chromaffin cells. This method can potentially be applied to study other membrane structure dynamics in other cell model system.
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Affiliation(s)
- Chung Yu Chan
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.
| | - Sue Han
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Xin Wang
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Xiaoli Guo
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Ling-Gang Wu
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.
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12
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Aktalay A, Ponsot F, Bossi ML, Belov VN, Hell SW. Cleavable Linker Incorporation into a Synthetic Dye-Nanobody-Fluorescent Protein Assembly: FRET, FLIM and STED Microscopy. Chembiochem 2022; 23:e202200395. [PMID: 35838445 PMCID: PMC9804610 DOI: 10.1002/cbic.202200395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Indexed: 01/05/2023]
Abstract
A bright and photostable fluorescent dye with a disulfide (S-S) linker and maleimide group (Rho594-S2-mal), as cleavable and reactive sites, was synthesized and conjugated with anti-GFP nanobodies (NB). The binding of EGFP (FRET donor) with anti-GFP NB labeled with one or two Rho594-S2-mal residues was studied in vitro and in cellulo. The linker was cleaved with dithiothreitol recovering the donor (FP) signal. The bioconjugates (FP-NB-dye) were applied in FRET-FLIM assays, confocal imaging, and superresolution STED microscopy.
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Affiliation(s)
- Ayse Aktalay
- Department of Optical NanoscopyMax Planck Institute for Medical Research (MPI-MR)Jahnstraße 2969120HeidelbergGermany
| | - Flavien Ponsot
- Department of NanoBiophotonicsMax Planck Institute for Multidisciplinary Sciences (MPI-NAT)Am Fassberg 1137077GöttingenGermany
| | - Mariano L. Bossi
- Department of Optical NanoscopyMax Planck Institute for Medical Research (MPI-MR)Jahnstraße 2969120HeidelbergGermany
| | - Vladimir N. Belov
- Department of NanoBiophotonicsMax Planck Institute for Multidisciplinary Sciences (MPI-NAT)Am Fassberg 1137077GöttingenGermany
| | - Stefan W. Hell
- Department of Optical NanoscopyMax Planck Institute for Medical Research (MPI-MR)Jahnstraße 2969120HeidelbergGermany,Department of NanoBiophotonicsMax Planck Institute for Multidisciplinary Sciences (MPI-NAT)Am Fassberg 1137077GöttingenGermany
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13
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Wang Y, Soto Rodriguez PED, Woythe L, Sánchez S, Samitier J, Zijlstra P, Albertazzi L. Multicolor Super-Resolution Microscopy of Protein Corona on Single Nanoparticles. ACS Appl Mater Interfaces 2022; 14:37345-37355. [PMID: 35961006 PMCID: PMC9412947 DOI: 10.1021/acsami.2c06975] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Nanoparticles represent a promising class of material for nanomedicine and molecular biosensing. The formation of a protein corona due to nonspecific particle-protein interactions is a determining factor for the biological fate of nanoparticles in vivo and strongly impacts the performance of nanoparticles when used as biosensors. Nonspecific interactions are usually highly heterogeneous, yet little is known about the heterogeneity of the protein corona that may lead to inter- and intraparticle differences in composition and protein distribution. Here, we present a super-resolution microscopic approach to study the protein corona on single silica nanoparticles and subsequent cellular interactions using multicolor stimulated emission depletion (STED) microscopy. We demonstrate that STED resolves structural features of protein corona on single particles including the distribution on the particle surface and the degree of protein internalization in porous particles. Using multicolor measurements of multiple labeled protein species, we determine the composition of the protein corona at the single-particle level. We quantify particle-to-particle differences in the composition and find that the composition is considerably influenced by the particle geometry. In a subsequent cellular uptake measurement, we demonstrate multicolor STED of protein corona on single particles internalized by cells. Our study shows that STED microscopy opens the window toward mechanistic understanding of protein coronas and aids in the rational design of nanoparticles as nanomedicines and biosensors.
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Affiliation(s)
- Yuyang Wang
- Department
of Applied Physics and Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5612AZ Eindhoven, The Netherlands
| | - Paul E. D. Soto Rodriguez
- Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Laura Woythe
- Department
of Biomedical Engineering and Institute for Complex Molecular Systems
(ICMS), Eindhoven University of Technology, 5612AZ Eindhoven, The Netherlands
| | - Samuel Sánchez
- Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), Passeige Lluís Companys 23, 08010 Barcelona, Spain
| | - Josep Samitier
- Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Department
of Electronics and Biomedical Engineering, University of Barcelona (UB), 08028 Barcelona, Spain
- Biomedical
Research Networking Center in Bioengineering, Biomaterials, and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
| | - Peter Zijlstra
- Department
of Applied Physics and Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5612AZ Eindhoven, The Netherlands
| | - Lorenzo Albertazzi
- Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Department
of Biomedical Engineering and Institute for Complex Molecular Systems
(ICMS), Eindhoven University of Technology, 5612AZ Eindhoven, The Netherlands
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14
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Oakley JV, Buksh BF, Fernández DF, Oblinsky DG, Seath CP, Geri JB, Scholes GD, MacMillan DWC. Radius measurement via super-resolution microscopy enables the development of a variable radii proximity labeling platform. Proc Natl Acad Sci U S A 2022; 119:e2203027119. [PMID: 35914173 DOI: 10.1073/pnas.2203027119] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The elucidation of protein interaction networks is critical to understanding fundamental biology as well as developing new therapeutics. Proximity labeling platforms (PLPs) are state-of-the-art technologies that enable the discovery and delineation of biomolecular networks through the identification of protein-protein interactions. These platforms work via catalytic generation of reactive probes at a biological region of interest; these probes then diffuse through solution and covalently "tag" proximal biomolecules. The physical distance that the probes diffuse determines the effective labeling radius of the PLP and is a critical parameter that influences the scale and resolution of interactome mapping. As such, by expanding the degrees of labeling resolution offered by PLPs, it is possible to better capture the various size scales of interactomes. At present, however, there is little quantitative understanding of the labeling radii of different PLPs. Here, we report the development of a superresolution microscopy-based assay for the direct quantification of PLP labeling radii. Using this assay, we provide direct extracellular measurements of the labeling radii of state-of-the-art antibody-targeted PLPs, including the peroxidase-based phenoxy radical platform (269 ± 41 nm) and the high-resolution iridium-catalyzed µMap technology (54 ± 12 nm). Last, we apply these insights to the development of a molecular diffusion-based approach to tuning PLP resolution and introduce a new aryl-azide-based µMap platform with an intermediate labeling radius (80 ± 28 nm).
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15
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Ishii H, Otomo K, Takahashi T, Yamaguchi K, Nemoto T. Focusing new light on brain functions: multiphoton microscopy for deep and super-resolution imaging. Neurosci Res 2021:S0168-0102(21)00245-5. [PMID: 34861295 DOI: 10.1016/j.neures.2021.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 11/21/2022]
Abstract
Multiphoton microscopy has become a powerful tool for visualizing neurobiological phenomena such as the dynamics of individual synapses and the functional activities of neurons. Owing to its near-infrared excitation laser wavelength, multiphoton microscopy achieves greater penetration depth and is less invasive than single-photon excitation. Here, we review the principles of two-photon microscopy and its technical limitations (penetration depth and spatial resolution) on brain tissue imaging. We then describe the technological improvements of two-photon microscopy that enable deeper imaging with higher spatial resolution for investigating unrevealed brain functions.
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16
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Stiekema M, Ramaekers FCS, Kapsokalyvas D, van Zandvoort MAMJ, Veltrop RJA, Broers JLV. Super-Resolution Imaging of the A- and B-Type Lamin Networks: A Comparative Study of Different Fluorescence Labeling Procedures. Int J Mol Sci 2021; 22:ijms221910194. [PMID: 34638534 PMCID: PMC8508656 DOI: 10.3390/ijms221910194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/31/2022] Open
Abstract
A- and B-type lamins are type V intermediate filament proteins. Mutations in the genes encoding these lamins cause rare diseases, collectively called laminopathies. A fraction of the cells obtained from laminopathy patients show aberrations in the localization of each lamin subtype, which may represent only the minority of the lamina disorganization. To get a better insight into more delicate and more abundant lamina abnormalities, the lamin network can be studied using super-resolution microscopy. We compared confocal scanning laser microscopy and stimulated emission depletion (STED) microscopy in combination with different fluorescence labeling approaches for the study of the lamin network. We demonstrate the suitability of an immunofluorescence staining approach when using STED microscopy, by determining the lamin layer thickness and the degree of lamin A and B1 colocalization as detected in fixed fibroblasts (co-)stained with lamin antibodies or (co-)transfected with EGFP/YFP lamin constructs. This revealed that immunofluorescence staining of cells does not lead to consequent changes in the detected lamin layer thickness, nor does it influence the degree of colocalization of lamin A and B1, when compared to the transfection approach. Studying laminopathy patient dermal fibroblasts (LMNA c.1130G>T (p.(Arg377Leu)) variant) confirmed the suitability of immunofluorescence protocols in STED microscopy, which circumvents the need for less convenient transfection steps. Furthermore, we found a significant decrease in lamin A/C and B1 colocalization in these patient fibroblasts, compared to normal human dermal fibroblasts. We conclude that super-resolution light microscopy combined with immunofluorescence protocols provides a potential tool to detect structural lamina differences between normal and laminopathy patient fibroblasts.
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Affiliation(s)
- Merel Stiekema
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Frans C. S. Ramaekers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Dimitrios Kapsokalyvas
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- Interdisciplinary Center for Clinical Research, IZKF, RWTH Aachen University, 52074 Aachen, Germany
| | - Marc A. M. J. van Zandvoort
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- Institute for Molecular Cardiovascular Research IMCAR, RWTH Aachen University, 52074 Aachen, Germany
| | - Rogier J. A. Veltrop
- Institute for Molecular Cardiovascular Research IMCAR, RWTH Aachen University, 52074 Aachen, Germany
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, The Netherlands;
| | - Jos L. V. Broers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- Correspondence: ; Tel.: +31-433881366
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17
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Xu X, Zhao K, Ren W, Wu Z, Yu W, Shao C, Shi K, Xi P. A protocol for single-source dual-pulse stimulated emission depletion setup with Bessel modulation. Microsc Res Tech 2021; 85:813-823. [PMID: 34488243 DOI: 10.1002/jemt.23922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 01/01/2023]
Abstract
STimulated Emission Depletion (STED) microscopy attains super-resolution in biological imaging beyond the diffraction limit. Here, we give a concise protocol to construct a dual-pulse STED setup with one super-continuum laser. Moreover, a flexible and dismountable Bessel modulation module is introduced for potential 2D-stack STED imaging. Experiments and notices are introduced in detail, with discussion on some important check-points for STED, such as detector saturation. Finally, the results validate the system working.
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Affiliation(s)
- Xinzhu Xu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, People's Republic of China
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Kun Zhao
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, People's Republic of China
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Wei Ren
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, People's Republic of China
| | - Zhaoyang Wu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, People's Republic of China
| | - Wentao Yu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, People's Republic of China
| | - Chendi Shao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, People's Republic of China
| | - Kebin Shi
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, People's Republic of China
| | - Peng Xi
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, People's Republic of China
- UTS-SUStech Joint Research Centre for Biomedical Materials & Devices, Department of Biomedical Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, People's Republic of China
- National Biomedical Imaging Center, Peking University, Beijing, People's Republic of China
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18
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Ghithan JH, Noel JM, Roussel TJ, McCall MA, Alphenaar BW, Mendes SB. Photobleaching reduction in modulated super-resolution microscopy. Microscopy (Oxf) 2021; 70:278-288. [PMID: 33064828 DOI: 10.1093/jmicro/dfaa062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 11/13/2022] Open
Abstract
Important breakthroughs in far-field imaging techniques have been made since the first demonstrations of stimulated emission depletion (STED) microscopy. To date, the most straightforward and widespread deployment of STED microscopy has used continuous wave (CW) laser beams for both the excitation and depletion of fluorescence emission. A major drawback of the CW STED imaging technique has been photobleaching effects due to the high optical power needed in the depletion beam to reach sub-diffraction resolution. To overcome this hurdle, we have applied a synchronous detection approach based on modulating the excitation laser beam, while keeping the depletion beam at CW operation, and frequency filtering the collected signal with a lock-in amplifier to record solely the super-resolved fluorescence emission. We demonstrate here that such approach allows an important reduction in the optical power of both laser beams that leads to measurable decreases in photobleaching effects in STED microscopy. We report super-resolution images with relatively low powers for both the excitation and depletion beams. In addition, typical unwanted scattering effects and background signal generated from the depletion beam, which invariably arises from mismatches in refractive index in the material composing the sample, are largely reduced by using the modulated STED approach. The capability of acquiring super-resolution images with relatively low power is quite relevant for studying a variety of samples, but particularly important for biological species as exemplified in this work.
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Affiliation(s)
- Jafar H Ghithan
- University of Louisville, Department of Physics and Astronomy, 215 Eastern Pkwy, Louisville, Kentucky, United States, 40292
| | - Jennifer M Noel
- University of Louisville, Department of Anatomical Sciences and Neurobiology, 511 South Floyd, Louisville, Kentucky, United States, 40202
| | - Thomas J Roussel
- University of Louisville, Department of Bioengineering, J. B. Speed School of Engineering, Louisville, Kentucky, United States, 40292
| | - Maureen A McCall
- University of Louisville, Department of Ophthalmology and Visual Sciences, 301 E. Muhammad Ali Blvd., Louisville, Kentucky, United States, 40202
| | - Bruce W Alphenaar
- University of Louisville, Department of Electrical Engineering, J. B. Speed School of Engineering, Louisville, Kentucky, United States, 40292
| | - Sergio B Mendes
- University of Louisville, Department of Physics and Astronomy, 215 Eastern Pkwy, Louisville, Kentucky, United States, 40292
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19
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Calovi S, Soria FN, Tønnesen J. Super-resolution STED microscopy in live brain tissue. Neurobiol Dis 2021; 156:105420. [PMID: 34102277 DOI: 10.1016/j.nbd.2021.105420] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 12/25/2022] Open
Abstract
STED microscopy is one of several fluorescence microscopy techniques that permit imaging at higher spatial resolution than what the diffraction-limit of light dictates. STED imaging is unique among these super-resolution modalities in being a beam-scanning microscopy technique based on confocal or 2-photon imaging, which provides the advantage of superior optical sectioning in thick samples. Compared to the other super-resolution techniques that are based on widefield microscopy, this makes STED particularly suited for imaging inside live brain tissue, such as in slices or in vivo. Notably, the 50 nm resolution provided by STED microscopy enables analysis of neural morphologies that conventional confocal and 2-photon microscopy approaches cannot resolve, including all-important synaptic structures. Over the course of the last 20 years, STED microscopy has undergone extensive developments towards ever more versatile use, and has facilitated remarkable neurophysiological discoveries. The technique is still not widely adopted for live tissue imaging, even though one of its particular strengths is exactly in resolving the nanoscale dynamics of synaptic structures in brain tissue, as well as in addressing the complex morphologies of glial cells, and revealing the intricate structure of the brain extracellular space. Not least, live tissue STED microscopy has so far hardly been applied in settings of pathophysiology, though also here it shows great promise for providing new insights. This review outlines the technical advantages of STED microscopy for imaging in live brain tissue, and highlights key neurobiological findings brought about by the technique.
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Affiliation(s)
- Stefano Calovi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary; János Szentágothai Doctoral School, Semmelweis University, Budapest, Hungary; Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Federico N Soria
- Achucarro Basque Center for Neuroscience, Leioa, Spain; Department of Neuroscience, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Jan Tønnesen
- Achucarro Basque Center for Neuroscience, Leioa, Spain; Department of Neuroscience, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain.
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20
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Büttner M, Lagerholm CB, Waithe D, Galiani S, Schliebs W, Erdmann R, Eggeling C, Reglinski K. Challenges of Using Expansion Microscopy for Super-resolved Imaging of Cellular Organelles. Chembiochem 2021; 22:686-693. [PMID: 33049107 PMCID: PMC7894168 DOI: 10.1002/cbic.202000571] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/07/2020] [Indexed: 12/26/2022]
Abstract
Expansion microscopy (ExM) has been successfully used to improve the spatial resolution when imaging tissues by optical microscopy. In ExM, proteins of a fixed sample are crosslinked to a swellable acrylamide gel, which expands when incubated in water. Therefore, ExM allows enlarged subcellular structures to be resolved that would otherwise be hidden to standard confocal microscopy. Herein, we aim to validate ExM for the study of peroxisomes, mitochondria, nuclei and the plasma membrane. Upon comparison of the expansion factors of these cellular compartments in HEK293 cells within the same gel, we found significant differences, of a factor of above 2, in expansion factors. For peroxisomes, the expansion factor differed even between peroxisomal membrane and matrix marker; this underlines the need for a thorough validation of expansion factors of this powerful technique. We further give an overview of possible quantification methods for the determination of expansion factors of intracellular organelles, and we highlight some potentials and challenges.
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Affiliation(s)
- Maximilian Büttner
- MRC Human Immunology Unit MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
- Institute for Anatomy and Cell BiologyMartin-Luther-University Halle-WittenbergGroße Steinstraße 5206108HalleGermany
| | - Christoffer B. Lagerholm
- Wolfson Imaging Centre MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
| | - Dominic Waithe
- MRC Human Immunology Unit MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
- Wolfson Imaging Centre MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
| | - Silvia Galiani
- MRC Human Immunology Unit MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
- Wolfson Imaging Centre MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
| | - Wolfgang Schliebs
- Institute of Biochemistry and Pathobiochemistry Systemic BiochemistryRuhr-University BochumUniversitätsstraße 15044801BochumGermany
| | - Ralf Erdmann
- Institute of Biochemistry and Pathobiochemistry Systemic BiochemistryRuhr-University BochumUniversitätsstraße 15044801BochumGermany
| | - Christian Eggeling
- MRC Human Immunology Unit MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
- Leibniz-Institute of Photonic Technologies & Institute of Applied Optic and BiophysicsFriedrich-Schiller University JenaMax-Wien-Platz 107743JenaGermany
| | - Katharina Reglinski
- MRC Human Immunology Unit MRC Weatherall Institute of Molecular MedicineUniversity of Oxford Headley WayOxfordOX3 9DSUK
- Leibniz-Institute of Photonic Technologies & Institute of Applied Optic and BiophysicsFriedrich-Schiller University JenaMax-Wien-Platz 107743JenaGermany
- University Hospital JenaBachstraße 1807743JenaGermany
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21
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Hebisch E, Hjort M, Volpati D, Prinz CN. Nanostraw-Assisted Cellular Injection of Fluorescent Nanodiamonds via Direct Membrane Opening. Small 2021; 17:e2006421. [PMID: 33502091 DOI: 10.1002/smll.202006421] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Due to their stable fluorescence, biocompatibility, and amenability to functionalization, fluorescent nanodiamonds (FND) are promising materials for long term cell labeling and tracking. However, transporting them to the cytosol remains a major challenge, due to low internalization efficiencies and endosomal entrapment. Here, nanostraws in combination with low voltage electroporation pulses are used to achieve direct delivery of FND to the cytosol. The nanostraw delivery leads to efficient and rapid FND transport into cells compared to when incubating cells in a FND-containing medium. Moreover, whereas all internalized FND delivered by incubation end up in lysosomes, a significantly larger proportion of nanostraw-injected FND are in the cytosol, which opens up for using FND as cellular probes. Furthermore, in order to answer the long-standing question in the field of nano-biology regarding the state of the cell membrane on hollow nanostructures, live cell stimulated emission depletion (STED) microscopy is performed to image directly the state of the membrane on nanostraws. The time-lapse STED images reveal that the cell membrane opens entirely on top of nanostraws upon application of gentle electrical pulses, which supports the hypothesis that many FND are delivered directly to the cytosol, avoiding endocytosis and lysosomal entrapment.
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Affiliation(s)
- Elke Hebisch
- Division of Solid State Physics and NanoLund, Lund University, Lund, 221 00, Sweden
| | - Martin Hjort
- Division of Solid State Physics and NanoLund, Lund University, Lund, 221 00, Sweden
- Navan Technologies Inc., 733 Industrial Rd, San Carlos, CA, United States
| | - Diogo Volpati
- Division of Solid State Physics and NanoLund, Lund University, Lund, 221 00, Sweden
| | - Christelle N Prinz
- Division of Solid State Physics and NanoLund, Lund University, Lund, 221 00, Sweden
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22
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Aicher SM, Monaghan P, Netherton CL, Hawes PC. Unpicking the Secrets of African Swine Fever Viral Replication Sites. Viruses 2021; 13:v13010077. [PMID: 33429879 PMCID: PMC7827680 DOI: 10.3390/v13010077] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/30/2020] [Accepted: 01/04/2021] [Indexed: 01/27/2023] Open
Abstract
African swine fever virus (ASFV) is a highly contagious pathogen which causes a lethal haemorrhagic fever in domestic pigs and wild boar. The large, double-stranded DNA virus replicates in perinuclear cytoplasmic replication sites known as viral factories. These factories are complex, multi-dimensional structures. Here we investigated the protein and membrane compartments of the factory using super-resolution and electron tomography. Click IT chemistry in combination with stimulated emission depletion (STED) microscopy revealed a reticular network of newly synthesized viral proteins, including the structural proteins p54 and p34, previously seen as a pleomorphic ribbon by confocal microscopy. Electron microscopy and tomography confirmed that this network is an accumulation of membrane assembly intermediates which take several forms. At early time points in the factory formation, these intermediates present as small, individual membrane fragments which appear to grow and link together, in a continuous progression towards new, icosahedral virions. It remains unknown how these membranes form and how they traffic to the factory during virus morphogenesis.
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Affiliation(s)
- Sophie-Marie Aicher
- African Swine Fever Vaccinology Group, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (S.-M.A.); (C.L.N.)
| | - Paul Monaghan
- Bioimaging, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK;
| | - Christopher L. Netherton
- African Swine Fever Vaccinology Group, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (S.-M.A.); (C.L.N.)
| | - Philippa C. Hawes
- Bioimaging, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK;
- Correspondence:
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Soria FN, Miguelez C, Peñagarikano O, Tønnesen J. Current Techniques for Investigating the Brain Extracellular Space. Front Neurosci 2020; 14:570750. [PMID: 33177979 PMCID: PMC7591815 DOI: 10.3389/fnins.2020.570750] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/17/2020] [Indexed: 12/11/2022] Open
Abstract
The brain extracellular space (ECS) is a continuous reticular compartment that lies between the cells of the brain. It is vast in extent relative to its resident cells, yet, at the same time the nano- to micrometer dimensions of its channels and reservoirs are commonly finer than the smallest cellular structures. Our conventional view of this compartment as largely static and of secondary importance for brain function is rapidly changing, and its active dynamic roles in signaling and metabolite clearance have come to the fore. It is further emerging that ECS microarchitecture is highly heterogeneous and dynamic and that ECS geometry and diffusional properties directly modulate local diffusional transport, down to the nanoscale around individual synapses. The ECS can therefore be considered an extremely complex and diverse compartment, where numerous physiological events are unfolding in parallel on spatial and temporal scales that span orders of magnitude, from milliseconds to hours, and from nanometers to centimeters. To further understand the physiological roles of the ECS and identify new ones, researchers can choose from a wide array of experimental techniques, which differ greatly in their applicability to a given sample and the type of data they produce. Here, we aim to provide a basic introduction to the available experimental techniques that have been applied to address the brain ECS, highlighting their main characteristics. We include current gold-standard techniques, as well as emerging cutting-edge modalities based on recent super-resolution microscopy. It is clear that each technique comes with unique strengths and limitations and that no single experimental method can unravel the unknown physiological roles of the brain ECS on its own.
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Affiliation(s)
- Federico N. Soria
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neuroscience, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Cristina Miguelez
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- Autonomic and Movement Disorders Unit, Neurodegenerative Diseases, Biocruces Health Research Institute, Barakaldo, Spain
| | - Olga Peñagarikano
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Jan Tønnesen
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neuroscience, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
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Rae AE, Wei X, Flores-Rodriguez N, McCurdy DW, Collings DA. Super-Resolution Fluorescence Imaging of Arabidopsis thaliana Transfer Cell Wall Ingrowths using Pseudo-Schiff Labelling Adapted for the Use of Different Dyes. Plant Cell Physiol 2020; 61:1775-1787. [PMID: 32761075 DOI: 10.1093/pcp/pcaa102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/28/2020] [Indexed: 05/23/2023]
Abstract
To understand plant growth and development, it is often necessary to investigate the organization of plant cells and plant cell walls. Plant cell walls are often fluorescently labeled for confocal imaging with the dye propidium iodide using a pseudo-Schiff reaction. This reaction binds free amine groups on dye molecules to aldehyde groups on cellulose that result from oxidation with periodic acid. We tested a range of fluorescent dyes carrying free amine groups for their ability to act as pseudo-Schiff reagents. Using the low-pH solution historically used for the Schiff reaction, these alternative dyes failed to label cell walls of Arabidopsis cotyledon vascular tissue as strongly as propidium iodide but replacing the acidic solution with water greatly improved fluorescence labeling. Under these conditions, rhodamine-123 provided improved staining of plant cell walls compared to propidium iodide. We also developed protocols for pseudo-Schiff labeling with ATTO 647N-amine, a dye compatible for super-resolution Stimulated Emission Depletion (STED) imaging. ATTO 647N-amine was used for super-resolution imaging of cell wall ingrowths that occur in phloem parenchyma transfer cells of Arabidopsis, structures whose small size is only slightly larger than the resolution limit of conventional confocal microscopy. Application of surface-rendering software demonstrated the increase in plasma membrane surface area as a consequence of wall ingrowth deposition and suggests that STED-based approaches will be useful for more detailed morphological analysis of wall ingrowth formation. These improvements in pseudo-Schiff labeling for conventional confocal microscopy and STED imaging will be broadly applicable for high-resolution imaging of plant cell walls.
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Affiliation(s)
- Angus E Rae
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Xiaoyang Wei
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Neftali Flores-Rodriguez
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, NSW 2006, Australia
| | - David W McCurdy
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - David A Collings
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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25
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Lucidi M, Hristu R, Nichele L, Stanciu GA, Tranca DE, Holban AM, Visca P, Stanciu SG, Cincotti G. STED nanoscopy of KK114-stained pathogenic bacteria. J Biophotonics 2020; 13:e202000097. [PMID: 32483852 DOI: 10.1002/jbio.202000097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/11/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Super-resolution microscopy techniques can provide answers to still pending questions on prokaryotic organisms but are yet to be used at their full potential for this purpose. To address this, we evaluate the ability of the rhodamine-like KK114 dye to label various types of bacteria, to enable imaging of fine structural details with stimulated emission depletion microscopy (STED). We assessed fluorescent labeling with KK114 for eleven Gram-positive and Gram-negative bacterial species and observed that this contrast agent binds to their cell membranes. Significant differences in the labeling outputs were noticed across the tested bacterial species, but importantly, KK114-staining allowed the observation of subtle nanometric cell details in some cases. For example, a helix pattern resembling a cytoskeleton arrangement was detected in Bacillus subtilis. Furthermore, we found that KK114 easily penetrates the membrane of bacterial microorganism that lost their viability, which can be useful to discriminate between living and dead cells.
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Affiliation(s)
| | - Radu Hristu
- Center for Microscopy - Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
| | | | - George A Stanciu
- Center for Microscopy - Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
| | - Denis E Tranca
- Center for Microscopy - Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
| | - Alina Maria Holban
- Microbiology and Immunology Department, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Paolo Visca
- Department of Sciences, University Roma Tre, Rome, Italy
| | - Stefan G Stanciu
- Center for Microscopy - Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
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26
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Wang J, Zhang J, Wang L, Gao X, Shao Y, Liu L, Yang Z, Yan W, Qu J. Dual-color STED super-resolution microscope using a single laser source. J Biophotonics 2020; 13:e202000057. [PMID: 32421923 DOI: 10.1002/jbio.202000057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
STED (stimulated emission depletion) microscopy is one of the most promising super-resolution fluorescence microscopies,due to its fast imaging and ultra-high resolution. In this paper, we present a dual-color STED microscope with a single laser source. Polarization beam splitters are used to separate the output from a supercontinuum laser source into four laser beams, including two excitation beams (488, 635 nm) and two depletion beams (592, 775 nm). These four laser beams are then used to build a low cost dual-color STED system to achieve a spatial resolution of 75 nm in cell samples.
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Affiliation(s)
- Jialin Wang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Jia Zhang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Luwei Wang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Xinwei Gao
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Yonghong Shao
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Liwei Liu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Zhigang Yang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Wei Yan
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Junle Qu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
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27
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Chitirala P, Chang HF, Martzloff P, Harenberg C, Ravichandran K, Abdulreda MH, Berggren PO, Krause E, Schirra C, Leinders-Zufall T, Benseler F, Brose N, Rettig J. Studying the biology of cytotoxic T lymphocytes in vivo with a fluorescent granzyme B-mTFP knock-in mouse. eLife 2020; 9:e58065. [PMID: 32696761 PMCID: PMC7375811 DOI: 10.7554/elife.58065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/01/2020] [Indexed: 12/23/2022] Open
Abstract
Understanding T cell function in vivo is of key importance for basic and translational immunology alike. To study T cells in vivo, we developed a new knock-in mouse line, which expresses a fusion protein of granzyme B, a key component of cytotoxic granules involved in T cell-mediated target cell-killing, and monomeric teal fluorescent protein from the endogenous Gzmb locus. Homozygous knock-ins, which are viable and fertile, have cytotoxic T lymphocytes with endogeneously fluorescent cytotoxic granules but wild-type-like killing capacity. Expression of the fluorescent fusion protein allows quantitative analyses of cytotoxic granule maturation, transport and fusion in vitro with super-resolution imaging techniques, and two-photon microscopy in living knock-ins enables the visualization of tissue rejection through individual target cell-killing events in vivo. Thus, the new mouse line is an ideal tool to study cytotoxic T lymphocyte biology and to optimize personalized immunotherapy in cancer treatment.
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Affiliation(s)
- Praneeth Chitirala
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Hsin-Fang Chang
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Paloma Martzloff
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Christiane Harenberg
- Department of Molecular Neurobiology, Max-Planck-Institute of Experimental MedicineGöttingenGermany
| | - Keerthana Ravichandran
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Midhat H Abdulreda
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of MedicineMiamiUnited States
- Department of Surgery, University of Miami Miller School of MedicineMiamiUnited States
- Department of Microbiology and Immunology, University of Miami Miller School of MedicineMiamiUnited States
- Department of Ophthalmology, University of Miami Miller School of MedicineMiamiUnited States
| | - Per-Olof Berggren
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of MedicineMiamiUnited States
- Department of Surgery, University of Miami Miller School of MedicineMiamiUnited States
- Diabetes Research Institute FederationHollywoodUnited States
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University HospitalStockholmSweden
| | - Elmar Krause
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Claudia Schirra
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Trese Leinders-Zufall
- Sensory and Neuroendocrine Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
| | - Fritz Benseler
- Department of Molecular Neurobiology, Max-Planck-Institute of Experimental MedicineGöttingenGermany
| | - Nils Brose
- Department of Molecular Neurobiology, Max-Planck-Institute of Experimental MedicineGöttingenGermany
| | - Jens Rettig
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland UniversityHomburgGermany
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28
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Roy D, Steinkühler J, Zhao Z, Lipowsky R, Dimova R. Mechanical Tension of Biomembranes Can Be Measured by Super Resolution (STED) Microscopy of Force-Induced Nanotubes. Nano Lett 2020; 20:3185-3191. [PMID: 32320255 PMCID: PMC7304919 DOI: 10.1021/acs.nanolett.9b05232] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/20/2020] [Indexed: 05/26/2023]
Abstract
Membrane tension modulates the morphology of plasma-membrane tubular protrusions in cells but is difficult to measure. Here, we propose to use microscopy imaging to assess the membrane tension. We report direct measurement of membrane nanotube diameters with unprecedented resolution using stimulated emission depletion (STED) microscopy. For this purpose, we integrated an optical tweezers setup in a commercial microscope equipped for STED imaging and established micropipette aspiration of giant vesicles. Membrane nanotubes were pulled from the vesicles at specific membrane tension imposed by the aspiration pipet. Tube diameters calculated from the applied tension using the membrane curvature elasticity model are in excellent agreement with data measured directly with STED. Our approach can be extended to cellular membranes and will then allow us to estimate the mechanical membrane tension within the force-induced nanotubes.
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29
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Wirth R, Gao P, Nienhaus GU, Sunbul M, Jäschke A. Confocal and Super-resolution Imaging of RNA in Live Bacteria Using a Fluorogenic Silicon Rhodamine-binding Aptamer. Bio Protoc 2020; 10:e3603. [PMID: 33659569 DOI: 10.21769/bioprotoc.3603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/15/2020] [Accepted: 02/13/2020] [Indexed: 12/15/2022] Open
Abstract
Genetically encoded light-up RNA aptamers have been shown to be promising tools for the visualization of RNAs in living cells, helping us to advance our understanding of the broad and complex life of RNA. Although a handful of light-up aptamers spanning the visible wavelength region have been developed, none of them have yet been reported to be compatible with advanced super-resolution techniques, mainly due to poor photophysical properties of their small-molecule fluorogens. Here, we describe a detailed protocol for fluorescence microscopy of mRNA in live bacteria using the recently reported fluorogenic silicon rhodamine binding aptamer (SiRA) featuring excellent photophysical properties. Notably, with SiRA, we demonstrated the first aptamer-based RNA visualization using super-resolution (STED) microscopy. This imaging method can be especially valuable for visualization of RNA in prokaryotes since the size of a bacterium is only a few times greater than the optical resolution of a conventional microscope.
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Affiliation(s)
- Regina Wirth
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
| | - Peng Gao
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Str. 1, 76131 Karlsruhe, Germany.,Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - G Ulrich Nienhaus
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Str. 1, 76131 Karlsruhe, Germany.,Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Murat Sunbul
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
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Sharma R, Singh M, Sharma R. Recent advances in STED and RESOLFT super-resolution imaging techniques. Spectrochim Acta A Mol Biomol Spectrosc 2020; 231:117715. [PMID: 31748155 DOI: 10.1016/j.saa.2019.117715] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/15/2019] [Accepted: 10/26/2019] [Indexed: 06/10/2023]
Abstract
Stimulated emission depletion (STED) and reversible saturable optical fluorescence transition (RESOLFT) microscopy are the super-resolution imaging techniques that can acquire nanoscale spatial resolution. The spatial resolution of the other far-field optical microscopic techniques is bound by diffraction limit, however, STED/RESOLFT techniques eliminate the diffraction barrier. These microscopic techniques have taken the limits of optical image resolution down to the nanometer scale and opened new paths for biomedical and nanophosphor research. In this paper, we review the recent advancements of these techniques in the field of nanoscopy using continuous wave (CW) laser sources. Further, we discuss the main limitation of the STED microscopy in terms of essential requirements of higher depletion beam power and photobleaching issues. The RESOLFT microscopic technique can be considered as an alternate technique to overcome limitations of existing STED microscopy. Moreover, the Bessel and Gaussian-Bessel beam STED microscopic techniques are also reviewed to produce deep images with faster scanning of the samples. The organic molecules as well as the fluorescent doped nanoparticles like ZnSe:Mn having characteristics of excited state absorption can be investigated using RESOLFT microscopy.
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Affiliation(s)
- Reena Sharma
- Department of Physics, University Institute of Sciences, Chandigarh University, Mohali, Punjab, 140413, India
| | - Manjot Singh
- Department of Physics, University Institute of Sciences, Chandigarh University, Mohali, Punjab, 140413, India
| | - Rajesh Sharma
- Department of Physics, University Institute of Sciences, Chandigarh University, Mohali, Punjab, 140413, India.
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31
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Frutos-Grilo E, Marsal M, Irazoki O, Barbé J, Campoy S. The Interaction of RecA With Both CheA and CheW Is Required for Chemotaxis. Front Microbiol 2020; 11:583. [PMID: 32318049 PMCID: PMC7154110 DOI: 10.3389/fmicb.2020.00583] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/17/2020] [Indexed: 12/20/2022] Open
Abstract
Salmonella enterica is the most frequently reported cause of foodborne illness. As in other microorganisms, chemotaxis affords key physiological benefits, including enhanced access to growth substrates, but also plays an important role in infection and disease. Chemoreceptor signaling core complexes, consisting of CheA, CheW and methyl-accepting chemotaxis proteins (MCPs), modulate the switching of bacterial flagella rotation that drives cell motility. These complexes, through the formation of heterohexameric rings composed of CheA and CheW, form large clusters at the cell poles. RecA plays a key role in polar cluster formation, impairing the assembly when the SOS response is activated. In this study, we determined that RecA protein interacts with both CheW and CheA. The binding of these proteins to RecA is needed for wild-type polar cluster formation. In silico models showed that one RecA molecule, attached to one signaling unit, fits within a CheA-CheW ring without interfering with the complex formation or array assembly. Activation of the SOS response is followed by an increase in RecA, which rises up the number of signaling complexes associated with this protein. This suggests the presence of allosteric inhibition in the CheA-CheW interaction and thus of heterohexameric ring formation, impairing the array assembly. STED imaging demonstrated that all core unit components (CheA, CheW, and MPCs) have the same subcellular location as RecA. Activation of the SOS response promotes the RecA distribution along the cell instead of being at the cell poles. CheA- and CheW- RecA interactions are also crucial for chemotaxis, which is maintained when the SOS response is induced and the signaling units are dispersed. Our results provide new molecular-level insights into the function of RecA in chemoreceptor clustering and chemotaxis determining that the impaired chemoreceptor clustering not only inhibits swarming but also modulates chemotaxis in SOS-induced cells, thereby modifying bacterial motility in the presence of DNA-damaging compounds, such as antibiotics.
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Affiliation(s)
- Elisabet Frutos-Grilo
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Maria Marsal
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Oihane Irazoki
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jordi Barbé
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Susana Campoy
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
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Németh E, Knorr G, Németh K, Kele P. A Bioorthogonally Applicable, Fluorogenic, Large Stokes-Shift Probe for Intracellular Super-Resolution Imaging of Proteins. Biomolecules 2020; 10:biom10030397. [PMID: 32143419 PMCID: PMC7175155 DOI: 10.3390/biom10030397] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 02/28/2020] [Accepted: 03/01/2020] [Indexed: 01/02/2023] Open
Abstract
Herein, we present the synthesis and application of a fluorogenic, large Stokes-shift (>100 nm), bioorthogonally conjugatable, membrane-permeable tetrazine probe, which can be excited at common laser line 488 nm and detected at around 600 nm. The applied design enabled improved fluorogenicity in the orange/red emission range, thus efficient suppression of background and autofluorescence upon imaging biological samples. Moreover, unlike our previous advanced probes, it does not require the presence of special target platforms or microenvironments to achieve similar fluorogenicity and can be generally applied, e.g., on translationally bioorthogonalized proteins. Live-cell labeling schemes revealed that the fluorogenic probe is suitable for specific labeling of intracellular proteins, site-specifically modified with a cyclooctynylated, non-canonical amino acid, even under no-wash conditions. Furthermore, the probe was found to be applicable in stimulated emission depletion (STED) super-resolution microscopy imaging using a 660 nm depletion laser. Probably the most salient feature of this new probe is that the large Stokes-shift allows dual-color labeling schemes of cellular structures using distinct excitation and the same detection wavelengths for the combined probes, which circumvents chromatic aberration related problems.
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33
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Gao Z, Wang JH, Song P, Kang B, Xu JJ, Chen HY. Spaser Nanoparticles for Ultranarrow Bandwidth STED Super-Resolution Imaging. Adv Mater 2020; 32:e1907233. [PMID: 31957100 DOI: 10.1002/adma.201907233] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/02/2019] [Indexed: 06/10/2023]
Abstract
Super-resolution microscopy, as a powerful tool of seeing abundant spatial details, typically can only distinguish a few distinct targets at a time due to the spectral crosstalk between fluorophores. Spaser (i.e., surface plasmon laser) nanoprobes, which confine lasing emission into nanoscale, offer an opportunity to eliminate such obstacle. Here, realized is narrow band stimulated emission depletion (STED) nanoscopy on spaser nanoparticles by collecting the coherent spasing signals. Demonstrated are the physics concept and feasibility of erasing spaser emission by using a depletion beam to suppress the population inversion, which lays the foundation of spaser-based STED super-resolution. Thanks to the small size (47 nm) and narrow spectral linewidth (3.8 nm) of the spaser nanoparticles, a 74 nm spatial resolution in STED imaging within an acquisition bandwidth of 10 nm is finally obtained. These spaser nanoparticles, if multiplexing with different wavelengths, in principle, allow for spectral-multiplexed imaging, sensing, cytometry, and light operation of a large number of targets all at once.
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Affiliation(s)
- Zhaoshuai Gao
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Jian-Hua Wang
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Pei Song
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Bin Kang
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Jing-Juan Xu
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Hong-Yuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
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34
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Zdańkowski P, Trusiak M, McGloin D, Swedlow JR. Numerically Enhanced Stimulated Emission Depletion Microscopy with Adaptive Optics for Deep-Tissue Super-Resolved Imaging. ACS Nano 2020; 14:394-405. [PMID: 31841303 DOI: 10.1021/acsnano.9b05891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In stimulated emission depletion (STED) nanoscopy, the major origin of decreased signal-to-noise ratio within images can be attributed to sample photobleaching and strong optical aberrations. This is due to STED utilizing a high-power depletion laser (increasing the risk of photodamage), while the depletion beam is very sensitive to sample-induced aberrations. Here, we demonstrate a custom-built STED microscope with automated aberration correction that is capable of 3D super-resolution imaging through thick, highly aberrating tissue. We introduce and investigate a state of the art image denoising method by block-matching and collaborative 3D filtering (BM3D) to numerically enhance fine object details otherwise mixed with noise and further enhance the image quality. Numerical denoising provides an increase in the final effective resolution of the STED imaging of 31% using the well established Fourier ring correlation metric. Results achieved through the combination of aberration correction and tailored image processing are experimentally validated through super-resolved 3D imaging of axons in differentiated induced pluripotent stem cells growing under an 80 μm thick layer of tissue with lateral and axial resolution of 204 and 310 nm, respectively.
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Affiliation(s)
- Piotr Zdańkowski
- Centre for Gene Regulation and Expression, School of Life Sciences , University of Dundee , Dundee DD1 5EH , United Kingdom
- SUPA, School of Science and Engineering , University of Dundee , Dundee DD1 4HN , United Kingdom
- Institute of Micromechanics and Photonics , Warsaw University of Technology , 8 A. Boboli Street , Warsaw 02-525 , Poland
| | - Maciej Trusiak
- Institute of Micromechanics and Photonics , Warsaw University of Technology , 8 A. Boboli Street , Warsaw 02-525 , Poland
| | - David McGloin
- SUPA, School of Science and Engineering , University of Dundee , Dundee DD1 4HN , United Kingdom
- School of Electrical and Data Engineering , University of Technology Sydney , Ultimo , New South Wales 2007 , Australia
| | - Jason R Swedlow
- Centre for Gene Regulation and Expression, School of Life Sciences , University of Dundee , Dundee DD1 5EH , United Kingdom
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35
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Abstract
We recently discovered that peptide dendrimers such as G3KL ((KL)8(KKL)4(KKL)2KKL, K = branching l-lysine) exert strong activity against Gram-negative bacteria including Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. Herein, we report a detailed mechanistic study using fluorescence labeled analogs bearing fluorescein (G3KL-Fluo) or dansyl (G3KL-Dansyl), which show a similar bioactivity profile as G3KL. Imaging bacterial killing by super-resolution stimulated emission depletion (STED) microscopy, time-lapse imaging, and transmission electron microscopy (TEM) reveals that the dendrimer localizes at the bacterial membrane, induces membrane depolarization and permeabilization, and destroys the outer leaflet and the inner membrane. G3KL accumulates in bacteria against which it is active; however, it only weakly penetrates into eukaryotic cells without inducing significant toxicity. G3KL furthermore binds to lipopolysaccharide (LPS) and inhibits the LPS induced release of TNF-α by macrophages, similarly to polymyxin B. Taken together, these experiments show that G3KL behaves as a potent membrane disruptive antimicrobial peptide.
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Affiliation(s)
- Bee-Ha Gan
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Thissa N. Siriwardena
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Sacha Javor
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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36
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Rudolph F, Hüttemeister J, da Silva Lopes K, Jüttner R, Yu L, Bergmann N, Friedrich D, Preibisch S, Wagner E, Lehnart SE, Gregorio CC, Gotthardt M. Resolving titin's lifecycle and the spatial organization of protein turnover in mouse cardiomyocytes. Proc Natl Acad Sci U S A 2019; 116:25126-36. [PMID: 31757849 DOI: 10.1073/pnas.1904385116] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cardiac protein homeostasis, sarcomere assembly, and integration of titin as the sarcomeric backbone are tightly regulated to facilitate adaptation and repair. Very little is known on how the >3-MDa titin protein is synthesized, moved, inserted into sarcomeres, detached, and degraded. Here, we generated a bifluorescently labeled knockin mouse to simultaneously visualize both ends of the molecule and follow titin's life cycle in vivo. We find titin mRNA, protein synthesis and degradation compartmentalized toward the Z-disk in adult, but not embryonic cardiomyocytes. Originating at the Z-disk, titin contributes to a soluble protein pool (>15% of total titin) before it is integrated into the sarcomere lattice. Titin integration, disintegration, and reintegration are stochastic and do not proceed sequentially from Z-disk to M-band, as suggested previously. Exchange between soluble and integrated titin depends on titin protein composition and differs between individual cardiomyocytes. Thus, titin dynamics facilitate embryonic vs. adult sarcomere remodeling with implications for cardiac development and disease.
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37
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Spahn C, Hurter F, Glaesmann M, Karathanasis C, Lampe M, Heilemann M. Protein-Specific, Multicolor and 3D STED Imaging in Cells with DNA-Labeled Antibodies. Angew Chem Int Ed Engl 2019; 58:18835-18838. [PMID: 31603612 PMCID: PMC6972974 DOI: 10.1002/anie.201910115] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/25/2019] [Indexed: 12/21/2022]
Abstract
Photobleaching is a major challenge in fluorescence microscopy, in particular if high excitation light intensities are used. Signal‐to‐noise and spatial resolution may be compromised, which limits the amount of information that can be extracted from an image. Photobleaching can be bypassed by using exchangeable labels, which transiently bind to and dissociate from a target, thereby replenishing the destroyed labels with intact ones from a reservoir. Here, we demonstrate confocal and STED microscopy with short, fluorophore‐labeled oligonucleotides that transiently bind to complementary oligonucleotides attached to protein‐specific antibodies. The constant exchange of fluorophore labels in DNA‐based STED imaging bypasses photobleaching that occurs with covalent labels. We show that this concept is suitable for targeted, two‐color STED imaging of whole cells.
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Affiliation(s)
- Christoph Spahn
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt, Germany
| | | | - Mathilda Glaesmann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt, Germany
| | - Christos Karathanasis
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt, Germany
| | - Marko Lampe
- Advanced Light Microscopy Facility, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117, Heidelberg, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt, Germany
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Lim G, Kim WC, Oh S, Lee H, Park NC. Enhanced lateral resolution in continuous wave stimulated emission depletion microscopy using tightly focused annular radially polarized excitation beam. J Biophotonics 2019; 12:e201900060. [PMID: 31050861 DOI: 10.1002/jbio.201900060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 06/09/2023]
Abstract
The lateral resolution of continuous wave (CW) stimulated emission depletion (STED) microscopy is enhanced about 12% by applying annular-shaped amplitude modulation to the radially polarized excitation beam. A focused annularly filtered radially polarized excitation beam provides a more condensed point spread function (PSF), which contributes to enhance effective STED resolution of CW STED microscopy. Theoretical analysis shows that the FWHM of the effective PSF on the detection plane is smaller than for conventional CW STED. Simulation shows the donut-shaped PSF of the depletion beam and confocal optics suppress undesired PSF sidelobes. Imaging experiments agree with the simulated resolution improvement.
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Affiliation(s)
- Geon Lim
- School of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea
| | - Wan-Chin Kim
- Department of Smart Manufacturing Applied Engineering, Hanbat National University, Daejeon, Republic of Korea
| | - Seunghee Oh
- School of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea
- Global Technology Center, Samsung Electronics, Suwon, Republic of Korea
| | - Hyungsuk Lee
- School of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea
| | - No-Cheol Park
- School of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea
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39
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Wang C, Taki M, Sato Y, Tamura Y, Yaginuma H, Okada Y, Yamaguchi S. A photostable fluorescent marker for the superresolution live imaging of the dynamic structure of the mitochondrial cristae. Proc Natl Acad Sci U S A 2019; 116:15817-22. [PMID: 31337683 DOI: 10.1073/pnas.1905924116] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Stimulation emission depletion (STED) microscopy enables ultrastructural imaging of organelle dynamics with a high spatiotemporal resolution in living cells. For the visualization of the mitochondrial membrane dynamics in STED microscopy, rationally designed mitochondrial fluorescent markers with enhanced photostability are required. Herein, we report the development of a superphotostable fluorescent labeling reagent with long fluorescence lifetime, whose design is based on a structurally reinforced naphthophosphole fluorophore that is conjugated with an electron-donating diphenylamino group. The combination of long-lived fluorescence and superphotostable features of the fluorophore allowed us to selectively capture the ultrastructures of the mitochondrial cristae with a resolution of ∼60 nm when depleted at 660 nm. This chemical tool provides morphological information of the cristae, which has so far only been observed in fixed cells using electron microscopy. Moreover, this method gives information about the dynamic ultrastructures such as the intermembrane fusion in different mitochondria as well as the intercristae mergence in a single mitochondrion during the apoptosis-like mitochondrial swelling process.
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40
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Combs CA, Sackett DL, Knutson JR. A simple empirical algorithm for optimising depletion power and resolution for dye and system specific STED imaging. J Microsc 2019; 274:168-176. [PMID: 31012103 DOI: 10.1111/jmi.12795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 11/28/2022]
Abstract
Here we show an easy method for determining an effective dye saturation factor ('PSTED ') for STED (Stimulated Emission Depletion) microscopy. We define PSTED to be a combined microscope system plus dye factor (analogous to the traditional ground truth Is measurement, which is microscope independent) that is functionally defined as the power in the depletion beam that provides a resolution enhancement of 41% compared to confocal, according to the modified Abbe's formula for STED resolution enhancement. We show that the determination of PSTED provides insight not only into the suitability of a particular dye and the best imaging parameters to be used for an experiment, but also sets the critical value for correctly determining the point spread function (PSF) used in deconvolution of STED images. PSTED can be a function of many experimental variables, both microscope and sample related. Here we show the utility of doing PSTED determinations by (1) exploiting the simple relationship between width and a threshold-defined area provided by a Gaussian PSF, for either linear or spherical objects and (2) linearising the normally inverse hyperbolic function of resolution versus power that can determine PSTED . We show that this rearrangement allows us to determine PSTED using only a few measurements: either at a few relatively low depletion powers, on traditional bead size measurements or by finding the total area of a naturally occurring sub-limit sized biological feature (in this case, microtubules). We show the derivation of these equations and methods and the utility of its use by characterising several dyes and a local imaging parameter relevant to STED microscopy. This information is used to predict the enhancement of resolution of the point spread function necessary for post-processing deconvolution. LAY DESCRIPTION: Stimulated Emission Depletion (STED) microscopy is a fluorescence imaging superresolution technique that achieves tens of nanometres resolution. This is done by utilising a depletion laser to effectively quench (deplete) fluorescence in a donut shape overlapping the normally excited fluorescence spot. The size of the remaining (undepleted) central fluorescence spot is power dependent allowing 'tunable' resolution with the power of the STED depletion laser. This depletion power versus resolution relationship is dye and instrument dependent. We have developed a method for quickly measuring this relationship to optimise experiments based on individual dyes and microscope specific parameters. This allows for quickly optimising microscope settings and for correctly postprocessing images.
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Affiliation(s)
- Christian A Combs
- NHLBI Light Microscopy Facility, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Dan L Sackett
- NICHD Division of Basic and Translational Biophysics, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Jay R Knutson
- NHLBI Laboratory for Advanced Microscopy and Biophotonics, National Institutes of Health, Bethesda, Maryland, U.S.A
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41
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Lichnog C, Klabunde S, Becker E, Fuh F, Tripal P, Atreya R, Klenske E, Erickson R, Chiu H, Reed C, Chung S, Neufert C, Atreya I, McBride J, Neurath MF, Zundler S. Cellular Mechanisms of Etrolizumab Treatment in Inflammatory Bowel Disease. Front Pharmacol 2019; 10:39. [PMID: 30774593 PMCID: PMC6367223 DOI: 10.3389/fphar.2019.00039] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/14/2019] [Indexed: 12/26/2022] Open
Abstract
Background: Anti-integrin therapy is a new frontline strategy in the treatment of inflammatory bowel diseases (IBD). The anti-β7 integrin antibody etrolizumab is currently being investigated for safety and efficacy in Crohn’s disease (CD) and ulcerative colitis (UC) in several phase III trials. Mechanistically, etrolizumab is known to block β7 integrin ligand binding and reduces intestinal trafficking of β7-expressing cells. Etrolizumab blocks β7 integrin ligand binding and reduces β7-positive lymphocyte migration and retention in the inflamed gut mucosa, but the exact mechanisms by which this inhibition occurs are not fully understood. Methods: Cellular effects of etrolizumab or etrolizumab surrogate antibody (etrolizumab-s) were investigated in cell culture models and analyzed by flow cytometry, fluorescence microscopy, ImageStream®, stimulated emission depletion (STED) microscopy and functional dynamic in vitro adhesion assays. Moreover, effects on α4β7 integrin were compared with the pharmacodynamically similar antibody vedolizumab. Results: As demonstrated by several different approaches, etrolizumab and etrolizumab-s treatment led to internalization of β7 integrin. This resulted in impaired dynamic adhesion to MAdCAM-1. Internalized β7 integrin localized in endosomes and re-expression of β7 was dependent on de novo protein synthesis. In vitro etrolizumab treatment did not lead to cellular activation or cytokine secretion and did not induce cytotoxicity. Internalization of α4β7 integrin was increased with etrolizumab compared with vedolizumab. Discussion: Our data suggest that etrolizumab does not elicit secondary effector functions on the single cell level. Integrin internalization may be an important mechanism of action of etrolizumab, which might explain some but not all immunological effects observed with etrolizumab.
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Affiliation(s)
- Charlotte Lichnog
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Sha Klabunde
- OMNI Biomarker Development, Development Sciences, Genentech, Inc., South San Francisco, CA, United States
| | - Emily Becker
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Franklin Fuh
- OMNI Biomarker Development, Development Sciences, Genentech, Inc., South San Francisco, CA, United States
| | - Philipp Tripal
- Optical Imaging Centre, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Raja Atreya
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Entcho Klenske
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Rich Erickson
- BioAnalytical Sciences, Development Sciences, Genentech, Inc., South San Francisco, CA, United States
| | - Henry Chiu
- Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA, United States
| | - Chae Reed
- BioAnalytical Sciences, Development Sciences, Genentech, Inc., South San Francisco, CA, United States
| | - Shan Chung
- BioAnalytical Sciences, Development Sciences, Genentech, Inc., South San Francisco, CA, United States
| | - Clemens Neufert
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Imke Atreya
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Jacqueline McBride
- OMNI Biomarker Development, Development Sciences, Genentech, Inc., South San Francisco, CA, United States
| | - Markus F Neurath
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
| | - Sebastian Zundler
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Kussmaul Campus for Medical Research and Translational Research Center, Erlangen, Germany
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42
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Lindner M, Tresztenyak A, Fülöp G, Jahr W, Prinz A, Prinz I, Danzl JG, Schütz GJ, Sevcsik E. A Fast and Simple Contact Printing Approach to Generate 2D Protein Nanopatterns. Front Chem 2019; 6:655. [PMID: 30733939 PMCID: PMC6353799 DOI: 10.3389/fchem.2018.00655] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/17/2018] [Indexed: 01/02/2023] Open
Abstract
Protein micropatterning has become an important tool for many biomedical applications as well as in academic research. Current techniques that allow to reduce the feature size of patterns below 1 μm are, however, often costly and require sophisticated equipment. We present here a straightforward and convenient method to generate highly condensed nanopatterns of proteins without the need for clean room facilities or expensive equipment. Our approach is based on nanocontact printing and allows for the fabrication of protein patterns with feature sizes of 80 nm and periodicities down to 140 nm. This was made possible by the use of the material X-poly(dimethylsiloxane) (X-PDMS) in a two-layer stamp layout for protein printing. In a proof of principle, different proteins at various scales were printed and the pattern quality was evaluated by atomic force microscopy (AFM) and super-resolution fluorescence microscopy.
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Affiliation(s)
- Marco Lindner
- Institute of Applied Physics, TU Wien, Vienna, Austria
- Stratec Consumables GmbH, Anif, Austria
| | | | - Gergö Fülöp
- Institute of Applied Physics, TU Wien, Vienna, Austria
| | - Wiebke Jahr
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | | | - Johann G. Danzl
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | - Eva Sevcsik
- Institute of Applied Physics, TU Wien, Vienna, Austria
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43
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Stahlberg MA, Ramakrishnan C, Willig KI, Boyden ES, Deisseroth K, Dean C. Investigating the feasibility of channelrhodopsin variants for nanoscale optogenetics. Neurophotonics 2019; 6:015007. [PMID: 30854405 PMCID: PMC6393647 DOI: 10.1117/1.nph.6.1.015007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Optogenetics has revolutionized the study of circuit function in the brain, by allowing activation of specific ensembles of neurons by light. However, this technique has not yet been exploited extensively at the subcellular level. Here, we test the feasibility of a focal stimulation approach using stimulated emission depletion/reversible saturable optical fluorescence transitions-like illumination, whereby switchable light-gated channels are focally activated by a laser beam of one wavelength and deactivated by an overlapping donut-shaped beam of a different wavelength, confining activation to a center focal region. This method requires that activated channelrhodopsins are inactivated by overlapping illumination of a distinct wavelength and that photocurrents are large enough to be detected at the nanoscale. In tests of current optogenetic tools, we found that ChR2 C128A/H134R/T159C and CoChR C108S and C108S/D136A-activated with 405-nm light and inactivated by coillumination with 594-nm light-and C1V1 E122T/C167S-activated by 561-nm light and inactivated by 405-nm light-were most promising in terms of highest photocurrents and efficient inactivation with coillumination. Although further engineering of step-function channelrhodopsin variants with higher photoconductances will be required to employ this approach at the nanoscale, our findings provide a framework to guide future development of this technique.
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Affiliation(s)
- Markus A. Stahlberg
- European Neuroscience Institute, Trans-Synaptic Signaling Group, Goettingen, Germany
| | - Charu Ramakrishnan
- Stanford University, Howard Hughes Medical Institute, Department of Bioengineering, Department of Psychiatry, CNC Program, Stanford, California, United States
| | - Katrin I. Willig
- University Medical Center, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
| | - Edward S. Boyden
- MIT Media Lab and McGovern Institute, Departments of Brain and Cognitive Science and Biological Engineering, Cambridge, Massachusetts, United States
| | - Karl Deisseroth
- Stanford University, Howard Hughes Medical Institute, Department of Bioengineering, Department of Psychiatry, CNC Program, Stanford, California, United States
| | - Camin Dean
- European Neuroscience Institute, Trans-Synaptic Signaling Group, Goettingen, Germany
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44
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Urbančič I, Garvas M, Kokot B, Majaron H, Umek P, Cassidy H, Škarabot M, Schneider F, Galiani S, Arsov Z, Koklic T, Matallanas D, Čeh M, Muševič I, Eggeling C, Štrancar J. Nanoparticles Can Wrap Epithelial Cell Membranes and Relocate Them Across the Epithelial Cell Layer. Nano Lett 2018; 18:5294-5305. [PMID: 30039976 PMCID: PMC6089500 DOI: 10.1021/acs.nanolett.8b02291] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/24/2018] [Indexed: 06/08/2023]
Abstract
Although the link between the inhalation of nanoparticles and cardiovascular disease is well established, the causal pathway between nanoparticle exposure and increased activity of blood coagulation factors remains unexplained. To initiate coagulation tissue factor bearing epithelial cell membranes should be exposed to blood, on the other side of the less than a micrometre thin air-blood barrier. For the inhaled nanoparticles to promote coagulation, they need to bind lung epithelial-cell membrane parts and relocate them into the blood. To assess this hypothesis, we use advanced microscopy and spectroscopy techniques to show that the nanoparticles wrap themselves with epithelial-cell membranes, leading to the membrane's disruption. The membrane-wrapped nanoparticles are then observed to freely diffuse across the damaged epithelial cell layer relocating epithelial cell membrane parts over the epithelial layer. Proteomic analysis of the protein content in the nanoparticles wraps/corona finally reveals the presence of the coagulation-initiating factors, supporting the proposed causal link between the inhalation of nanoparticles and cardiovascular disease.
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Affiliation(s)
- Iztok Urbančič
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Weatherall
Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3
9DS, United Kingdom
| | - Maja Garvas
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Jožef
Stefan International Postgraduate School, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Boštjan Kokot
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Hana Majaron
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Polona Umek
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Center
of Excellence NAMASTE, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Hilary Cassidy
- Systems
Biology Ireland, University College Dublin, Dublin 4, Ireland
| | - Miha Škarabot
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Falk Schneider
- Weatherall
Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3
9DS, United Kingdom
| | - Silvia Galiani
- Weatherall
Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3
9DS, United Kingdom
| | - Zoran Arsov
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Center
of Excellence NAMASTE, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Tilen Koklic
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Center
of Excellence NAMASTE, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - David Matallanas
- Systems
Biology Ireland, University College Dublin, Dublin 4, Ireland
- School of
Medicine and Medical Science, University
College Dublin, Dublin 4, Ireland
| | - Miran Čeh
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Igor Muševič
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska
19, SI-1000 Ljubljana, Slovenia
| | - Christian Eggeling
- Weatherall
Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3
9DS, United Kingdom
- Institute
of Applied Optics, Friedrich-Schiller University, Jena 07749, Germany
- Leibniz
Institute of Photonic Technology (IPHT), Jena 07745, Germany
| | - Janez Štrancar
- “Jožef
Stefan Institute”, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Center
of Excellence NAMASTE, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
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45
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Abstract
Together with endothelial cells and the glomerular basement membrane, podocytes form the size-specific filtration barrier of the glomerulus with their interdigitating foot processes. Since glomerulopathies are associated with so-called foot process effacement-a severe change of well-formed foot processes into flat and broadened processes-visualization of the three-dimensional podocyte morphology is a crucial part for diagnosis of nephrotic diseases. However, interdigitating podocyte foot processes are too narrow to be resolved by classic light microscopy due to Ernst Abbe's law making electron microscopy necessary. Although three dimensional electron microscopy approaches like serial block face and focused ion beam scanning electron microscopy and electron tomography allow volumetric reconstruction of podocytes, these techniques are very time-consuming and too specialized for routine use or screening purposes. During the last few years, different super-resolution microscopic techniques were developed to overcome the optical resolution limit enabling new insights into podocyte morphology. Super-resolution microscopy approaches like three dimensional structured illumination microscopy (3D-SIM), stimulated emission depletion microscopy (STED) and localization microscopy [stochastic optical reconstruction microscopy (STORM), photoactivated localization microscopy (PALM)] reach resolutions down to 80-20 nm and can be used to image and further quantify podocyte foot process morphology. Furthermore, in vivo imaging of podocytes is essential to study the behavior of these cells in situ. Therefore, multiphoton laser microscopy was a breakthrough for in vivo studies of podocytes in transgenic animal models like rodents and zebrafish larvae because it allows imaging structures up to several hundred micrometer in depth within the tissue. Additionally, along with multiphoton microscopy, lightsheet microscopy is currently used to visualize larger tissue volumes and therefore image complete glomeruli in their native tissue context. Alongside plain visualization of cellular structures, atomic force microscopy has been used to study the change of mechanical properties of podocytes in diseased states which has been shown to be a culprit in podocyte maintenance. This review discusses recent advances in the field of microscopic imaging and demonstrates their currently used and other possible applications for podocyte research.
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Affiliation(s)
| | | | - Nicole Endlich
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
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46
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Nicolas JD, Bernhardt M, Schlick SF, Tiburcy M, Zimmermann WH, Khan A, Markus A, Alves F, Toischer K, Salditt T. X-ray diffraction imaging of cardiac cells and tissue. Prog Biophys Mol Biol 2018; 144:151-165. [PMID: 29914693 DOI: 10.1016/j.pbiomolbio.2018.05.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/18/2018] [Accepted: 05/25/2018] [Indexed: 12/30/2022]
Abstract
With the development of advanced focusing optics for x-rays, we can now use x-ray beams with spot sizes in the micro- or nanometer range to scan cells and large areas of tissues and continuously record the diffraction signals. From this data, x-ray scattering maps or so-called x-ray darkfield images are computed showing how different types of cells or regions of tissues differ in their diffraction intensity. At the same time a diffraction pattern is available for each scan point which encodes the local nanostructure, averaged over many contributing constituents illuminated by the beam. In this work we have exploited these new capabilities of scanning x-ray diffraction to investigate cardiac muscle cells as well as cardiac tissue. We give examples of how cardiac cells, especially living, cultured cells, can be prepared to be compatible with the instrumentation constraints of nano- or micro-diffraction instruments. Furthermore, we show how the developmental stage, ranging from neonatal to adult cells, as well as the final preparation state of the cardiomyocytes influences the recorded scattering signal and how these diffraction signals compare to the structure of a fully developed cardiac muscle.
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Affiliation(s)
- Jan-David Nicolas
- Universität Göttingen, Institut für Röntgenphysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Marten Bernhardt
- Universität Göttingen, Institut für Röntgenphysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Susanne F Schlick
- Universitätsmedizin Göttingen, Institut für Pharmakologie und Toxikologie, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Malte Tiburcy
- Universitätsmedizin Göttingen, Institut für Pharmakologie und Toxikologie, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Wolfram-Hubertus Zimmermann
- Universitätsmedizin Göttingen, Institut für Pharmakologie und Toxikologie, Robert-Koch-Str. 40, 37075 Göttingen, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Oudenarder Straße 16, 13347 Berlin, Germany
| | - Amara Khan
- Max-Planck-Institut für Experimentelle Medizin, Hermann-Rein-Straße 3, 37075 Göttingen, Germany; Universitätsmedizin Göttingen, Institut für Diagnostische und Interventionelle Radiologie, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Andrea Markus
- Max-Planck-Institut für Experimentelle Medizin, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Frauke Alves
- Max-Planck-Institut für Experimentelle Medizin, Hermann-Rein-Straße 3, 37075 Göttingen, Germany; Universitätsmedizin Göttingen, Institut für Diagnostische und Interventionelle Radiologie, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Karl Toischer
- Universitätsmedizin Göttingen, Klinik für Kardiologie und Pneumologie, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Tim Salditt
- Universität Göttingen, Institut für Röntgenphysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
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Reina F, Galiani S, Shrestha D, Sezgin E, de Wit G, Cole D, Christoffer Lagerholm B, Kukura P, Eggeling C. Complementary studies of lipid membrane dynamics using iSCAT and super-resolved fluorescence correlation spectroscopy. J Phys D Appl Phys 2018; 51:235401. [PMID: 29853718 PMCID: PMC5964363 DOI: 10.1088/1361-6463/aac04f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/12/2018] [Accepted: 04/26/2018] [Indexed: 05/20/2023]
Abstract
Observation techniques with high spatial and temporal resolution, such as single-particle tracking based on interferometric scattering (iSCAT) microscopy, and fluorescence correlation spectroscopy applied on a super-resolution STED microscope (STED-FCS), have revealed new insights of the molecular organization of membranes. While delivering complementary information, there are still distinct differences between these techniques, most prominently the use of fluorescent dye tagged probes for STED-FCS and a need for larger scattering gold nanoparticle tags for iSCAT. In this work, we have used lipid analogues tagged with a hybrid fluorescent tag-gold nanoparticle construct, to directly compare the results from STED-FCS and iSCAT measurements of phospholipid diffusion on a homogeneous supported lipid bilayer (SLB). These comparative measurements showed that while the mode of diffusion remained free, at least at the spatial (>40 nm) and temporal (50 ⩽ t ⩽ 100 ms) scales probed, the diffussion coefficient was reduced by 20- to 60-fold when tagging with 20 and 40 nm large gold particles as compared to when using dye tagged lipid analogues. These FCS measurements of hybrid fluorescent tag-gold nanoparticle labeled lipids also revealed that commercially supplied streptavidin-coated gold nanoparticles contain large quantities of free streptavidin. Finally, the values of apparent diffusion coefficients obtained by STED-FCS and iSCAT differed by a factor of 2-3 across the techniques, while relative differences in mobility between different species of lipid analogues considered were identical in both approaches. In conclusion, our experiments reveal that large and potentially cross-linking scattering tags introduce a significant slow-down in diffusion on SLBs but no additional bias, and our labeling approach creates a new way of exploiting complementary information from STED-FCS and iSCAT measurements.
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Affiliation(s)
- Francesco Reina
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Silvia Galiani
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Dilip Shrestha
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Erdinc Sezgin
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Gabrielle de Wit
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Daniel Cole
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - B Christoffer Lagerholm
- Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Institute of Applied Optics, Friedrich-Schiller University, Jena, Germany
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
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48
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Henriet E, Sala M, Abou Hammoud A, Tuariihionoa A, Di Martino J, Ros M, Saltel F. Multitasking discoidin domain receptors are involved in several and specific hallmarks of cancer. Cell Adh Migr 2018; 12:363-377. [PMID: 29701112 DOI: 10.1080/19336918.2018.1465156] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Discoidin domain receptors, DDR1 and DDR2, are two members of collagen receptor family that belong to tyrosine kinase receptor subgroup. Unlike other matrix receptor-like integrins, these collagen receptors have not been extensively studied. However, more and more studies are focusing on their involvement in cancer. These two receptors are present in several subcellular localizations such as intercellular junction or along type I collagen fibers. Consequently, they are involved in multiple cellular functions, for instance, cell cohesion, proliferation, adhesion, migration and invasion. Furthermore, various signaling pathways are associated with these multiple functions. In this review, we highlight and characterize hallmarks of cancer in which DDRs play crucial roles. We discuss recent data from studies that demonstrate the involvement of DDRs in tumor proliferation, cancer mutations, drug resistance, inflammation, neo-angiogenesis and metastasis. DDRs could be potential targets in cancer and we conclude this review by discussing the different ways to inhibits them.
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Affiliation(s)
- Elodie Henriet
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France
| | - Margaux Sala
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France
| | - Aya Abou Hammoud
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France
| | - Adjanie Tuariihionoa
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France
| | - Julie Di Martino
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France
| | - Manon Ros
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France.,c Institute of Molecular and Cell Biology , 61 Biopolis Drive, Proteos, Singapore
| | - Frédéric Saltel
- a INSERM, UMR1053, BaRITOn Bordeaux Research in Translational Oncology , Bordeaux , France.,b Université de Bordeaux , Bordeaux , France
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49
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Qin HY, Zhao WX, Zhao W, Zhang C, Feng XQ, Liu SP, Wang KG. Parametric investigations on the saturation intensity of Coumarin 102 for stimulated emission depletion application. J Microsc 2018; 271:136-144. [PMID: 29683482 DOI: 10.1111/jmi.12703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 03/15/2018] [Accepted: 03/21/2018] [Indexed: 11/29/2022]
Abstract
Stimulated emission depletion (STED) microscopy performed using continuous-wave (CW) lasers has been investigated and developed by Willig et al. (Nature Methods, 2007, 4(11):915) for nearly a decade. Kuang et al. (Review of Scientific Instruments, 2010, 81:053709) developed the CW STED microscopy technique with 405 nm excitation and 532 nm depletion beams. In their research, Coumarin 102 dye was adopted and was found to be depletable. In this study, a parametric investigation of the depletion of Coumarin 102 dye is carried out experimentally. The influence of the excitation and depletion beam intensities and dye concentrations on the depletion efficiency are studied in detail. The results indicate the following: (1) The highest depletion occurs for the 100 μM Coumarin 102 solution, with a 1.4 μW excitation beam and a 115.3 mW depletion beam. (2) The minimum saturation intensity (Is) of STED, that is 13 MW cm-2 , is observed when the Coumarin 102 solution concentration is 10 μM. (3) Is values calculated directly from the depletion power derived with the cross-sectional area due to the full-width-at-half-maximum (FWHM) of the depletion beam show poor accuracy, where Is may be overestimated. Thus, a correction factor for the cross-sectional area is proposed. We also find that Is is not exactly constant for a fixed excitation beam power and dye concentration. This trend indicates that the conventional suppression function η(x)=e- ln (2)ISTED(x)/Is derived from picosecond STED may cause errors in evaluating the depletion process in CW STED microscopy.
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Affiliation(s)
- H-Y Qin
- State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Laboratory of Optoelectronic Technology of Shaanxi Province, National Center for International Research of Photoelectric Technology & Nano-functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, China
| | - W-X Zhao
- State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Laboratory of Optoelectronic Technology of Shaanxi Province, National Center for International Research of Photoelectric Technology & Nano-functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, China
| | - W Zhao
- State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Laboratory of Optoelectronic Technology of Shaanxi Province, National Center for International Research of Photoelectric Technology & Nano-functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, China
| | - C Zhang
- State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Laboratory of Optoelectronic Technology of Shaanxi Province, National Center for International Research of Photoelectric Technology & Nano-functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, China
| | - X-Q Feng
- State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Laboratory of Optoelectronic Technology of Shaanxi Province, National Center for International Research of Photoelectric Technology & Nano-functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, China
| | - S-P Liu
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Suzhou, China
| | - K-G Wang
- State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials, Laboratory of Optoelectronic Technology of Shaanxi Province, National Center for International Research of Photoelectric Technology & Nano-functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, China
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50
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Baranov MV, Revelo NH, Dingjan I, Maraspini R, Ter Beest M, Honigmann A, van den Bogaart G. SWAP70 Organizes the Actin Cytoskeleton and Is Essential for Phagocytosis. Cell Rep 2017; 17:1518-1531. [PMID: 27806292 PMCID: PMC5149533 DOI: 10.1016/j.celrep.2016.10.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 09/05/2016] [Accepted: 10/06/2016] [Indexed: 10/25/2022] Open
Abstract
Actin plays a critical role during the early stages of pathogenic microbe internalization by immune cells. In this study, we identified a key mechanism of actin filament tethering and stabilization to the surface of phagosomes in human dendritic cells. We found that the actin-binding protein SWAP70 is specifically recruited to nascent phagosomes by binding to the lipid phosphatidylinositol (3,4)-bisphosphate. Multi-color super-resolution stimulated emission depletion (STED) microscopy revealed that the actin cage surrounding early phagosomes is formed by multiple concentric rings containing SWAP70. SWAP70 colocalized with and stimulated activation of RAC1, a known activator of actin polymerization, on phagosomes. Genetic ablation of SWAP70 impaired actin polymerization around phagosomes and resulted in a phagocytic defect. These data show a key role for SWAP70 as a scaffold for tethering the peripheral actin cage to phagosomes.
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Affiliation(s)
- Maksim V Baranov
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Natalia H Revelo
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Ilse Dingjan
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Riccardo Maraspini
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands
| | - Alf Honigmann
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 28, 6525GA Nijmegen, the Netherlands.
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