1
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Engl W, Kunstar-Thomas A, Chen S, Ng WS, Sielaff H, Zhao ZW. Single-molecule imaging of SWI/SNF chromatin remodelers reveals bromodomain-mediated and cancer-mutants-specific landscape of multi-modal DNA-binding dynamics. Nat Commun 2024; 15:7646. [PMID: 39223123 PMCID: PMC11369179 DOI: 10.1038/s41467-024-52040-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 08/22/2024] [Indexed: 09/04/2024] Open
Abstract
Despite their prevalent cancer implications, the in vivo dynamics of SWI/SNF chromatin remodelers and how misregulation of such dynamics underpins cancer remain poorly understood. Using live-cell single-molecule tracking, we quantify the intranuclear diffusion and chromatin-binding of three key subunits common to all major human SWI/SNF remodeler complexes (BAF57, BAF155 and BRG1), and resolve two temporally distinct stable binding modes for the fully assembled complex. Super-resolved density mapping reveals heterogeneous, nanoscale remodeler binding "hotspots" across the nucleoplasm where multiple binding events (especially longer-lived ones) preferentially cluster. Importantly, we uncover distinct roles of the bromodomain in modulating chromatin binding/targeting in a DNA-accessibility-dependent manner, pointing to a model where successive longer-lived binding within "hotspots" leads to sustained productive remodeling. Finally, systematic comparison of six common BRG1 mutants implicated in various cancers unveils alterations in chromatin-binding dynamics unique to each mutant, shedding insight into a multi-modal landscape regulating the spatio-temporal organizational dynamics of SWI/SNF remodelers.
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Affiliation(s)
- Wilfried Engl
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Aliz Kunstar-Thomas
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Siyi Chen
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Woei Shyuan Ng
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Hendrik Sielaff
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Ziqing Winston Zhao
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore.
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore.
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore.
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, 119077, Singapore.
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2
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McFadden MH, Emeritt MB, Xu H, Cui Y, Leterrier C, Zala D, Venance L, Lenkei Z. Actomyosin-mediated inhibition of synaptic vesicle release under CB 1R activation. Transl Psychiatry 2024; 14:335. [PMID: 39168993 PMCID: PMC11339458 DOI: 10.1038/s41398-024-03017-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 04/16/2024] [Accepted: 07/08/2024] [Indexed: 08/23/2024] Open
Abstract
Long-term synaptic plasticity is critical for adaptive function of the brain, but presynaptic mechanisms of functional plasticity remain poorly understood. Here, we show that changes in synaptic efficacy induced by activation of the cannabinoid type-1 receptor (CB1R), one of the most widespread G-protein coupled receptors in the brain, requires contractility of the neuronal actomyosin cytoskeleton. Specifically, using a synaptophysin-pHluorin probe (sypH2), we show that inhibitors of non-muscle myosin II (NMII) ATPase as well as one of its upstream effectors Rho-associated kinase (ROCK) prevent the reduction of synaptic vesicle release induced by CB1R activation. Using 3D STORM super-resolution microscopy, we find that activation of CB1R induces a redistribution of synaptic vesicles within presynaptic boutons in an actomyosin dependent manner, leading to vesicle clustering within the bouton and depletion of synaptic vesicles from the active zone. We further show, using sypH2, that inhibitors of NMII and ROCK specifically restore the release of the readily releasable pool of synaptic vesicles from the inhibition induced by CB1R activation. Finally, using slice electrophysiology, we find that activation of both NMII and ROCK is necessary for the long-term, but not the short-term, form of CB1R induced synaptic plasticity at excitatory cortico-striatal synapses. We thus propose a novel mechanism underlying CB1R-induced plasticity, whereby CB1R activation leads to a contraction of the actomyosin cytoskeleton inducing a reorganization of the functional presynaptic vesicle pool, preventing vesicle release and inducing long-term depression.
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Affiliation(s)
- Maureen H McFadden
- Institut Pasteur, Université Paris Cité, Synapse and Circuit Dynamics Laboratory, CNRS UMR 3571, Paris, France
- Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, Paris, France
| | - Michel-Boris Emeritt
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université Paris Cité, INSERM U1266, Paris, France
| | - Hao Xu
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Yihui Cui
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | | | - Diana Zala
- Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, Paris, France
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université Paris Cité, INSERM U1266, Paris, France
| | - Laurent Venance
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Zsolt Lenkei
- Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, Paris, France.
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université Paris Cité, INSERM U1266, Paris, France.
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3
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Barnaba C, Broadbent DG, Kaminsky EG, Perez GI, Schmidt JC. AMPK regulates phagophore-to-autophagosome maturation. J Cell Biol 2024; 223:e202309145. [PMID: 38775785 PMCID: PMC11110907 DOI: 10.1083/jcb.202309145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 03/28/2024] [Accepted: 05/04/2024] [Indexed: 05/24/2024] Open
Abstract
Autophagy is an important metabolic pathway that can non-selectively recycle cellular material or lead to targeted degradation of protein aggregates or damaged organelles. Autophagosome formation starts with autophagy factors accumulating on lipid vesicles containing ATG9. These phagophores attach to donor membranes, expand via ATG2-mediated lipid transfer, capture cargo, and mature into autophagosomes, ultimately fusing with lysosomes for their degradation. Autophagy can be activated by nutrient stress, for example, by a reduction in the cellular levels of amino acids. In contrast, how autophagy is regulated by low cellular ATP levels via the AMP-activated protein kinase (AMPK), an important therapeutic target, is less clear. Using live-cell imaging and an automated image analysis pipeline, we systematically dissect how nutrient starvation regulates autophagosome biogenesis. We demonstrate that glucose starvation downregulates autophagosome maturation by AMPK-mediated inhibition of phagophore tethering to donor membrane. Our results clarify AMPKs regulatory role in autophagy and highlight its potential as a therapeutic target to reduce autophagy.
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Affiliation(s)
- Carlo Barnaba
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - David G. Broadbent
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Emily G. Kaminsky
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Gloria I. Perez
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Jens C. Schmidt
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
- Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, East Lansing, MI, USA
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4
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Cloâtre T, Mondin M, Sibarita JB, Levet F, Thoumine O. Protocol for matching protein localization to synapse morphology in primary rat neurons by correlative super-resolution microscopy. STAR Protoc 2024; 5:103160. [PMID: 38943646 PMCID: PMC11261141 DOI: 10.1016/j.xpro.2024.103160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/17/2024] [Accepted: 06/07/2024] [Indexed: 07/01/2024] Open
Abstract
Super-resolution imaging provides unprecedented visualization of sub-cellular structures, but the two main techniques used, single-molecule localization microscopy (SMLM) and stimulated emission depletion (STED), are not easily reconciled. We present a protocol to super-impose nanoscale protein distribution reconstructed with SMLM to sub-cellular morphology obtained in STED. We describe steps for tracking cells on etched coverslips and registering images from two different microscopes with 30-nm accuracy. In this protocol, synaptic proteins are mapped in the dendritic spines of primary neurons. For complete details on the use and execution of this protocol, please refer to Inavalli et al.1.
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Affiliation(s)
- Tiffany Cloâtre
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, 33000 Bordeaux, France
| | - Magali Mondin
- University Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UAR 3420, US 4, 33000 Bordeaux, France
| | - Jean-Baptiste Sibarita
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, 33000 Bordeaux, France
| | - Florian Levet
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, 33000 Bordeaux, France; University Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UAR 3420, US 4, 33000 Bordeaux, France.
| | - Olivier Thoumine
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, 33000 Bordeaux, France.
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5
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Zhou Q, Glück C, Tang L, Glandorf L, Droux J, El Amki M, Wegener S, Weber B, Razansky D, Chen Z. Cortex-wide transcranial localization microscopy with fluorescently labeled red blood cells. Nat Commun 2024; 15:3526. [PMID: 38664419 PMCID: PMC11045747 DOI: 10.1038/s41467-024-47892-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Large-scale imaging of brain activity with high spatio-temporal resolution is crucial for advancing our understanding of brain function. The existing neuroimaging techniques are largely limited by restricted field of view, slow imaging speed, or otherwise do not have the adequate spatial resolution to capture brain activities on a capillary and cellular level. To address these limitations, we introduce fluorescence localization microscopy aided with sparsely-labeled red blood cells for cortex-wide morphological and functional cerebral angiography with 4.9 µm spatial resolution and 1 s temporal resolution. When combined with fluorescence calcium imaging, the proposed method enables extended recordings of stimulus-evoked neuro-vascular changes in the murine brain while providing simultaneous multiparametric readings of intracellular neuronal activity, blood flow velocity/direction/volume, and vessel diameter. Owing to its simplicity and versatility, the proposed approach will become an invaluable tool for deciphering the regulation of cortical microcirculation and neurovascular coupling in health and disease.
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Affiliation(s)
- Quanyu Zhou
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland
| | - Chaim Glück
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Zurich Neuroscience Center, Zurich, Switzerland
| | - Lin Tang
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland
| | - Lukas Glandorf
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland
| | - Jeanne Droux
- Zurich Neuroscience Center, Zurich, Switzerland
- Department of Neurology, University Hospital and University of Zurich, Zurich, Switzerland
| | - Mohamad El Amki
- Zurich Neuroscience Center, Zurich, Switzerland
- Department of Neurology, University Hospital and University of Zurich, Zurich, Switzerland
| | - Susanne Wegener
- Zurich Neuroscience Center, Zurich, Switzerland
- Department of Neurology, University Hospital and University of Zurich, Zurich, Switzerland
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Zurich Neuroscience Center, Zurich, Switzerland
| | - Daniel Razansky
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland.
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland.
- Zurich Neuroscience Center, Zurich, Switzerland.
| | - Zhenyue Chen
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland.
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland.
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6
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Hou G, Yang Z, Zang D, Fernández JJ, Zhang F, Han R. MarkerDetector: A method for robust fiducial marker detection in electron micrographs using wavelet-based template. J Struct Biol 2024; 216:108044. [PMID: 37967798 DOI: 10.1016/j.jsb.2023.108044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/19/2023] [Accepted: 11/07/2023] [Indexed: 11/17/2023]
Abstract
Fiducial marker detection in electron micrographs becomes an important and challenging task with the development of large-field electron microscopy. The fiducial marker detection plays an important role in several steps during the process of electron micrographs, such as the alignment and parameter calibrations. However, limited by the conditions of low signal-to-noise ratio (SNR) in the electron micrographs, the performance of fiducial marker detection is severely affected. In this work, we propose the MarkerDetector, a novel algorithm for detecting fiducial markers in electron micrographs. The proposed MarkerDetector is built upon the following contributions: Firstly, a wavelet-based template generation algorithm is devised in MarkerDetector. By adopting a shape-based criterion, a high-quality template can be obtained. Secondly, a robust marker determination strategy is devised by utilizing statistic-based filtering, which can guarantee the correctness of the detected fiducial markers. The average running time of our algorithm is 1.67 seconds with promising accuracy, indicating its practical feasibility for applications in electron micrographs.
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Affiliation(s)
- Gaoxin Hou
- Research Center for Mathematics and Interdisciplinary Sciences, Frontiers Science Center for Nonlinear Expectations (Ministry of Education), Shandong University, Qingdao 266237, China
| | - Zhidong Yang
- High Performance Computer Research Center, Institute of Computing Technology, CAS, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dawei Zang
- High Performance Computer Research Center, Institute of Computing Technology, CAS, Beijing 100190, China
| | - Jose-Jesus Fernández
- Spanish National Research Council (CINN-CSIC), Health Research Institute of Asturias (ISPA), Av. Hospital Universitario s/n, Oviedo 33011, Spain
| | - Fa Zhang
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China.
| | - Renmin Han
- Research Center for Mathematics and Interdisciplinary Sciences, Frontiers Science Center for Nonlinear Expectations (Ministry of Education), Shandong University, Qingdao 266237, China; King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, Thuwal 23955, Saudi Arabia.
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7
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Hanson A, Reme R, Telerman N, Yamamoto W, Olivo-Marin JC, Lagache T, Yuste R. Automatic monitoring of neural activity with single-cell resolution in behaving Hydra. Sci Rep 2024; 14:5083. [PMID: 38429381 PMCID: PMC10907378 DOI: 10.1038/s41598-024-55608-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/26/2024] [Indexed: 03/03/2024] Open
Abstract
The ability to record every spike from every neuron in a behaving animal is one of the holy grails of neuroscience. Here, we report coming one step closer towards this goal with the development of an end-to-end pipeline that automatically tracks and extracts calcium signals from individual neurons in the cnidarian Hydra vulgaris. We imaged dually labeled (nuclear tdTomato and cytoplasmic GCaMP7s) transgenic Hydra and developed an open-source Python platform (TraSE-IN) for the Tracking and Spike Estimation of Individual Neurons in the animal during behavior. The TraSE-IN platform comprises a series of modules that segments and tracks each nucleus over time and extracts the corresponding calcium activity in the GCaMP channel. Another series of signal processing modules allows robust prediction of individual spikes from each neuron's calcium signal. This complete pipeline will facilitate the automatic generation and analysis of large-scale datasets of single-cell resolution neural activity in Hydra, and potentially other model organisms, paving the way towards deciphering the neural code of an entire animal.
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Affiliation(s)
- Alison Hanson
- Department of Biological Sciences, Neurotechnology Center, Columbia University, New York, NY, USA.
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University, New York, NY, USA.
| | - Raphael Reme
- UMR3691, BioImage Analysis Unit, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
| | - Noah Telerman
- Department of Biological Sciences, Neurotechnology Center, Columbia University, New York, NY, USA
| | - Wataru Yamamoto
- Department of Biological Sciences, Neurotechnology Center, Columbia University, New York, NY, USA
| | | | - Thibault Lagache
- UMR3691, BioImage Analysis Unit, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
| | - Rafael Yuste
- Department of Biological Sciences, Neurotechnology Center, Columbia University, New York, NY, USA
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8
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Bénac N, Ezequiel Saraceno G, Butler C, Kuga N, Nishimura Y, Yokoi T, Su P, Sasaki T, Petit-Pedrol M, Galland R, Studer V, Liu F, Ikegaya Y, Sibarita JB, Groc L. Non-canonical interplay between glutamatergic NMDA and dopamine receptors shapes synaptogenesis. Nat Commun 2024; 15:27. [PMID: 38167277 PMCID: PMC10762086 DOI: 10.1038/s41467-023-44301-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 12/07/2023] [Indexed: 01/05/2024] Open
Abstract
Direct interactions between receptors at the neuronal surface have long been proposed to tune signaling cascades and neuronal communication in health and disease. Yet, the lack of direct investigation methods to measure, in live neurons, the interaction between different membrane receptors at the single molecule level has raised unanswered questions on the biophysical properties and biological roles of such receptor interactome. Using a multidimensional spectral single molecule-localization microscopy (MS-SMLM) approach, we monitored the interaction between two membrane receptors, i.e. glutamatergic NMDA (NMDAR) and G protein-coupled dopamine D1 (D1R) receptors. The transient interaction was randomly observed along the dendritic tree of hippocampal neurons. It was higher early in development, promoting the formation of NMDAR-D1R complexes in an mGluR5- and CK1-dependent manner, favoring NMDAR clusters and synaptogenesis in a dopamine receptor signaling-independent manner. Preventing the interaction in the neonate, and not adult, brain alters in vivo spontaneous neuronal network activity pattern in male mice. Thus, a weak and transient interaction between NMDAR and D1R plays a structural and functional role in the developing brain.
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Affiliation(s)
- Nathan Bénac
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | | | - Corey Butler
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Nahoko Kuga
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-aoba, Sendai, Miyagi, 980-8578, Japan
| | - Yuya Nishimura
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Taiki Yokoi
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-aoba, Sendai, Miyagi, 980-8578, Japan
| | - Ping Su
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Canada
| | - Takuya Sasaki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-aoba, Sendai, Miyagi, 980-8578, Japan
| | | | - Rémi Galland
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Vincent Studer
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Fang Liu
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Canada
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-0033, Japan
- Center for Information and Neural Networks, Suita City, Osaka, 565-0871, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, 113-0033, Japan
| | | | - Laurent Groc
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France.
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9
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Longfield SF, Mollazade M, Wallis TP, Gormal RS, Joensuu M, Wark JR, van Waardenberg AJ, Small C, Graham ME, Meunier FA, Martínez-Mármol R. Tau forms synaptic nano-biomolecular condensates controlling the dynamic clustering of recycling synaptic vesicles. Nat Commun 2023; 14:7277. [PMID: 37949856 PMCID: PMC10638352 DOI: 10.1038/s41467-023-43130-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
Neuronal communication relies on the release of neurotransmitters from various populations of synaptic vesicles. Despite displaying vastly different release probabilities and mobilities, the reserve and recycling pool of vesicles co-exist within a single cluster suggesting that small synaptic biomolecular condensates could regulate their nanoscale distribution. Here, we performed a large-scale activity-dependent phosphoproteome analysis of hippocampal neurons in vitro and identified Tau as a highly phosphorylated and disordered candidate protein. Single-molecule super-resolution microscopy revealed that Tau undergoes liquid-liquid phase separation to generate presynaptic nanoclusters whose density and number are regulated by activity. This activity-dependent diffusion process allows Tau to translocate into the presynapse where it forms biomolecular condensates, to selectively control the mobility of recycling vesicles. Tau, therefore, forms presynaptic nano-biomolecular condensates that regulate the nanoscale organization of synaptic vesicles in an activity-dependent manner.
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Affiliation(s)
- Shanley F Longfield
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Mahdie Mollazade
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Jesse R Wark
- Synapse Proteomics, Children's Medical Research Institute (CMRI), The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | | | - Christopher Small
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Mark E Graham
- Synapse Proteomics, Children's Medical Research Institute (CMRI), The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
- School of Biomedical Science, The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
| | - Ramón Martínez-Mármol
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland; St Lucia Campus, Brisbane, QLD, 4072, Australia.
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10
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Barnaba C, Broadbent DG, Perez GI, Schmidt JC. AMPK Regulates Phagophore-to-Autophagosome Maturation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.559981. [PMID: 37808644 PMCID: PMC10557706 DOI: 10.1101/2023.09.28.559981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Autophagy is an important metabolic pathway that can non-selectively recycle cellular material or lead to targeted degradation of protein aggregates or damaged organelles. Autophagosome formation starts with autophagy factors accumulating on lipid vesicles containing ATG9. These phagophores attach to donor membranes, expand via ATG2-mediated lipid transfer, capture cargo, and mature into autophagosomes, ultimately fusing with lysosomes for their degradation. Autophagy can be activated by nutrient stress, for example by a reduction in the cellular levels of amino acids. In contrast, how autophagy is regulated by low cellular ATP levels via the AMP-activated protein kinase (AMPK), an important therapeutic target, is less clear. Using live-cell imaging and an automated image analysis pipeline, we systematically dissect how nutrient starvation regulates autophagosome biogenesis. We demonstrate that glucose starvation downregulates autophagosome maturation by AMPK mediated inhibition of phagophores tethering to donor membranes. Our results clarify AMPK's regulatory role in autophagy and highlight its potential as a therapeutic target to reduce autophagy.
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Affiliation(s)
- Carlo Barnaba
- Institute for Quantitative Health Science and Engineering
| | - David G. Broadbent
- Institute for Quantitative Health Science and Engineering
- College of Osteopathic Medicine
- Department of Physiology
| | | | - Jens C. Schmidt
- Institute for Quantitative Health Science and Engineering
- Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, East Lansing, USA
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11
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Friedl K, Mau A, Boroni-Rueda F, Caorsi V, Bourg N, Lévêque-Fort S, Leterrier C. Assessing crosstalk in simultaneous multicolor single-molecule localization microscopy. CELL REPORTS METHODS 2023; 3:100571. [PMID: 37751691 PMCID: PMC10545913 DOI: 10.1016/j.crmeth.2023.100571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 07/03/2023] [Accepted: 08/04/2023] [Indexed: 09/28/2023]
Abstract
Single-molecule localization microscopy (SMLM) can reach sub-50 nm resolution using techniques such as stochastic optical reconstruction microscopy (STORM) or DNA-point accumulation for imaging in nanoscale topography (PAINT). Here we implement two approaches for faster multicolor SMLM by splitting the emitted fluorescence toward two cameras: simultaneous two-color DNA-PAINT (S2C-DNA-PAINT) that images spectrally separated red and far-red imager strands on each camera, and spectral demixing dSTORM (SD-dSTORM) where spectrally close far-red fluorophores appear on both cameras before being identified by demixing. Using S2C-DNA-PAINT as a reference for low crosstalk, we evaluate SD-dSTORM crosstalk using three types of samples: DNA origami nanorulers of different sizes, single-target labeled cells, or cells labeled for multiple targets. We then assess if crosstalk can affect the detection of biologically relevant subdiffraction patterns. Extending these approaches to three-dimensional acquisition and SD-dSTORM to three-color imaging, we show that spectral demixing is an attractive option for robust and versatile multicolor SMLM investigations.
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Affiliation(s)
- Karoline Friedl
- Aix Marseille Université, CNRS, INP UMR7051, NeuroCyto, 13005 Marseille, France; Abbelight, 191 Avenue Aristide Briand, 94230 Cachan, France
| | - Adrien Mau
- Abbelight, 191 Avenue Aristide Briand, 94230 Cachan, France; Université Paris Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Fanny Boroni-Rueda
- Aix Marseille Université, CNRS, INP UMR7051, NeuroCyto, 13005 Marseille, France
| | | | - Nicolas Bourg
- Abbelight, 191 Avenue Aristide Briand, 94230 Cachan, France
| | - Sandrine Lévêque-Fort
- Université Paris Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Christophe Leterrier
- Aix Marseille Université, CNRS, INP UMR7051, NeuroCyto, 13005 Marseille, France.
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12
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Hanson A, Reme R, Telerman N, Yamamoto W, Olivo-Marin JC, Lagache T, Yuste R. Automatic monitoring of whole-body neural activity in behaving Hydra. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.22.559063. [PMID: 37790332 PMCID: PMC10542483 DOI: 10.1101/2023.09.22.559063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The ability to record every spike from every neuron in a behaving animal is one of the holy grails of neuroscience. Here, we report coming one step closer towards this goal with the development of an end-to-end pipeline that automatically tracks and extracts calcium signals from individual neurons in the cnidarian Hydra vulgaris. We imaged dually labeled (nuclear tdTomato and cytoplasmic GCaMP7s) transgenic Hydra and developed an open-source Python platform (TraSE-IN) for the Tracking and Spike Estimation of Individual Neurons in the animal during behavior. The TraSE-IN platform comprises a series of modules that segments and tracks each nucleus over time and extracts the corresponding calcium activity in the GCaMP channel. Another series of signal processing modules allows robust prediction of individual spikes from each neuron's calcium signal. This complete pipeline will facilitate the automatic generation and analysis of large-scale datasets of single-cell resolution neural activity in Hydra, and potentially other model organisms, paving the way towards deciphering the neural code of an entire animal.
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Affiliation(s)
- Alison Hanson
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University, New York, NY, USA
| | - Raphael Reme
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, BioImage Analysis Unit, Paris, France
| | - Noah Telerman
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Wataru Yamamoto
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA
| | | | - Thibault Lagache
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, BioImage Analysis Unit, Paris, France
| | - Rafael Yuste
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA
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13
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Nava G, Casiraghi L, Carzaniga T, Zanchetta G, Chiari M, Damin F, Bollati V, Signorini L, Delbue S, Bellini T, Buscaglia M. Digital Detection of Single Virus Particles by Multi-Spot, Label-Free Imaging Biosensor on Anti-Reflective Glass. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300947. [PMID: 37060208 DOI: 10.1002/smll.202300947] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/21/2023] [Indexed: 06/19/2023]
Abstract
Rapid detection of whole virus particles in biological or environmental samples represents an unmet need for the containment of infectious diseases. Here, an optical device enabling the enumeration of single virion particles binding on antibody or aptamers immobilized on a surface with anti-reflective coating is described. In this regime, nanoparticles adhering to the sensor surface provide localized contributions to the reflected field that become detectable because of their mixing with the interfering waves in the reflection direction. Thus, these settings are exploited to realize a scan-free, label-free, micro-array-type digital assay on a disposable cartridge, in which the virion counting takes place in wide field-of-view imaging. With this approach we could quantify, by enumeration, different variants of SARS-CoV-2 virions interacting with antibodies and aptamers immobilized on different spots. For all tested variants, the aptamers showed larger affinity but lower specificity relative to the antibodies. It is found that the combination of different probes on the same surface enables increasing specificity of detection and dynamic range.
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Affiliation(s)
- Giovanni Nava
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universitá degli Studi di Milano, via F.lli Cervi, 93, Segrate, Milano, 20054, Italy
| | - Luca Casiraghi
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universitá degli Studi di Milano, via F.lli Cervi, 93, Segrate, Milano, 20054, Italy
| | - Thomas Carzaniga
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universitá degli Studi di Milano, via F.lli Cervi, 93, Segrate, Milano, 20054, Italy
| | - Giuliano Zanchetta
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universitá degli Studi di Milano, via F.lli Cervi, 93, Segrate, Milano, 20054, Italy
| | - Marcella Chiari
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", National Research Council of Italy (SCITEC-CNR), via Mario Bianco 11, Milano, 20131, Italy
| | - Francesco Damin
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", National Research Council of Italy (SCITEC-CNR), via Mario Bianco 11, Milano, 20131, Italy
| | - Valentina Bollati
- Dipartimento di Scienze Cliniche e di Comunitá, Universitá degli Studi di Milano, via S. Barnaba 8, Milano, 20122, Italy
| | - Lucia Signorini
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Universitá degli Studi di Milano, via Pascal 36, Milano, 20133, Italy
| | - Serena Delbue
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Universitá degli Studi di Milano, via Pascal 36, Milano, 20133, Italy
| | - Tommaso Bellini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universitá degli Studi di Milano, via F.lli Cervi, 93, Segrate, Milano, 20054, Italy
| | - Marco Buscaglia
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universitá degli Studi di Milano, via F.lli Cervi, 93, Segrate, Milano, 20054, Italy
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14
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Joensuu M, Syed P, Saber SH, Lanoue V, Wallis TP, Rae J, Blum A, Gormal RS, Small C, Sanders S, Jiang A, Mahrhold S, Krez N, Cousin MA, Cooper‐White R, Cooper‐White JJ, Collins BM, Parton RG, Balistreri G, Rummel A, Meunier FA. Presynaptic targeting of botulinum neurotoxin type A requires a tripartite PSG-Syt1-SV2 plasma membrane nanocluster for synaptic vesicle entry. EMBO J 2023; 42:e112095. [PMID: 37226896 PMCID: PMC10308369 DOI: 10.15252/embj.2022112095] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 04/18/2023] [Accepted: 04/28/2023] [Indexed: 05/26/2023] Open
Abstract
The unique nerve terminal targeting of botulinum neurotoxin type A (BoNT/A) is due to its capacity to bind two receptors on the neuronal plasma membrane: polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Whether and how PSGs and SV2 may coordinate other proteins for BoNT/A recruitment and internalization remains unknown. Here, we demonstrate that the targeted endocytosis of BoNT/A into synaptic vesicles (SVs) requires a tripartite surface nanocluster. Live-cell super-resolution imaging and electron microscopy of catalytically inactivated BoNT/A wildtype and receptor-binding-deficient mutants in cultured hippocampal neurons demonstrated that BoNT/A must bind coincidentally to a PSG and SV2 to target synaptic vesicles. We reveal that BoNT/A simultaneously interacts with a preassembled PSG-synaptotagmin-1 (Syt1) complex and SV2 on the neuronal plasma membrane, facilitating Syt1-SV2 nanoclustering that controls endocytic sorting of the toxin into synaptic vesicles. Syt1 CRISPRi knockdown suppressed BoNT/A- and BoNT/E-induced neurointoxication as quantified by SNAP-25 cleavage, suggesting that this tripartite nanocluster may be a unifying entry point for selected botulinum neurotoxins that hijack this for synaptic vesicle targeting.
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Affiliation(s)
- Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandBrisbaneQLDAustralia
| | - Parnayan Syed
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Saber H Saber
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandBrisbaneQLDAustralia
| | - Vanessa Lanoue
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - James Rae
- Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
| | - Ailisa Blum
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Christopher Small
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Shanley Sanders
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Anmin Jiang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
| | - Stefan Mahrhold
- Institut für ToxikologieMedizinische Hochschule HannoverHannoverGermany
| | - Nadja Krez
- Institut für ToxikologieMedizinische Hochschule HannoverHannoverGermany
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, Hugh Robson BuildingUniversity of EdinburghEdinburghUK
- Muir Maxwell Epilepsy CentreUniversity of EdinburghEdinburghUK
- Simons Initiative for the Developing BrainUniversity of EdinburghEdinburghUK
| | - Ruby Cooper‐White
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandBrisbaneQLDAustralia
- School of Chemical EngineeringThe University of QueenslandBrisbaneQLDAustralia
| | - Justin J Cooper‐White
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandBrisbaneQLDAustralia
- School of Chemical EngineeringThe University of QueenslandBrisbaneQLDAustralia
- UQ Centre for Stem Cell Ageing and Regenerative EngineeringThe University of QueenslandBrisbaneQLDAustralia
| | - Brett M Collins
- Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
| | - Robert G Parton
- Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
- Centre for Microscopy and MicroanalysisThe University of QueenslandBrisbaneQLDAustralia
| | - Giuseppe Balistreri
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Department of Virology, Faculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Andreas Rummel
- Institut für ToxikologieMedizinische Hochschule HannoverHannoverGermany
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneQLDAustralia
- School of Biomedical SciencesThe University of QueenslandBrisbaneQLDAustralia
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15
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Mangalwedhekar R, Singh N, Thakur CS, Seelamantula CS, Jose M, Nair D. Achieving nanoscale precision using neuromorphic localization microscopy. NATURE NANOTECHNOLOGY 2023; 18:380-389. [PMID: 36690737 DOI: 10.1038/s41565-022-01291-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 11/09/2022] [Indexed: 06/17/2023]
Abstract
Neuromorphic cameras are a new class of dynamic-vision-inspired sensors that encode the rate of change of intensity as events. They can asynchronously record intensity changes as spikes, independent of the other pixels in the receptive field, resulting in sparse measurements. This recording of such sparse events makes them ideal for imaging dynamic processes, such as the stochastic emission of isolated single molecules. Here we show the application of neuromorphic detection to localize nanoscale fluorescent objects below the diffraction limit, with a precision below 20 nm. We demonstrate a combination of neuromorphic detection with segmentation and deep learning approaches to localize and track fluorescent particles below 50 nm with millisecond temporal resolution. Furthermore, we show that combining information from events resulting from the rate of change of intensities improves the classical limit of centroid estimation of single fluorescent objects by nearly a factor of two. Additionally, we validate that using post-processed data from the neuromorphic detector at defined windows of temporal integration allows a better evaluation of the fractalized diffusion of single particle trajectories. Our observations and analysis is useful for event sensing by nonlinear neuromorphic devices to ameliorate real-time particle localization approaches at the nanoscale.
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Affiliation(s)
| | - Nivedita Singh
- Centre for Neuroscience, Indian Institute of Science, Bangalore, India
| | - Chetan Singh Thakur
- Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore, India
| | | | - Mini Jose
- Centre for Neuroscience, Indian Institute of Science, Bangalore, India
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore, India.
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16
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Martins CS, Taveneau C, Castro-Linares G, Baibakov M, Buzhinsky N, Eroles M, Milanović V, Omi S, Pedelacq JD, Iv F, Bouillard L, Llewellyn A, Gomes M, Belhabib M, Kuzmić M, Verdier-Pinard P, Lee S, Badache A, Kumar S, Chandre C, Brasselet S, Rico F, Rossier O, Koenderink GH, Wenger J, Cabantous S, Mavrakis M. Human septins organize as octamer-based filaments and mediate actin-membrane anchoring in cells. J Cell Biol 2023; 222:213778. [PMID: 36562751 PMCID: PMC9802686 DOI: 10.1083/jcb.202203016] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 10/20/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Septins are cytoskeletal proteins conserved from algae and protists to mammals. A unique feature of septins is their presence as heteromeric complexes that polymerize into filaments in solution and on lipid membranes. Although animal septins associate extensively with actin-based structures in cells, whether septins organize as filaments in cells and if septin organization impacts septin function is not known. Customizing a tripartite split-GFP complementation assay, we show that all septins decorating actin stress fibers are octamer-containing filaments. Depleting octamers or preventing septins from polymerizing leads to a loss of stress fibers and reduced cell stiffness. Super-resolution microscopy revealed septin fibers with widths compatible with their organization as paired septin filaments. Nanometer-resolved distance measurements and single-protein tracking further showed that septin filaments are membrane bound and largely immobilized. Finally, reconstitution assays showed that septin filaments mediate actin-membrane anchoring. We propose that septin organization as octamer-based filaments is essential for septin function in anchoring and stabilizing actin filaments at the plasma membrane.
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Affiliation(s)
- Carla Silva Martins
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France.,Centre de Recherche en Cancérologie de Toulouse (CRCT), INSERM, Université de Toulouse, UPS, CNRS, Toulouse, France
| | - Cyntia Taveneau
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Gerard Castro-Linares
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Mikhail Baibakov
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Nicolas Buzhinsky
- CNRS, INSERM, LAI, Turing Centre for Living Systems, Aix-Marseille Univ, Marseille, France>
| | - Mar Eroles
- CNRS, INSERM, LAI, Turing Centre for Living Systems, Aix-Marseille Univ, Marseille, France>
| | - Violeta Milanović
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Shizue Omi
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Jean-Denis Pedelacq
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III-Paul Sabatier (UPS), Toulouse, France
| | - Francois Iv
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Léa Bouillard
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Alexander Llewellyn
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Maxime Gomes
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Mayssa Belhabib
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Mira Kuzmić
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, Marseille, France
| | - Pascal Verdier-Pinard
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, Marseille, France
| | - Stacey Lee
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Ali Badache
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM, Institut Paoli-Calmettes, Aix Marseille Univ, CNRS, Marseille, France
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | | | - Sophie Brasselet
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Felix Rico
- CNRS, INSERM, LAI, Turing Centre for Living Systems, Aix-Marseille Univ, Marseille, France>
| | - Olivier Rossier
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Jerome Wenger
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
| | - Stéphanie Cabantous
- Centre de Recherche en Cancérologie de Toulouse (CRCT), INSERM, Université de Toulouse, UPS, CNRS, Toulouse, France
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Marseille, Marseille, France
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17
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Simulation-based inference for non-parametric statistical comparison of biomolecule dynamics. PLoS Comput Biol 2023; 19:e1010088. [PMID: 36730436 PMCID: PMC9928078 DOI: 10.1371/journal.pcbi.1010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 02/14/2023] [Accepted: 01/16/2023] [Indexed: 02/04/2023] Open
Abstract
Numerous models have been developed to account for the complex properties of the random walks of biomolecules. However, when analysing experimental data, conditions are rarely met to ensure model identification. The dynamics may simultaneously be influenced by spatial and temporal heterogeneities of the environment, out-of-equilibrium fluxes and conformal changes of the tracked molecules. Recorded trajectories are often too short to reliably discern such multi-scale dynamics, which precludes unambiguous assessment of the type of random walk and its parameters. Furthermore, the motion of biomolecules may not be well described by a single, canonical random walk model. Here, we develop a two-step statistical testing scheme for comparing biomolecule dynamics observed in different experimental conditions without having to identify or make strong prior assumptions about the model generating the recorded random walks. We first train a graph neural network to perform simulation-based inference and thus learn a rich summary statistics vector describing individual trajectories. We then compare trajectories obtained in different biological conditions using a non-parametric maximum mean discrepancy (MMD) statistical test on their so-obtained summary statistics. This procedure allows us to characterise sets of random walks regardless of their generating models, without resorting to model-specific physical quantities or estimators. We first validate the relevance of our approach on numerically simulated trajectories. This demonstrates both the statistical power of the MMD test and the descriptive power of the learnt summary statistics compared to estimates of physical quantities. We then illustrate the ability of our framework to detect changes in α-synuclein dynamics at synapses in cultured cortical neurons, in response to membrane depolarisation, and show that detected differences are largely driven by increased protein mobility in the depolarised state, in agreement with previous findings. The method provides a means of interpreting the differences it detects in terms of single trajectory characteristics. Finally, we emphasise the interest of performing various comparisons to probe the heterogeneity of experimentally acquired datasets at different levels of granularity (e.g., biological replicates, fields of view, and organelles).
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18
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Fyn nanoclustering requires switching to an open conformation and is enhanced by FTLD-Tau biomolecular condensates. Mol Psychiatry 2023; 28:946-962. [PMID: 36258016 PMCID: PMC9908554 DOI: 10.1038/s41380-022-01825-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/19/2022] [Accepted: 09/27/2022] [Indexed: 11/08/2022]
Abstract
Fyn is a Src kinase that controls critical signalling cascades and has been implicated in learning and memory. Postsynaptic enrichment of Fyn underpins synaptotoxicity in dementias such as Alzheimer's disease and frontotemporal lobar degeneration with Tau pathology (FTLD-Tau). The FLTD P301L mutant Tau is associated with a higher propensity to undergo liquid-liquid phase separation (LLPS) and form biomolecular condensates. Expression of P301L mutant Tau promotes aberrant trapping of Fyn in nanoclusters within hippocampal dendrites by an unknown mechanism. Here, we used single-particle tracking photoactivated localisation microscopy to demonstrate that the opening of Fyn into its primed conformation promotes its nanoclustering in dendrites leading to increased Fyn/ERK/S6 downstream signalling. Preventing the auto-inhibitory closed conformation of Fyn through phospho-inhibition or through perturbation of its SH3 domain increased Fyn's nanoscale trapping, whereas inhibition of the catalytic domain had no impact. By combining pharmacological and genetic approaches, we demonstrate that P301L Tau enhanced both Fyn nanoclustering and Fyn/ERK/S6 signalling via its ability to form biomolecular condensates. Together, our findings demonstrate that Fyn alternates between a closed and an open conformation, the latter being enzymatically active and clustered. Furthermore, pathogenic immobilisation of Fyn relies on the ability of P301L Tau to form biomolecular condensates, thus highlighting the critical importance of LLPS in controlling nanoclustering and downstream intracellular signalling events.
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19
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Padmanabhan P, Kneynsberg A, Cruz E, Amor R, Sibarita JB, Götz J. Single-molecule imaging reveals Tau trapping at nanometer-sized dynamic hot spots near the plasma membrane that persists after microtubule perturbation and cholesterol depletion. EMBO J 2022; 41:e111265. [PMID: 36004506 PMCID: PMC9531302 DOI: 10.15252/embj.2022111265] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 11/25/2022] Open
Abstract
Accumulation of aggregates of the microtubule‐binding protein Tau is a pathological hallmark of Alzheimer's disease. While Tau is thought to primarily associate with microtubules, it also interacts with and localizes to the plasma membrane. However, little is known about how Tau behaves and organizes at the plasma membrane of live cells. Using quantitative, single‐molecule imaging, we show that Tau exhibits spatial and kinetic heterogeneity near the plasma membrane of live cells, resulting in the formation of nanometer‐sized hot spots. The hot spots lasted tens of seconds, much longer than the short dwell time (∼ 40 ms) of Tau on microtubules. Pharmacological and biochemical disruption of Tau/microtubule interactions did not prevent hot spot formation, suggesting that these are different from the reported Tau condensation on microtubules. Although cholesterol removal has been shown to reduce Tau pathology, its acute depletion did not affect Tau hot spot dynamics. Our study identifies an intrinsic dynamic property of Tau near the plasma membrane that may facilitate the formation of assembly sites for Tau to assume its physiological and pathological functions.
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Affiliation(s)
- Pranesh Padmanabhan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Andrew Kneynsberg
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Esteban Cruz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Rumelo Amor
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Jean-Baptiste Sibarita
- Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR, Bordeaux, France
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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20
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Shaw TR, Fazekas FJ, Kim S, Flanagan-Natoli JC, Sumrall ER, Veatch SL. Estimating the localization spread function of static single-molecule localization microscopy images. Biophys J 2022; 121:2906-2920. [PMID: 35787472 PMCID: PMC9388596 DOI: 10.1016/j.bpj.2022.06.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/17/2022] [Accepted: 06/29/2022] [Indexed: 11/27/2022] Open
Abstract
Single-molecule localization microscopy (SMLM) permits the visualization of cellular structures an order of magnitude smaller than the diffraction limit of visible light, and an accurate, objective evaluation of the resolution of an SMLM data set is an essential aspect of the image processing and analysis pipeline. Here, we present a simple method to estimate the localization spread function (LSF) of a static SMLM data set directly from acquired localizations, exploiting the correlated dynamics of individual emitters and properties of the pair autocorrelation function evaluated in both time and space. The method is demonstrated on simulated localizations, DNA origami rulers, and cellular structures labeled by dye-conjugated antibodies, DNA-PAINT, or fluorescent fusion proteins. We show that experimentally obtained images have LSFs that are broader than expected from the localization precision alone, due to additional uncertainty accrued when localizing molecules imaged over time.
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Affiliation(s)
- Thomas R Shaw
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan; Program in Applied Physics, University of Michigan, Ann Arbor, Michigan
| | - Frank J Fazekas
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Sumin Kim
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan
| | | | - Emily R Sumrall
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Sarah L Veatch
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan; Program in Applied Physics, University of Michigan, Ann Arbor, Michigan.
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21
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Imaging Minimal Bacteria at the Nanoscale: a Reliable and Versatile Process to Perform Single-Molecule Localization Microscopy in Mycoplasmas. Microbiol Spectr 2022; 10:e0064522. [PMID: 35638916 PMCID: PMC9241803 DOI: 10.1128/spectrum.00645-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mycoplasmas are the smallest free-living organisms. These bacteria are important models for both fundamental and synthetic biology, owing to their highly reduced genomes. They are also relevant in the medical and veterinary fields, as they are pathogenic to both humans and most livestock species. Mycoplasma cells have minute sizes, often in the 300- to 800-nm range. As these dimensions are close to the diffraction limit of visible light, fluorescence imaging in mycoplasmas is often poorly informative. Recently developed superresolution imaging techniques can break this diffraction limit, improving the imaging resolution by an order of magnitude and offering a new nanoscale vision of the organization of these bacteria. These techniques have, however, not been applied to mycoplasmas before. Here, we describe an efficient and reliable protocol to perform single-molecule localization microscopy (SMLM) imaging in mycoplasmas. We provide a polyvalent transposon-based system to express the photoconvertible fluorescent protein mEos3.2, enabling photo-activated localization microscopy (PALM) in most Mycoplasma species. We also describe the application of direct stochastic optical reconstruction microscopy (dSTORM). We showcase the potential of these techniques by studying the subcellular localization of two proteins of interest. Our work highlights the benefits of state-of-the-art microscopy techniques for mycoplasmology and provides an incentive to further the development of SMLM strategies to study these organisms in the future. IMPORTANCE Mycoplasmas are important models in biology, as well as highly problematic pathogens in the medical and veterinary fields. The very small sizes of these bacteria, well below a micron, limits the usefulness of traditional fluorescence imaging methods, as their resolution limit is similar to the dimensions of the cells. Here, to bypass this issue, we established a set of state-of-the-art superresolution microscopy techniques in a wide range of Mycoplasma species. We describe two strategies: PALM, based on the expression of a specific photoconvertible fluorescent protein, and dSTORM, based on fluorophore-coupled antibody labeling. With these methods, we successfully performed single-molecule imaging of proteins of interest at the surface of the cells and in the cytoplasm, at lateral resolutions well below 50 nm. Our work paves the way toward a better understanding of mycoplasma biology through imaging of subcellular structures at the nanometer scale.
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22
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Toledo A, Letellier M, Bimbi G, Tessier B, Daburon S, Favereaux A, Chamma I, Vennekens K, Vanderlinden J, Sainlos M, de Wit J, Choquet D, Thoumine O. MDGAs are fast-diffusing molecules that delay excitatory synapse development by altering neuroligin behavior. eLife 2022; 11:75233. [PMID: 35532105 PMCID: PMC9084894 DOI: 10.7554/elife.75233] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/11/2022] [Indexed: 12/28/2022] Open
Abstract
MDGA molecules can bind neuroligins and interfere with trans-synaptic interactions to neurexins, thereby impairing synapse development. However, the subcellular localization and dynamics of MDGAs, or their specific action mode in neurons remain unclear. Here, surface immunostaining of endogenous MDGAs and single molecule tracking of recombinant MDGAs in dissociated hippocampal neurons reveal that MDGAs are homogeneously distributed and exhibit fast membrane diffusion, with a small reduction in mobility across neuronal maturation. Knocking-down/out MDGAs using shRNAs and CRISPR/Cas9 strategies increases the density of excitatory synapses, the membrane confinement of neuroligin-1, and the phosphotyrosine level of neuroligins associated with excitatory post-synaptic differentiation. Finally, MDGA silencing reduces the mobility of AMPA receptors, increases the frequency of miniature EPSCs (but not IPSCs), and selectively enhances evoked AMPA-receptor-mediated EPSCs in CA1 pyramidal neurons. Overall, our results support a mechanism by which interactions between MDGAs and neuroligin-1 delays the assembly of functional excitatory synapses containing AMPA receptors.
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Affiliation(s)
- Andrea Toledo
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Mathieu Letellier
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Giorgia Bimbi
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Béatrice Tessier
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Sophie Daburon
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Alexandre Favereaux
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Ingrid Chamma
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Kristel Vennekens
- VIB Center for Brain & Disease Research and KU Leuven, Department of Neurosciences, Leuven Brain Institute
| | - Jeroen Vanderlinden
- VIB Center for Brain & Disease Research and KU Leuven, Department of Neurosciences, Leuven Brain Institute
| | - Matthieu Sainlos
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Joris de Wit
- VIB Center for Brain & Disease Research and KU Leuven, Department of Neurosciences, Leuven Brain Institute
| | - Daniel Choquet
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
- University of Bordeaux, CNRS UAR 3420, INSERM, Bordeaux Imaging Center
| | - Olivier Thoumine
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
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23
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Lagardère M, Drouet A, Sainlos M, Thoumine O. High-Resolution Fluorescence Imaging Combined With Computer Simulations to Quantitate Surface Dynamics and Nanoscale Organization of Neuroligin-1 at Synapses. Front Synaptic Neurosci 2022; 14:835427. [PMID: 35546899 PMCID: PMC9083120 DOI: 10.3389/fnsyn.2022.835427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/09/2022] [Indexed: 11/13/2022] Open
Abstract
Neuroligins (NLGNs) form a family of cell adhesion molecules implicated in synapse development, but the mechanisms that retain these proteins at synapses are still incompletely understood. Recent studies indicate that surface-associated NLGN1 is diffusionally trapped at synapses, where it interacts with quasi-static scaffolding elements of the post-synaptic density. Whereas single molecule tracking reveals rapid diffusion and transient immobilization of NLGN1 at synapses within seconds, fluorescence recovery after photobleaching experiments indicate instead a long-term turnover of NLGN1 at synapse, in the hour time range. To gain insight into the mechanisms supporting NLGN1 anchorage at post-synapses and try to reconcile those experimental paradigms, we quantitatively analyzed here live-cell and super-resolution imaging experiments performed on NLGN1 using a newly released simulator of membrane protein dynamics for fluorescence microscopy, FluoSim. Based on a small set of parameters including diffusion coefficients, binding constants, and photophysical rates, the framework describes fairly well the dynamic behavior of extra-synaptic and synaptic NLGN1 over both short and long time ranges, and provides an estimate of NLGN1 copy numbers in post-synaptic densities at steady-state (around 50 dimers). One striking result is that the residence time of NLGN1 at synapses is much longer than what can be expected from extracellular interactions with pre-synaptic neurexins only, suggesting that NLGN1 is stabilized at synapses through multivalent interactions with intracellular post-synaptic scaffolding proteins.
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24
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Butler C, Saraceno GE, Kechkar A, Bénac N, Studer V, Dupuis JP, Groc L, Galland R, Sibarita JB. Multi-Dimensional Spectral Single Molecule Localization Microscopy. FRONTIERS IN BIOINFORMATICS 2022; 2:813494. [PMID: 36304321 PMCID: PMC9580959 DOI: 10.3389/fbinf.2022.813494] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/12/2022] [Indexed: 11/13/2022] Open
Abstract
Single molecule localization (SML) and tracking (SPT) techniques, such as (spt)PALM, (u/DNA)PAINT and quantum dot tracking, have given unprecedented insight into the nanoscale molecular organization and dynamics in living cells. They allow monitoring individual proteins with millisecond temporal resolution and high spatial resolution (<30 nm) by precisely localizing the point spread function (PSF) of individual emitters and tracking their position over time. While SPT methods have been extended to study the temporal dynamics and co-organization of multiple proteins, conventional experimental setups are restricted in the number of proteins they can probe simultaneously and usually have to tradeoff between the number of colors, the spatio-temporal resolution, and the field of view. Yet, localizing and tracking several proteins simultaneously at high spatial and temporal resolution within large field of views can provide important biological insights. By employing a dual-objective spectral imaging configuration compatible with live cell imaging combined with dedicated computation tools, we demonstrate simultaneous 3D single particle localization and tracking of multiple distinct species over large field of views to be feasible without compromising spatio-temporal resolution. The dispersive element introduced into the second optical path induces a spectrally dependent displacement, which we used to analytically separate up to five different fluorescent species of single emitters based on their emission spectra. We used commercially available microscope bodies aligned one on top of the other, offering biologists with a very ergonomic and flexible instrument covering a broad range of SMLM applications. Finally, we developed a powerful freely available software, called PALMTracer, which allows to quantitatively assess 3D + t + λ SMLM data. We illustrate the capacity of our approach by performing multi-color 3D DNA-PAINT of fixed samples, and demonstrate simultaneous tracking of multiple receptors in live fibroblast and neuron cultures.
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Affiliation(s)
- Corey Butler
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
- Imagine Optic, Orsay, France
| | - G Ezequiel Saraceno
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
| | - Adel Kechkar
- Ecole Nationale Supérieure de Biotechnologie, Laboratoire de Bioengineering, Constantine, El Khroub, Algeria
| | - Nathan Bénac
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
| | - Vincent Studer
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
| | - Julien P. Dupuis
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
| | - Laurent Groc
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
| | - Rémi Galland
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
| | - Jean-Baptiste Sibarita
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297F-33000, F-33000, Bordeaux, France
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25
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Martens KJA, Turkowyd B, Endesfelder U. Raw Data to Results: A Hands-On Introduction and Overview of Computational Analysis for Single-Molecule Localization Microscopy. FRONTIERS IN BIOINFORMATICS 2022; 1:817254. [PMID: 36303761 PMCID: PMC9580916 DOI: 10.3389/fbinf.2021.817254] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/28/2021] [Indexed: 09/28/2023] Open
Abstract
Single-molecule localization microscopy (SMLM) is an advanced microscopy method that uses the blinking of fluorescent molecules to determine the position of these molecules with a resolution below the diffraction limit (∼5-40 nm). While SMLM imaging itself is becoming more popular, the computational analysis surrounding the technique is still a specialized area and often remains a "black box" for experimental researchers. Here, we provide an introduction to the required computational analysis of SMLM imaging, post-processing and typical data analysis. Importantly, user-friendly, ready-to-use and well-documented code in Python and MATLAB with exemplary data is provided as an interactive experience for the reader, as well as a starting point for further analysis. Our code is supplemented by descriptions of the computational problems and their implementation. We discuss the state of the art in computational methods and software suites used in SMLM imaging and data analysis. Finally, we give an outlook into further computational challenges in the field.
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Affiliation(s)
- Koen J. A. Martens
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, United States
- Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Bartosz Turkowyd
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, United States
- Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Ulrike Endesfelder
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, United States
- Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
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26
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McCann AJ, Lou J, Moustaqil M, Graus MS, Blum A, Fontaine F, Liu H, Luu W, Rudolffi-Soto P, Koopman P, Sierecki E, Gambin Y, Meunier FA, Liu Z, Hinde E, Francois M. A dominant-negative SOX18 mutant disrupts multiple regulatory layers essential to transcription factor activity. Nucleic Acids Res 2021; 49:10931-10955. [PMID: 34570228 PMCID: PMC8565327 DOI: 10.1093/nar/gkab820] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 08/18/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
Few genetically dominant mutations involved in human disease have been fully explained at the molecular level. In cases where the mutant gene encodes a transcription factor, the dominant-negative mode of action of the mutant protein is particularly poorly understood. Here, we studied the genome-wide mechanism underlying a dominant-negative form of the SOX18 transcription factor (SOX18RaOp) responsible for both the classical mouse mutant Ragged Opossum and the human genetic disorder Hypotrichosis-lymphedema-telangiectasia-renal defect syndrome. Combining three single-molecule imaging assays in living cells together with genomics and proteomics analysis, we found that SOX18RaOp disrupts the system through an accumulation of molecular interferences which impair several functional properties of the wild-type SOX18 protein, including its target gene selection process. The dominant-negative effect is further amplified by poisoning the interactome of its wild-type counterpart, which perturbs regulatory nodes such as SOX7 and MEF2C. Our findings explain in unprecedented detail the multi-layered process that underpins the molecular aetiology of dominant-negative transcription factor function.
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Affiliation(s)
- Alex J McCann
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jieqiong Lou
- School of Physics, Department of Biochemistry and Molecular Biology, Bio21, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Mehdi Moustaqil
- EMBL Australia Node in Single Molecule Science and School of Medical Sciences, The University of New South Wales, Sydney, NSW 1466, Australia
| | - Matthew S Graus
- The David Richmond Laboratory for Cardio-Vascular Development: gene regulation and editing, The Centenary Institute, Newtown, Sydney, NSW 2006, Australia
| | - Ailisa Blum
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Frank Fontaine
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Hui Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, United States
| | - Winnie Luu
- The David Richmond Laboratory for Cardio-Vascular Development: gene regulation and editing, The Centenary Institute, Newtown, Sydney, NSW 2006, Australia
| | - Paulina Rudolffi-Soto
- EMBL Australia Node in Single Molecule Science and School of Medical Sciences, The University of New South Wales, Sydney, NSW 1466, Australia
| | - Peter Koopman
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Emma Sierecki
- EMBL Australia Node in Single Molecule Science and School of Medical Sciences, The University of New South Wales, Sydney, NSW 1466, Australia
| | - Yann Gambin
- EMBL Australia Node in Single Molecule Science and School of Medical Sciences, The University of New South Wales, Sydney, NSW 1466, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, United States
| | - Elizabeth Hinde
- School of Physics, Department of Biochemistry and Molecular Biology, Bio21, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Mathias Francois
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.,The David Richmond Laboratory for Cardio-Vascular Development: gene regulation and editing, The Centenary Institute, Newtown, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
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27
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Mehidi A, Kage F, Karatas Z, Cercy M, Schaks M, Polesskaya A, Sainlos M, Gautreau AM, Rossier O, Rottner K, Giannone G. Forces generated by lamellipodial actin filament elongation regulate the WAVE complex during cell migration. Nat Cell Biol 2021; 23:1148-1162. [PMID: 34737443 DOI: 10.1038/s41556-021-00786-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 09/27/2021] [Indexed: 12/17/2022]
Abstract
Actin filaments generate mechanical forces that drive membrane movements during trafficking, endocytosis and cell migration. Reciprocally, adaptations of actin networks to forces regulate their assembly and architecture. Yet, a demonstration of forces acting on actin regulators at actin assembly sites in cells is missing. Here we show that local forces arising from actin filament elongation mechanically control WAVE regulatory complex (WRC) dynamics and function, that is, Arp2/3 complex activation in the lamellipodium. Single-protein tracking revealed WRC lateral movements along the lamellipodium tip, driven by elongation of actin filaments and correlating with WRC turnover. The use of optical tweezers to mechanically manipulate functional WRC showed that piconewton forces, as generated by single-filament elongation, dissociated WRC from the lamellipodium tip. WRC activation correlated with its trapping, dwell time and the binding strength at the lamellipodium tip. WRC crosslinking, hindering its mechanical dissociation, increased WRC dwell time and Arp2/3-dependent membrane protrusion. Thus, forces generated by individual actin filaments on their regulators can mechanically tune their turnover and hence activity during cell migration.
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Affiliation(s)
- Amine Mehidi
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Frieda Kage
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Zeynep Karatas
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Maureen Cercy
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Matthias Schaks
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Anna Polesskaya
- CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Matthieu Sainlos
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Alexis M Gautreau
- CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Olivier Rossier
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Grégory Giannone
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France.
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28
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Liouta K, Chabbert J, Benquet S, Tessier B, Studer V, Sainlos M, De Wit J, Thoumine O, Chamma I. Role of regulatory C-terminal motifs in synaptic confinement of LRRTM2. Biol Cell 2021; 113:492-506. [PMID: 34498765 DOI: 10.1111/boc.202100026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 12/25/2022]
Abstract
Leucine Rich Repeat Transmembrane proteins (LRRTMs) are neuronal cell adhesion molecules involved in synapse development and plasticity. LRRTM2 is the most synaptogenic isoform of the family, and its expression is strongly restricted to excitatory synapses in mature neurons. However, the mechanisms by which LRRTM2 is trafficked and stabilized at synapses remain unknown. Here, we examine the role of LRRTM2 intracellular domain on its membrane expression and stabilization at excitatory synapses, using a knock-down strategy combined to single molecule tracking and super-resolution dSTORM microscopy. We show that LRRTM2 operates an important shift in mobility after synaptogenesis in hippocampal neurons. Knock-down of LRRTM2 during synapse formation reduced excitatory synapse density in mature neurons. Deletion of LRRTM2 C-terminal domain abolished the compartmentalization of LRRTM2 in dendrites and disrupted its synaptic enrichment. Furtheremore, we show that LRRTM2 diffusion is increased in the absence of its intracellular domain, and that the protein is more dispersed at synapses. Surprisingly, LRRTM2 confinement at synapses was strongly dependent on a YxxC motif in the C-terminal domain, but was independent of the PDZ-like binding motif ECEV. Finally, the nanoscale organization of LRRTM2 at excitatory synapses depended on its C-terminal domain, with involvement of both the PDZ-binding and YxxC motifs. Altogether, these results demonstrate that LRRTM2 trafficking and enrichment at excitatory synapses are dependent on its intracellular domain.
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Affiliation(s)
- Konstantina Liouta
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Julia Chabbert
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Sebastien Benquet
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Béatrice Tessier
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Vincent Studer
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Matthieu Sainlos
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Joris De Wit
- VIB Center for Brain & Disease Research, Leuven, Belgium.,KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Olivier Thoumine
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Ingrid Chamma
- Interdisciplinary Institute for Neuroscience, Centre National de la Recherche Scientifique, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
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29
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Fazekas FJ, Shaw TR, Kim S, Bogucki RA, Veatch SL. A mean shift algorithm for drift correction in localization microscopy. BIOPHYSICAL REPORTS 2021; 1. [PMID: 35382035 PMCID: PMC8978553 DOI: 10.1016/j.bpr.2021.100008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Single-molecule localization microscopy techniques transcend the diffraction limit of visible light by localizing isolated emitters sampled stochastically. This time-lapse imaging necessitates long acquisition times, over which sample drift can become large relative to the localization precision. Here, we present an efficient and robust method for estimating drift, using a simple peak-finding algorithm based on mean shifts that is effective for single-molecule localization microscopy in two or three dimensions.
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30
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Vu XH, Dien ND, Pham TTH, Jaffiol R, Vézy C, Ca NX, Trang TT. Evaluation of diffusion coefficient of P-glycoprotein molecules labeled with green fluorescent protein in living cell membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183721. [PMID: 34352241 DOI: 10.1016/j.bbamem.2021.183721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/21/2021] [Accepted: 07/29/2021] [Indexed: 11/29/2022]
Abstract
The movement of individual molecules inside living cells has recently been resolved by single particles tracking (SPT) method which is a powerful tool for probing the organization and dynamics of the plasma membrane constituents. Effective treatment of metastatic cancers requires the toxic chemotherapy, however this therapy leads to the multidrug resistance phenomenon of the cancer cells, in which the cancer cells resist simultaneously to different drugs with different targets and chemical structures. P-glycoprotein molecules which are responsible for multidrug resistance of many cancer cells have been studied by cancer biologists during past haft of century. Recently, advances in laser and detector technologies have enabled single fluorophores to be visualized in aqueous solution. The development of the total internal reflection fluorescent microscope (TIRFM) provided means to monitor dynamic molecular localization in living cells. In this paper, P-glycoproteins (PGP) were labeled with green fluorescent protein (GFP) in living cell membrane of Madin-Darby canine kidney (MDCK) and the TIRFM method was used to characterize the dynamics of individual protein molecules on the surface of living cells. An evanescent field was produced by a totally internally reflected and a laser beam was illuminated the glass-water interface. GFP-PGP proteins that entered the evanescent field appeared as individual spots of light which were slighter than background fluorescence. We obtained high-resolution images and diffusion maps of membrane proteins on cell surface and showed the local diffusion properties of specific proteins on single cells. We also determined the diffusion coefficient, the mean square displacement and the average velocity of the tracked particles, as well as the heterogeneity of the cell environment. This study enabled us to understand single-molecule features in living cell and measure the diffusion kinetics of membrane-bound molecules.
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Affiliation(s)
- Xuan Hoa Vu
- Institute of Science and Technology, TNU- University of Sciences (TNUS), Tan Thinh ward, Thai Nguyen city, Viet Nam
| | - Nguyen Dac Dien
- Faculty of Labour Protection, Vietnam Trade Union University, 169 Tay Son street, Hanoi city, Viet Nam
| | - Thi Thu Ha Pham
- Faculty of Chemistry, TNU- University of Sciences (TNUS), Tan Thinh ward, Thai Nguyen city, Viet Nam.
| | - Rodolphe Jaffiol
- Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, UMR CNRS 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, CS 42060, 10 004 Troyes Cedex, France.
| | - Cyrille Vézy
- Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institut Charles Delaunay, UMR CNRS 6281, Université de Technologie de Troyes, 12 Rue Marie Curie, CS 42060, 10 004 Troyes Cedex, France
| | - Nguyen Xuan Ca
- Institute of Science and Technology, TNU- University of Sciences (TNUS), Tan Thinh ward, Thai Nguyen city, Viet Nam
| | - Tran Thu Trang
- Institute of Science and Technology, TNU- University of Sciences (TNUS), Tan Thinh ward, Thai Nguyen city, Viet Nam
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Xu J, Liu Y. Probing Chromatin Compaction and Its Epigenetic States in situ With Single-Molecule Localization-Based Super-Resolution Microscopy. Front Cell Dev Biol 2021; 9:653077. [PMID: 34178982 PMCID: PMC8222792 DOI: 10.3389/fcell.2021.653077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Chromatin organization play a vital role in gene regulation and genome maintenance in normal biological processes and in response to environmental insults. Disruption of chromatin organization imposes a significant effect on many cellular processes and is often associated with a range of pathological processes such as aging and cancer. Extensive attention has been attracted to understand the structural and functional studies of chromatin architecture. Biochemical assays coupled with the state-of-the-art genomic technologies have been traditionally used to probe chromatin architecture. Recent advances in single molecule localization microscopy (SMLM) open up new opportunities to directly visualize higher-order chromatin architecture, its compaction status and its functional states at nanometer resolution in the intact cells or tissue. In this review, we will first discuss the recent technical advantages and challenges of using SMLM to image chromatin architecture. Next, we will focus on the recent applications of SMLM for structural and functional studies to probe chromatin architecture in key cellular processes. Finally, we will provide our perspectives on the recent development and potential applications of super-resolution imaging of chromatin architecture in improving our understanding in diseases.
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Affiliation(s)
- Jianquan Xu
- Biomedical Optical Imaging Laboratory, Department of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Yang Liu
- Biomedical Optical Imaging Laboratory, Department of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- University of Pittsburgh Hillman Cancer Center, Pittsburgh, PA, United States
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32
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Kowalczyk GJ, Cruz JA, Guo Y, Zhang Q, Sauerwald N, Lee REC. dNEMO: a tool for quantification of mRNA and punctate structures in time-lapse images of single cells. Bioinformatics 2021; 37:677-683. [PMID: 33051642 DOI: 10.1093/bioinformatics/btaa874] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/20/2020] [Accepted: 09/28/2020] [Indexed: 11/14/2022] Open
Abstract
MOTIVATION Many biological processes are regulated by single molecules and molecular assemblies within cells that are visible by microscopy as punctate features, often diffraction limited. Here, we present detecting-NEMO (dNEMO), a computational tool optimized for accurate and rapid measurement of fluorescent puncta in fixed-cell and time-lapse images. RESULTS The spot detection algorithm uses the à trous wavelet transform, a computationally inexpensive method that is robust to imaging noise. By combining automated with manual spot curation in the user interface, fluorescent puncta can be carefully selected and measured against their local background to extract high-quality single-cell data. Integrated into the workflow are segmentation and spot-inspection tools that enable almost real-time interaction with images without time consuming pre-processing steps. Although the software is agnostic to the type of puncta imaged, we demonstrate dNEMO using smFISH to measure transcript numbers in single cells in addition to the transient formation of IKK/NEMO puncta from time-lapse images of cells exposed to inflammatory stimuli. We conclude that dNEMO is an ideal user interface for rapid and accurate measurement of fluorescent molecular assemblies in biological imaging data. AVAILABILITY AND IMPLEMENTATION The data and software are freely available online at https://github.com/recleelab. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Gabriel J Kowalczyk
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
| | - J Agustin Cruz
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
| | - Yue Guo
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA.,Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Qiuhong Zhang
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
| | - Natalie Sauerwald
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Robin E C Lee
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
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Orré T, Joly A, Karatas Z, Kastberger B, Cabriel C, Böttcher RT, Lévêque-Fort S, Sibarita JB, Fässler R, Wehrle-Haller B, Rossier O, Giannone G. Molecular motion and tridimensional nanoscale localization of kindlin control integrin activation in focal adhesions. Nat Commun 2021; 12:3104. [PMID: 34035280 PMCID: PMC8149821 DOI: 10.1038/s41467-021-23372-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/21/2021] [Indexed: 12/20/2022] Open
Abstract
Focal adhesions (FAs) initiate chemical and mechanical signals involved in cell polarity, migration, proliferation and differentiation. Super-resolution microscopy revealed that FAs are organized at the nanoscale into functional layers from the lower plasma membrane to the upper actin cytoskeleton. Yet, how FAs proteins are guided into specific nano-layers to promote interaction with given targets is unknown. Using single protein tracking, super-resolution microscopy and functional assays, we link the molecular behavior and 3D nanoscale localization of kindlin with its function in integrin activation inside FAs. We show that immobilization of integrins in FAs depends on interaction with kindlin. Unlike talin, kindlin displays free diffusion along the plasma membrane outside and inside FAs. We demonstrate that the kindlin Pleckstrin Homology domain promotes membrane diffusion and localization to the membrane-proximal integrin nano-layer, necessary for kindlin enrichment and function in FAs. Using kindlin-deficient cells, we show that kindlin membrane localization and diffusion are crucial for integrin activation, cell spreading and FAs formation. Thus, kindlin uses a different route than talin to reach and activate integrins, providing a possible molecular basis for their complementarity during integrin activation.
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Affiliation(s)
- Thomas Orré
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Adrien Joly
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Zeynep Karatas
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | - Birgit Kastberger
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, Geneva 4, Switzerland
| | - Clément Cabriel
- Institut des Sciences Moléculaires d'Orsay, CNRS UMR8214, Univ. Paris-Sud, Université Paris Saclay, Orsay, Cedex, France
| | | | - Sandrine Lévêque-Fort
- Institut des Sciences Moléculaires d'Orsay, CNRS UMR8214, Univ. Paris-Sud, Université Paris Saclay, Orsay, Cedex, France
| | - Jean-Baptiste Sibarita
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France
| | | | - Bernhard Wehrle-Haller
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, Geneva 4, Switzerland
| | - Olivier Rossier
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France.
| | - Grégory Giannone
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR, Bordeaux, France.
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Danial JSH, Shalaby R, Cosentino K, Mahmoud MM, Medhat F, Klenerman D, Garcia Saez AJ. DeepSinse: deep learning based detection of single molecules. Bioinformatics 2021; 37:3998-4000. [PMID: 33964131 DOI: 10.1093/bioinformatics/btab352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/14/2021] [Accepted: 05/06/2021] [Indexed: 11/14/2022] Open
Abstract
MOTIVATION Imaging single molecules has emerged as a powerful characterization tool in the biological sciences. The detection of these under various noise conditions requires the use of algorithms that are dependent on the end-user inputting several parameters, the choice of which can be challenging and subjective. RESULTS In this work, we propose DeepSinse, an easily-trainable and useable deep neural network that can detect single molecules with little human input and across a wide range of signal-to-noise ratios. We validate the neural network on the detection of single bursts in simulated and experimental data and compare its performance with the best-in-class, domain-specific algorithms. AVAILABILITY Ground truth ROI simulating code, neural network training, validation code, classification code, ROI picker, GUI for simulating, training and validating DeepSinse as well as pre-trained networks are all released under the MIT License on www.github.com/jdanial/DeepSinse.The dSTORM dataset processing code is released under the MIT License on www.github.com/jdanial/StormProcessor. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- John S H Danial
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.,UK Dementia Research Institute, University of Cambridge, Cambridge, United Kingdom
| | - Raed Shalaby
- Institute of Genetics, University of Cologne, Cologne, Germany
| | - Katia Cosentino
- Department of Biology, University of Osnabruck, Osnabruck, Germany
| | - Marwa M Mahmoud
- Department of Computer Science, University of Cambridge, Cambridge, United Kingdom
| | - Fady Medhat
- Department of Computer Science, University of York, York, United Kingdom
| | - David Klenerman
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.,UK Dementia Research Institute, University of Cambridge, Cambridge, United Kingdom
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Kuhn T, Hettich J, Davtyan R, Gebhardt JCM. Single molecule tracking and analysis framework including theory-predicted parameter settings. Sci Rep 2021; 11:9465. [PMID: 33947895 PMCID: PMC8096815 DOI: 10.1038/s41598-021-88802-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/16/2021] [Indexed: 02/02/2023] Open
Abstract
Imaging, tracking and analyzing individual biomolecules in living systems is a powerful technology to obtain quantitative kinetic and spatial information such as reaction rates, diffusion coefficients and localization maps. Common tracking tools often operate on single movies and require additional manual steps to analyze whole data sets or to compare different experimental conditions. We report a fast and comprehensive single molecule tracking and analysis framework (TrackIt) to simultaneously process several multi-movie data sets. A user-friendly GUI offers convenient tracking visualization, multiple state-of-the-art analysis procedures, display of results, and data im- and export at different levels to utilize external software tools. We applied our framework to quantify dissociation rates of a transcription factor in the nucleus and found that tracking errors, similar to fluorophore photobleaching, have to be considered for reliable analysis. Accordingly, we developed an algorithm, which accounts for both tracking losses and suggests optimized tracking parameters when evaluating reaction rates. Our versatile and extensible framework facilitates quantitative analysis of single molecule experiments at different experimental conditions.
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Affiliation(s)
- Timo Kuhn
- grid.6582.90000 0004 1936 9748Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Johannes Hettich
- grid.6582.90000 0004 1936 9748Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Rubina Davtyan
- grid.6582.90000 0004 1936 9748Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany ,grid.4514.40000 0001 0930 2361Present Address: NanoLund and Solid State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - J. Christof M. Gebhardt
- grid.6582.90000 0004 1936 9748Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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36
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Kedia S, Ramanan N, Nair D. Quantifying molecular aggregation by super resolution microscopy within an excitatory synapse from mouse hippocampal neurons. STAR Protoc 2021; 2:100470. [PMID: 33937876 PMCID: PMC8076707 DOI: 10.1016/j.xpro.2021.100470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Super-resolution microscopy (SRM) has been widely adopted to probe molecular distribution at excitatory synapses. We present an SRM paradigm to evaluate the nanoscale organization heterogeneity between neuronal subcompartments. Using mouse hippocampal neurons, we describe the identification of the morphological characteristics of nanodomains within functional zones of a single excitatory synapse. This information can be used to correlate structure and function at molecular resolution in single synapses. The protocol can be applied to immunocytochemical/histochemical samples across different imaging paradigms. For complete details on the use and execution of this protocol, please refer to Kedia et al. (2021).
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Affiliation(s)
- Shekhar Kedia
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India
| | | | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India
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37
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Dankovich TM, Rizzoli SO. Challenges facing quantitative large-scale optical super-resolution, and some simple solutions. iScience 2021; 24:102134. [PMID: 33665555 PMCID: PMC7898072 DOI: 10.1016/j.isci.2021.102134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Optical super-resolution microscopy (SRM) has enabled biologists to visualize cellular structures with near-molecular resolution, giving unprecedented access to details about the amounts, sizes, and spatial distributions of macromolecules in the cell. Precisely quantifying these molecular details requires large datasets of high-quality, reproducible SRM images. In this review, we discuss the unique set of challenges facing quantitative SRM, giving particular attention to the shortcomings of conventional specimen preparation techniques and the necessity for optimal labeling of molecular targets. We further discuss the obstacles to scaling SRM methods, such as lengthy image acquisition and complex SRM data analysis. For each of these challenges, we review the recent advances in the field that circumvent these pitfalls and provide practical advice to biologists for optimizing SRM experiments.
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Affiliation(s)
- Tal M. Dankovich
- University Medical Center Göttingen, Institute for Neuro- and Sensory Physiology, Göttingen 37073, Germany
- International Max Planck Research School for Neuroscience, Göttingen, Germany
| | - Silvio O. Rizzoli
- University Medical Center Göttingen, Institute for Neuro- and Sensory Physiology, Göttingen 37073, Germany
- Biostructural Imaging of Neurodegeneration (BIN) Center & Multiscale Bioimaging Excellence Center, Göttingen 37075, Germany
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38
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Codron P, Letournel F, Marty S, Renaud L, Bodin A, Duchesne M, Verny C, Lenaers G, Duyckaerts C, Julien J, Cassereau J, Chevrollier A. STochastic Optical Reconstruction Microscopy (STORM) reveals the nanoscale organization of pathological aggregates in human brain. Neuropathol Appl Neurobiol 2021; 47:127-142. [PMID: 32688444 PMCID: PMC7891317 DOI: 10.1111/nan.12646] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 07/12/2020] [Accepted: 07/12/2020] [Indexed: 12/31/2022]
Abstract
AIMS Histological analysis of brain tissue samples provides valuable information about the pathological processes leading to common neurodegenerative disorders. In this context, the development of novel high-resolution imaging approaches is a current challenge in neuroscience. METHODS To this end, we used a recent super-resolution imaging technique called STochastic Optical Reconstruction Microscopy (STORM) to analyse human brain sections. We combined STORM cell imaging protocols with neuropathological techniques to image cryopreserved brain samples from control subjects and patients with neurodegenerative diseases. RESULTS This approach allowed us to perform 2D-, 3D- and two-colour-STORM in neocortex, white matter and brainstem samples. STORM proved to be particularly effective at visualizing the organization of dense protein inclusions and we imaged with a <50 nm resolution pathological aggregates within the central nervous system of patients with Alzheimer's disease, Parkinson's disease, Lewy body dementia and fronto-temporal lobar degeneration. Aggregated Aβ branches appeared reticulated and cross-linked in the extracellular matrix, with widths from 60 to 240 nm. Intraneuronal Tau and TDP-43 inclusions were denser, with a honeycomb pattern in the soma and a filamentous organization in the axons. Finally, STORM imaging of α-synuclein pathology revealed the internal organization of Lewy bodies that could not be observed by conventional fluorescence microscopy. CONCLUSIONS STORM imaging of human brain samples opens further gates to a more comprehensive understanding of common neurological disorders. The convenience of this technique should open a straightforward extension of its application for super-resolution imaging of the human brain, with promising avenues to current challenges in neuroscience.
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Affiliation(s)
- P. Codron
- Service de NeurologieCentre Hospitalier Universitaire d’AngersAngersFrance
- Laboratoire de Neurobiologie et NeuropathologieCentre Hospitalier Universitaire d’AngersAngersFrance
- Équipe MitolabInstitut MITOVASCINSERM U1083CNRS 6015Université d'AngersAngersFrance
| | - F. Letournel
- Service de NeurologieCentre Hospitalier Universitaire d’AngersAngersFrance
- Laboratoire de Neurobiologie et NeuropathologieCentre Hospitalier Universitaire d’AngersAngersFrance
| | - S. Marty
- Institut du Cerveau et de la Moelle épinièreINSERM U1127CNRS UMR7225Sorbonne UniversitéParisFrance
| | - L. Renaud
- CERVO Brain Research Centre2601 Chemin de la CanardièreQuébecQCCanada
| | - A. Bodin
- Équipe MitolabInstitut MITOVASCINSERM U1083CNRS 6015Université d'AngersAngersFrance
| | - M. Duchesne
- Laboratoire d'Anatomie PathologiqueCentre Hospitalier Universitaire DupuytrenLimogesFrance
- Centre de Référence des Neuropathies Périphériques RaresCentre Hospitalier Universitaire DupuytrenLimogesFrance
| | - C. Verny
- Service de NeurologieCentre Hospitalier Universitaire d’AngersAngersFrance
- Équipe MitolabInstitut MITOVASCINSERM U1083CNRS 6015Université d'AngersAngersFrance
| | - G. Lenaers
- Équipe MitolabInstitut MITOVASCINSERM U1083CNRS 6015Université d'AngersAngersFrance
| | - C. Duyckaerts
- Institut du Cerveau et de la Moelle épinièreINSERM U1127CNRS UMR7225Sorbonne UniversitéParisFrance
| | - J.‐P. Julien
- CERVO Brain Research Centre2601 Chemin de la CanardièreQuébecQCCanada
- Department of Psychiatry and NeuroscienceLaval UniversityQuébecQCCanada
| | - J. Cassereau
- Service de NeurologieCentre Hospitalier Universitaire d’AngersAngersFrance
- Équipe MitolabInstitut MITOVASCINSERM U1083CNRS 6015Université d'AngersAngersFrance
| | - A. Chevrollier
- Équipe MitolabInstitut MITOVASCINSERM U1083CNRS 6015Université d'AngersAngersFrance
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Affiliation(s)
| | - Marc Hoffmann
- Université Paris-Dauphine & PSL, CNRS CEREMADE, 75016 Paris, France
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40
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Affiliation(s)
| | - Marc Hoffmann
- Université Paris-Dauphine & PSL, CNRS CEREMADE, 75016 Paris, France
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41
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Single-Protein Tracking to Study Protein Interactions During Integrin-Based Migration. Methods Mol Biol 2021; 2217:85-113. [PMID: 33215379 DOI: 10.1007/978-1-0716-0962-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Cell migration is a complex biophysical process which involves the coordination of molecular assemblies including integrin-dependent adhesions, signaling networks and force-generating cytoskeletal structures incorporating both actin polymerization and myosin activity. During the last decades, proteomic studies have generated impressive protein-protein interaction maps, although the subcellular location, duration, strength, sequence, and nature of these interactions are still concealed. In this chapter we describe how recent developments in superresolution microscopy (SRM) and single-protein tracking (SPT) start to unravel protein interactions and actions in subcellular molecular assemblies driving cell migration.
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42
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High-speed super-resolution imaging of rotationally symmetric structures using SPEED microscopy and 2D-to-3D transformation. Nat Protoc 2020; 16:532-560. [PMID: 33318694 DOI: 10.1038/s41596-020-00440-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/09/2020] [Indexed: 02/05/2023]
Abstract
Various super-resolution imaging techniques have been developed to break the diffraction-limited resolution of light microscopy. However, it still remains challenging to obtain three-dimensional (3D) super-resolution information of structures and dynamic processes in live cells at high speed. We recently developed high-speed single-point edge-excitation sub-diffraction (SPEED) microscopy and its two-dimensional (2D)-to-3D transformation algorithm to provide an effective approach to achieving 3D sub-diffraction-limit information in subcellular structures and organelles that have rotational symmetry. In contrast to most other 3D super-resolution microscopy or 3D particle-tracking microscopy approaches, SPEED microscopy does not depend on complex optical components and can be implemented onto a standard inverted epifluorescence microscope. SPEED microscopy is specifically designed to obtain 2D spatial locations of individual immobile or moving fluorescent molecules inside sub-micrometer biological channels or cavities at high spatiotemporal resolution. After data collection, post-localization 2D-to-3D transformation is applied to obtain 3D super-resolution structural and dynamic information. The complete protocol, including cell culture and sample preparation (6-7 d), SPEED imaging (4-5 h), data analysis and validation through simulation (5-13 h), takes ~9 d to complete.
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43
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Vissa A, Giuliani M, Kim PK, Yip CM. Hyperspectral super-resolution imaging with far-red emitting fluorophores using a thin-film tunable filter. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:123703. [PMID: 33379995 DOI: 10.1063/1.5143319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
New innovations in single-molecule localization microscopy (SMLM) have revolutionized optical imaging, enabling the characterization of biological structures and interactions with unprecedented detail and resolution. However, multi-color or hyperspectral SMLM can pose particular challenges which affect image quality and data interpretation, such as unequal photophysical performance of fluorophores and non-linear image registration issues, which arise as two emission channels travel along different optical paths to reach the detector. In addition, using evanescent-wave based approaches (Total Internal Reflection Fluorescence: TIRF) where beam shape, decay depth, and power density are important, different illumination wavelengths can lead to unequal imaging depth across multiple channels on the same sample. A potential useful approach would be to use a single excitation wavelength to perform hyperspectral localization imaging. We report herein on the use of a variable angle tunable thin-film filter to spectrally isolate far-red emitting fluorophores. This solution was integrated into a commercial microscope platform using an open-source hardware design, enabling the rapid acquisition of SMLM images arising from fluorescence emission captured within ∼15 nm to 20 nm spectral windows (or detection bands). By characterizing intensity distributions, average intensities, and localization frequency through a range of spectral windows, we investigated several far-red emitting fluorophores and identified an optimal fluorophore pair for two-color SMLM using this method. Fluorophore crosstalk between the different spectral windows was assessed by examining the effect of varying the photon output thresholds on the localization frequency and fraction of data recovered. The utility of this approach was demonstrated by hyper-spectral super-resolution imaging of the interaction between the mitochondrial protein, TOM20, and the peroxisomal protein, PMP70.
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Affiliation(s)
- Adriano Vissa
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Maximiliano Giuliani
- Institute for Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Peter K Kim
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Christopher M Yip
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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FluoSim: simulator of single molecule dynamics for fluorescence live-cell and super-resolution imaging of membrane proteins. Sci Rep 2020; 10:19954. [PMID: 33203884 PMCID: PMC7672080 DOI: 10.1038/s41598-020-75814-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022] Open
Abstract
Fluorescence live-cell and super-resolution microscopy methods have considerably advanced our understanding of the dynamics and mesoscale organization of macro-molecular complexes that drive cellular functions. However, different imaging techniques can provide quite disparate information about protein motion and organization, owing to their respective experimental ranges and limitations. To address these issues, we present here a robust computer program, called FluoSim, which is an interactive simulator of membrane protein dynamics for live-cell imaging methods including SPT, FRAP, PAF, and FCS, and super-resolution imaging techniques such as PALM, dSTORM, and uPAINT. FluoSim integrates diffusion coefficients, binding rates, and fluorophore photo-physics to calculate in real time the localization and intensity of thousands of independent molecules in 2D cellular geometries, providing simulated data directly comparable to actual experiments. FluoSim was thoroughly validated against experimental data obtained on the canonical neurexin-neuroligin adhesion complex at cell-cell contacts. This unified software allows one to model and predict membrane protein dynamics and localization at the ensemble and single molecule level, so as to reconcile imaging paradigms and quantitatively characterize protein behavior in complex cellular environments.
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45
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TSPAN5 Enriched Microdomains Provide a Platform for Dendritic Spine Maturation through Neuroligin-1 Clustering. Cell Rep 2020; 29:1130-1146.e8. [PMID: 31665629 PMCID: PMC6899445 DOI: 10.1016/j.celrep.2019.09.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/09/2019] [Accepted: 09/18/2019] [Indexed: 12/21/2022] Open
Abstract
Tetraspanins are a class of evolutionarily conserved transmembrane proteins with 33 members identified in mammals that have the ability to organize specific membrane domains, named tetraspanin-enriched microdomains (TEMs). Despite the relative abundance of different tetraspanins in the CNS, few studies have explored their role at synapses. Here, we investigate the function of TSPAN5, a member of the tetraspanin superfamily for which mRNA transcripts are found at high levels in the mouse brain. We demonstrate that TSPAN5 is localized in dendritic spines of pyramidal excitatory neurons and that TSPAN5 knockdown induces a dramatic decrease in spine number because of defects in the spine maturation process. Moreover, we show that TSPAN5 interacts with the postsynaptic adhesion molecule neuroligin-1, promoting its correct surface clustering. We propose that membrane compartmentalization by tetraspanins represents an additional mechanism for regulating excitatory synapses. TSPAN5 is expressed in pyramidal neurons and localizes mainly to dendritic spines TSPAN5 interacts with neuroligin-1 and promotes its clustering TSPAN5-neuroligin-1 complex is fundamental for dendritic spine maturation
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Fricke S, Metzdorf K, Ohm M, Haak S, Heine M, Korte M, Zagrebelsky M. Fast Regulation of GABA AR Diffusion Dynamics by Nogo-A Signaling. Cell Rep 2020; 29:671-684.e6. [PMID: 31618635 DOI: 10.1016/j.celrep.2019.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/02/2019] [Accepted: 09/06/2019] [Indexed: 12/29/2022] Open
Abstract
Precisely controlling the excitatory and inhibitory balance is crucial for the stability and information-processing ability of neuronal networks. However, the molecular mechanisms maintaining this balance during ongoing sensory experiences are largely unclear. We show that Nogo-A signaling reciprocally regulates excitatory and inhibitory transmission. Loss of function for Nogo-A signaling through S1PR2 rapidly increases GABAAR diffusion, thereby decreasing their number at synaptic sites and the amplitude of GABAergic mIPSCs at CA3 hippocampal neurons. This increase in GABAAR diffusion rate is correlated with an increase in Ca2+ influx and requires the calcineurin-mediated dephosphorylation of the γ2 subunit at serine 327. These results suggest that Nogo-A signaling rapidly strengthens inhibitory GABAergic transmission by restricting the diffusion dynamics of GABAARs. Together with the observation that Nogo-A signaling regulates excitatory transmission in an opposite manner, these results suggest a crucial role for Nogo-A signaling in modulating the excitation and inhibition balance to restrict synaptic plasticity.
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Affiliation(s)
- Steffen Fricke
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Kristin Metzdorf
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Melanie Ohm
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Stefan Haak
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Martin Heine
- Molecular Physiology Group, Leibniz Institute of Neurobiology, Magdeburg 39118, Germany; Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Martin Korte
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany; Helmholtz Centre for Infection Research, AG NIND, Inhoffenstr. 7, Braunschweig 38124, Germany
| | - Marta Zagrebelsky
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany.
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Martens KJA, Jabermoradi A, Yang S, Hohlbein J. Integrating engineered point spread functions into the phasor-based single-molecule localization microscopy framework. Methods 2020; 193:107-115. [PMID: 32745620 DOI: 10.1016/j.ymeth.2020.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/17/2020] [Accepted: 07/27/2020] [Indexed: 10/23/2022] Open
Abstract
In single-molecule localization microscopy (SMLM), the use of engineered point spread functions (PSFs) provides access to three-dimensional localization information. The conventional approach of fitting PSFs with a single 2-dimensional Gaussian profile, however, often falls short in analyzing complex PSFs created by placing phase masks, deformable mirrors or spatial light modulators in the optical detection pathway. Here, we describe the integration of PSF modalities known as double-helix, saddle-point or tetra-pod into the phasor-based SMLM (pSMLM) framework enabling fast CPU based localization of single-molecule emitters with sub-pixel accuracy in three dimensions. For the double-helix PSF, pSMLM identifies the two individual lobes and uses their relative rotation for obtaining z-resolved localizations. For the analysis of saddle-point or tetra-pod PSFs, we present a novel phasor-based deconvolution approach entitled circular-tangent pSMLM. Saddle-point PSFs were experimentally realized by placing a deformable mirror in the Fourier plane and modulating the incoming wavefront with specific Zernike modes. Our pSMLM software package delivers similar precision and recall rates to the best-in-class software package (SMAP) at signal-to-noise ratios typical for organic fluorophores and achieves localization rates of up to 15 kHz (double-helix) and 250 kHz (saddle-point/tetra-pod) on a standard CPU. We further integrated pSMLM into an existing software package (SMALL-LABS) suitable for single-particle imaging and tracking in environments with obscuring backgrounds. Taken together, we provide a powerful hardware and software environment for advanced single-molecule studies.
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Affiliation(s)
- Koen J A Martens
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands; Laboratory of Bionanotechnology, Wageningen University and Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Abbas Jabermoradi
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Suyeon Yang
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Johannes Hohlbein
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands; Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
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48
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Massou S, Nunes Vicente F, Wetzel F, Mehidi A, Strehle D, Leduc C, Voituriez R, Rossier O, Nassoy P, Giannone G. Cell stretching is amplified by active actin remodelling to deform and recruit proteins in mechanosensitive structures. Nat Cell Biol 2020; 22:1011-1023. [PMID: 32719553 DOI: 10.1038/s41556-020-0548-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 06/22/2020] [Indexed: 02/07/2023]
Abstract
Detection and conversion of mechanical forces into biochemical signals controls cell functions during physiological and pathological processes. Mechanosensing is based on protein deformations and reorganizations, yet the molecular mechanisms are still unclear. Using a cell-stretching device compatible with super-resolution microscopy and single-protein tracking, we explored the nanoscale deformations and reorganizations of individual proteins inside mechanosensitive structures. We achieved super-resolution microscopy after live stretching on intermediate filaments, microtubules and integrin adhesions. Simultaneous single-protein tracking and stretching showed that while integrins followed the elastic deformation of the substrate, actin filaments and talin also displayed lagged and transient inelastic responses associated with active acto-myosin remodelling and talin deformations. Capturing acute reorganizations of single molecules during stretching showed that force-dependent vinculin recruitment is delayed and depends on the maturation of integrin adhesions. Thus, cells respond to external forces by amplifying transiently and locally cytoskeleton displacements, enabling protein deformation and recruitment in mechanosensitive structures.
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Affiliation(s)
- Sophie Massou
- Interdisciplinary Institute for Neuroscience, UMR 5297, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, UMR 5297, CNRS, Bordeaux, France
| | - Filipe Nunes Vicente
- Interdisciplinary Institute for Neuroscience, UMR 5297, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, UMR 5297, CNRS, Bordeaux, France
| | - Franziska Wetzel
- Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Université de Bordeaux, Talence, France.,Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Institut d'Optique and CNRS, Talence, France
| | - Amine Mehidi
- Interdisciplinary Institute for Neuroscience, UMR 5297, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, UMR 5297, CNRS, Bordeaux, France
| | - Dan Strehle
- Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Université de Bordeaux, Talence, France.,Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Institut d'Optique and CNRS, Talence, France
| | - Cecile Leduc
- Cell Polarity, Migration and Cancer Unit, UMR 3691, Institut Pasteur Paris and CNRS, Paris, France
| | - Raphaël Voituriez
- Laboratoire Jean Perrin and Laboratoire de Physique Théorique de la Matière Condensée, CNRS - Sorbonne Université, Paris, France
| | - Olivier Rossier
- Interdisciplinary Institute for Neuroscience, UMR 5297, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, UMR 5297, CNRS, Bordeaux, France
| | - Pierre Nassoy
- Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Université de Bordeaux, Talence, France.,Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Institut d'Optique and CNRS, Talence, France
| | - Grégory Giannone
- Interdisciplinary Institute for Neuroscience, UMR 5297, Université de Bordeaux, Bordeaux, France. .,Interdisciplinary Institute for Neuroscience, UMR 5297, CNRS, Bordeaux, France.
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Escamilla-Ayala AA, Sannerud R, Mondin M, Poersch K, Vermeire W, Paparelli L, Berlage C, Koenig M, Chavez-Gutierrez L, Ulbrich MH, Munck S, Mizuno H, Annaert W. Super-resolution microscopy reveals majorly mono- and dimeric presenilin1/γ-secretase at the cell surface. eLife 2020; 9:56679. [PMID: 32631487 PMCID: PMC7340497 DOI: 10.7554/elife.56679] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/15/2020] [Indexed: 12/17/2022] Open
Abstract
γ-Secretase is a multi-subunit enzyme whose aberrant activity is associated with Alzheimer’s disease and cancer. While its structure is atomically resolved, γ-secretase localization in the membrane in situ relies mostly on biochemical data. Here, we combined fluorescent tagging of γ-secretase subunits with super-resolution microscopy in fibroblasts. Structured illumination microscopy revealed single γ-secretase complexes with a monodisperse distribution and in a 1:1 stoichiometry of PSEN1 and nicastrin subunits. In living cells, sptPALM revealed PSEN1/γ-secretase mainly with directed motility and frequenting ‘hotspots’ or high track-density areas that are sensitive to γ-secretase inhibitors. We visualized γ-secretase association with substrates like amyloid precursor protein and N-cadherin, but not with its sheddases ADAM10 or BACE1 at the cell surface, arguing against pre-formed megadalton complexes. Nonetheless, in living cells PSEN1/γ-secretase transiently visits ADAM10 hotspots. Our results highlight the power of super-resolution microscopy for the study of γ-secretase distribution and dynamics in the membrane.
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Affiliation(s)
- Abril Angélica Escamilla-Ayala
- Laboratory for Membrane Trafficking, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Ragna Sannerud
- Laboratory for Membrane Trafficking, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Magali Mondin
- Bordeaux Imaging Center, UMS 3420, CNRS-University of Bordeaux, US4 INSERM, Bordeaux, France
| | - Karin Poersch
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Wendy Vermeire
- Laboratory for Membrane Trafficking, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Laura Paparelli
- Laboratory for Membrane Trafficking, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,VIB Bio Imaging Core, Leuven, Belgium
| | - Caroline Berlage
- Einstein Center for Neurosciences, NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Lucia Chavez-Gutierrez
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Laboratory of Proteolytic Mechanisms in Neurodegeneration, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
| | - Maximilian H Ulbrich
- Institute of Internal Medicine IV, Medical Center of the University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Sebastian Munck
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,VIB Bio Imaging Core, Leuven, Belgium
| | - Hideaki Mizuno
- Laboratory of Biomolecular Network Dynamics, Biochemistry, Molecular and Structural Biology Section, KU Leuven, Heverlee, Belgium
| | - Wim Annaert
- Laboratory for Membrane Trafficking, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
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50
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Ma H, Liu Y. Super-resolution localization microscopy: Toward high throughput, high quality, and low cost. APL PHOTONICS 2020; 5:060902. [PMID: 34350342 PMCID: PMC8330581 DOI: 10.1063/5.0011731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
After nearly 15 years since its initial debut, super-resolution localization microscopy that surpasses the diffraction-limited resolution barrier of optical microscopy has rapidly gotten out of the ivory tower and entered a new phase to address various challenging biomedical questions. Recent advances in this technology greatly increased the imaging throughput, improved the imaging quality, simplified the sample preparation, and reduced the system cost, making this technology suitable for routine biomedical research. We will provide our perspective on the recent technical advances and their implications in serving the community of biomedical research.
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Affiliation(s)
- Hongqiang Ma
- Biomedical Optical Imaging Laboratory, Departments of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Yang Liu
- Biomedical Optical Imaging Laboratory, Departments of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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