201
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Kuchenov D, Laketa V, Stein F, Salopiata F, Klingmüller U, Schultz C. High-Content Imaging Platform for Profiling Intracellular Signaling Network Activity in Living Cells. Cell Chem Biol 2016; 23:1550-1559. [PMID: 27939899 PMCID: PMC5193178 DOI: 10.1016/j.chembiol.2016.11.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 09/19/2016] [Accepted: 11/14/2016] [Indexed: 01/06/2023]
Abstract
Essential characteristics of cellular signaling networks include a complex interconnected architecture and temporal dynamics of protein activity. The latter can be monitored by Förster resonance energy transfer (FRET) biosensors at a single-live-cell level with high temporal resolution. However, these experiments are typically limited to the use of a couple of FRET biosensors. Here, we describe a FRET-based multi-parameter imaging platform (FMIP) that allows simultaneous high-throughput monitoring of multiple signaling pathways. We apply FMIP to monitor the crosstalk between epidermal growth factor receptor (EGFR) and insulin-like growth factor-1 receptor signaling, signaling perturbations caused by pathophysiologically relevant EGFR mutations, and the effects of a clinically important MEK inhibitor (selumetinib) on the EGFR network. We expect that in the future the platform will be applied to develop comprehensive models of signaling networks and will help to investigate the mechanism of action as well as side effects of therapeutic treatments.
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Affiliation(s)
- Dmitry Kuchenov
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Vibor Laketa
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Frank Stein
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Florian Salopiata
- Division of Systems Biology of Signal Transduction, Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), 69120 Heidelberg, Germany
| | - Ursula Klingmüller
- Division of Systems Biology of Signal Transduction, Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), 69120 Heidelberg, Germany
| | - Carsten Schultz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany; Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), 69120 Heidelberg, Germany; Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97201, USA.
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202
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Alonso MT, Rojo-Ruiz J, Navas-Navarro P, Rodríguez-Prados M, García-Sancho J. Measuring Ca 2+ inside intracellular organelles with luminescent and fluorescent aequorin-based sensors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:894-899. [PMID: 27939433 DOI: 10.1016/j.bbamcr.2016.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 02/06/2023]
Abstract
GFP-Aequorin Protein (GAP) can be used to measure [Ca2+] inside intracellular organelles, both by luminescence and by fluorescence. The low-affinity variant GAP3 is adequate for ratiometric imaging in the endoplasmic reticulum and Golgi apparatus, and it can be combined with conventional synthetic indicators for simultaneous measurements of cytosolic Ca2+. GAP is bioorthogonal as it does not have mammalian homologues, and it is robust and functionally expressed in transgenic flies and mice, where it can be used for Ca2+ measurements ex vivo and in vivo to explore animal models of health and disease. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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Affiliation(s)
- María Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain.
| | - Jonathan Rojo-Ruiz
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain
| | - Paloma Navas-Navarro
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain
| | - Macarena Rodríguez-Prados
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain
| | - Javier García-Sancho
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain.
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203
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Specht EA, Braselmann E, Palmer AE. A Critical and Comparative Review of Fluorescent Tools for Live-Cell Imaging. Annu Rev Physiol 2016; 79:93-117. [PMID: 27860833 DOI: 10.1146/annurev-physiol-022516-034055] [Citation(s) in RCA: 259] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fluorescent tools have revolutionized our ability to probe biological dynamics, particularly at the cellular level. Fluorescent sensors have been developed on several platforms, utilizing either small-molecule dyes or fluorescent proteins, to monitor proteins, RNA, DNA, small molecules, and even cellular properties, such as pH and membrane potential. We briefly summarize the impressive history of tool development for these various applications and then discuss the most recent noteworthy developments in more detail. Particular emphasis is placed on tools suitable for single-cell analysis and especially live-cell imaging applications. Finally, we discuss prominent areas of need in future fluorescent tool development-specifically, advancing our capability to analyze and integrate the plethora of high-content data generated by fluorescence imaging.
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Affiliation(s)
- Elizabeth A Specht
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80303; .,BioFrontiers Institute, University of Colorado, Boulder, Colorado 80303
| | - Esther Braselmann
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80303; .,BioFrontiers Institute, University of Colorado, Boulder, Colorado 80303
| | - Amy E Palmer
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80303; .,BioFrontiers Institute, University of Colorado, Boulder, Colorado 80303
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204
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Yang J, Cumberbatch D, Centanni S, Shi SQ, Winder D, Webb D, Johnson CH. Coupling optogenetic stimulation with NanoLuc-based luminescence (BRET) Ca ++ sensing. Nat Commun 2016; 7:13268. [PMID: 27786307 PMCID: PMC5476805 DOI: 10.1038/ncomms13268] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 09/13/2016] [Indexed: 11/09/2022] Open
Abstract
Optogenetic techniques allow intracellular manipulation of Ca++ by illumination of light-absorbing probe molecules such as channelrhodopsins and melanopsins. The consequences of optogenetic stimulation would optimally be recorded by non-invasive optical methods. However, most current optical methods for monitoring Ca++ levels are based on fluorescence excitation that can cause unwanted stimulation of the optogenetic probe and other undesirable effects such as tissue autofluorescence. Luminescence is an alternate optical technology that avoids the problems associated with fluorescence. Using a new bright luciferase, we here develop a genetically encoded Ca++ sensor that is ratiometric by virtue of bioluminescence resonance energy transfer (BRET). This sensor has a large dynamic range and partners optimally with optogenetic probes. Ca++ fluxes that are elicited by brief pulses of light to cultured cells expressing melanopsin and to neurons-expressing channelrhodopsin are quantified and imaged with the BRET Ca++ sensor in darkness, thereby avoiding undesirable consequences of fluorescence irradiation.
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Affiliation(s)
- Jie Yang
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
| | - Derrick Cumberbatch
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
| | - Samuel Centanni
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
| | - Shu-Qun Shi
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
| | - Danny Winder
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
| | - Donna Webb
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
| | - Carl Hirschie Johnson
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235-1634, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37235-1634, USA
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205
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Transplanted embryonic neurons integrate into adult neocortical circuits. Nature 2016; 539:248-253. [DOI: 10.1038/nature20113] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 09/23/2016] [Indexed: 12/19/2022]
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206
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Bolbat A, Schultz C. Recent developments of genetically encoded optical sensors for cell biology. Biol Cell 2016; 109:1-23. [PMID: 27628952 DOI: 10.1111/boc.201600040] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/06/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022]
Abstract
Optical sensors are powerful tools for live cell research as they permit to follow the location, concentration changes or activities of key cellular players such as lipids, ions and enzymes. Most of the current sensor probes are based on fluorescence which provides great spatial and temporal precision provided that high-end microscopy is used and that the timescale of the event of interest fits the response time of the sensor. Many of the sensors developed in the past 20 years are genetically encoded. There is a diversity of designs leading to simple or sometimes complicated applications for the use in live cells. Genetically encoded sensors began to emerge after the discovery of fluorescent proteins, engineering of their improved optical properties and the manipulation of their structure through application of circular permutation. In this review, we will describe a variety of genetically encoded biosensor concepts, including those for intensiometric and ratiometric sensors based on single fluorescent proteins, Forster resonance energy transfer-based sensors, sensors utilising bioluminescence, sensors using self-labelling SNAP- and CLIP-tags, and finally tetracysteine-based sensors. We focus on the newer developments and discuss the current approaches and techniques for design and application. This will demonstrate the power of using optical sensors in cell biology and will help opening the field to more systematic applications in the future.
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Affiliation(s)
- Andrey Bolbat
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Heidelberg, 69117, Germany
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Heidelberg, 69117, Germany
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207
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Wang F, Bélanger E, Paquet ME, Côté DC, De Koninck Y. Probing pain pathways with light. Neuroscience 2016; 338:248-271. [PMID: 27702648 DOI: 10.1016/j.neuroscience.2016.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 02/06/2023]
Abstract
We have witnessed an accelerated growth of photonics technologies in recent years to enable not only monitoring the activity of specific neurons, while animals are performing certain types of behavior, but also testing whether specific cells, circuits, and regions are sufficient or necessary for initiating, maintaining, or altering this or that behavior. Compared to other sensory systems, however, such as the visual or olfactory system, photonics applications in pain research are only beginning to emerge. One reason pain studies have lagged behind is that many of the techniques originally developed cannot be directly implemented to study key relay sites within pain pathways, such as the skin, dorsal root ganglia, spinal cord, and brainstem. This is due, in part, to difficulties in accessing these structures with light. Here we review a number of recent advances in design and delivery of light-sensitive molecular probes (sensors and actuators) into pain relay circuits to help decipher their structural and functional organization. We then discuss several challenges that have hampered hardware access to specific structures including light scattering, tissue movement and geometries. We review a number of strategies to circumvent these challenges, by delivering light into, and collecting it from the different key sites to unravel how nociceptive signals are encoded at each level of the neuraxis. We conclude with an outlook on novel imaging modalities for label-free chemical detection and opportunities for multimodal interrogation in vivo. While many challenges remain, these advances offer unprecedented opportunities to bridge cellular approaches with context-relevant behavioral testing, an essential step toward improving translation of basic research findings into clinical applications.
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Affiliation(s)
- Feng Wang
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada
| | - Erik Bélanger
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada
| | - Marie-Eve Paquet
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Département de biochimie, microbiologie et bioinformatique, Université Laval, Québec, QC, Canada
| | - Daniel C Côté
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de physique, de génie physique et d'optique, Université Laval, Québec, QC, Canada
| | - Yves De Koninck
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de psychiatrie et neurosciences, Université Laval, Québec, QC, Canada.
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208
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Day RN, Tao W, Dunn KW. A simple approach for measuring FRET in fluorescent biosensors using two-photon microscopy. Nat Protoc 2016; 11:2066-80. [DOI: 10.1038/nprot.2016.121] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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209
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Barykina NV, Subach OM, Doronin DA, Sotskov VP, Roshchina MA, Kunitsyna TA, Malyshev AY, Smirnov IV, Azieva AM, Sokolov IS, Piatkevich KD, Burtsev MS, Varizhuk AM, Pozmogova GE, Anokhin KV, Subach FV, Enikolopov GN. A new design for a green calcium indicator with a smaller size and a reduced number of calcium-binding sites. Sci Rep 2016; 6:34447. [PMID: 27677952 PMCID: PMC5039633 DOI: 10.1038/srep34447] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/14/2016] [Indexed: 11/18/2022] Open
Abstract
Genetically encoded calcium indicators (GECIs) are mainly represented by two- or one-fluorophore-based sensors. One type of two-fluorophore-based sensor, carrying Opsanus troponin C (TnC) as the Ca2+-binding moiety, has two binding sites for calcium ions, providing a linear response to calcium ions. One-fluorophore-based sensors have four Ca2+-binding sites but are better suited for in vivo experiments. Herein, we describe a novel design for a one-fluorophore-based GECI with two Ca2+-binding sites. The engineered sensor, called NTnC, uses TnC as the Ca2+-binding moiety, inserted in the mNeonGreen fluorescent protein. Monomeric NTnC has higher brightness and pH-stability in vitro compared with the standard GECI GCaMP6s. In addition, NTnC shows an inverted fluorescence response to Ca2+. Using NTnC, we have visualized Ca2+ dynamics during spontaneous activity of neuronal cultures as confirmed by control NTnC and its mutant, in which the affinity to Ca2+ is eliminated. Using whole-cell patch clamp, we have demonstrated that NTnC dynamics in neurons are similar to those of GCaMP6s and allow robust detection of single action potentials. Finally, we have used NTnC to visualize Ca2+ neuronal activity in vivo in the V1 cortical area in awake and freely moving mice using two-photon microscopy or an nVista miniaturized microscope.
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Affiliation(s)
- Natalia V Barykina
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia.,Department of Systems Neurobiology and Functional Neurochemistry, P.K. Anokhin Institute of Normal Physiology of RAMS, Moscow 125009, Russia
| | - Oksana M Subach
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia.,National Research Center "Kurchatov Institute", Moscow 123182, Russia
| | - Danila A Doronin
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia.,National Research Center "Kurchatov Institute", Moscow 123182, Russia
| | - Vladimir P Sotskov
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia
| | | | | | - Aleksey Y Malyshev
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow 117485, Russia
| | - Ivan V Smirnov
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow 117485, Russia.,Medico-Biological Faculty, N.I. Pirogov Russian National Research Medical University, Moscow 117997, Russia
| | - Asya M Azieva
- National Research Center "Kurchatov Institute", Moscow 123182, Russia
| | - Ilya S Sokolov
- National Research Center "Kurchatov Institute", Moscow 123182, Russia
| | - Kiryl D Piatkevich
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mikhail S Burtsev
- National Research Center "Kurchatov Institute", Moscow 123182, Russia
| | - Anna M Varizhuk
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia.,Engelhardt Institute of Molecular Biology RAS, Moscow 119991, Russia
| | - Galina E Pozmogova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia
| | - Konstantin V Anokhin
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia.,Department of Systems Neurobiology and Functional Neurochemistry, P.K. Anokhin Institute of Normal Physiology of RAMS, Moscow 125009, Russia.,National Research Center "Kurchatov Institute", Moscow 123182, Russia
| | - Fedor V Subach
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia
| | - Grigori N Enikolopov
- NBICS Department, Moscow Institute of Physics and Technology, Moscow 123182, Russia.,Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.,Department of Anesthesiology, Stony Brook University Medical Center, NY 11794, USA.,Center for Developmental Genetics, Stony Brook University, NY 11794, USA
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210
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Okada T, Takahashi S, Ishida A, Ishigame H. In vivo multiphoton imaging of immune cell dynamics. Pflugers Arch 2016; 468:1793-1801. [PMID: 27659161 PMCID: PMC5138265 DOI: 10.1007/s00424-016-1882-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 09/07/2016] [Accepted: 09/12/2016] [Indexed: 12/20/2022]
Abstract
Multiphoton imaging has been utilized to analyze in vivo immune cell dynamics over the last 15 years. Particularly, it has deepened the understanding of how immune responses are organized by immune cell migration and interactions. In this review, we first describe the following technical advances in recent imaging studies that contributed to the new findings on the regulation of immune responses and inflammation. Improved multicolor imaging of immune cell behavior has revealed that their interactions are spatiotemporally coordinated to achieve efficient and long-term immunity. The use of photoactivatable and photoconvertible fluorescent proteins has increased duration and volume of cell tracking, even enabling the analysis of inter-organ migration of immune cells. In addition, visualization of immune cell activation using biosensors for intracellular calcium concentration and signaling molecule activities has started to give further mechanistic insights. Then, we also introduce recent imaging analyses of interactions between immune cells and non-immune cells including endothelial, fibroblastic, epithelial, and nerve cells. It is argued that future imaging studies that apply updated technical advances to analyze interactions between immune cells and non-immune cells will be important for thorough physiological understanding of the immune system.
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Affiliation(s)
- Takaharu Okada
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, 230-0045, Japan.
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, 230-0045, Japan.
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012, Japan.
| | - Sonoko Takahashi
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, 230-0045, Japan
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, 230-0045, Japan
| | - Azusa Ishida
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, 230-0045, Japan
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, 230-0045, Japan
| | - Harumichi Ishigame
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, 230-0045, Japan
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211
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Kawakami N. In vivo imaging in autoimmune diseases in the central nervous system. Allergol Int 2016; 65:235-42. [PMID: 26935215 DOI: 10.1016/j.alit.2016.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 11/18/2022] Open
Abstract
Intravital imaging is becoming more popular and is being used to visualize cellular motility and functions. In contrast to in vitro analysis, which resembles in vivo analysis, intravital imaging can be used to observe and analyze cells directly in vivo. In this review, I will summarize recent imaging studies of autoreactive T cell infiltration into the central nervous system (CNS) and provide technical background. During their in vivo journey, autoreactive T cells interact with many different cells. At first, autoreactive T cells interact with endothelial cells in the airways of the lung or with splenocytes, where they acquire a migratory phenotype to infiltrate into the CNS. After arriving at the CNS, they interact with endothelial cells of the leptomeningeal vessels or the choroid plexus before passing through the blood-brain barrier. CNS-infiltrating T cells become activated by recognizing endogenous autoantigens presented by local antigen-presenting cells (APCs). This activation was visualized in vivo by using protein-based sensors. One such sensor detects changes in intracellular calcium concentration as an early marker of T cell activation. Another sensor detects translocation of Nuclear factor of activated T-cells (NFAT) from cytosol to nucleus as a definitive sign of T cell activation. Importantly, intravital imaging is not just used to visualize cellular behavior. Together with precise analysis, intravital imaging deepens our knowledge of cellular functions in living organs and also provides a platform for developing therapeutic treatments.
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Affiliation(s)
- Naoto Kawakami
- Institute of Clinical Neuroimmunology, Biomedical Center and University Hospital, Ludwig-Maximilians Universitaet Muenchen, Munich, Germany; Neuroimmunology Group, Max-Planck Institute of Neurobiology, Martinsried, Germany.
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212
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Ruckh TT, Skipwith CG, Chang W, Bulovic V, Anikeeva P, Clark HA. Ion-Switchable Quantum Dot Förster Resonance Energy Transfer Rates in Ratiometric Potassium Sensors. ACS NANO 2016; 10:4020-30. [PMID: 27089024 PMCID: PMC5270641 DOI: 10.1021/acsnano.5b05396] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The tools for optically imaging cellular potassium concentrations in real-time are currently limited to a small set of molecular indicator dyes. Quantum dot-based nanosensors are more photostable and tunable than organic indicators, but previous designs have fallen short in size, sensitivity, and selectivity. Here, we introduce a small, sensitive, and selective nanosensor for potassium measurements. A dynamic quencher modulates the fluorescence emitted by two different quantum dot species to produce a ratiometric signal. We characterized the potassium-modulated sensor properties and investigated the photonic interactions within the sensors. The quencher's protonation changes in response to potassium, which modulates its Förster radiative energy transfer rate and the corresponding interaction radii with each quantum dot species. The nanosensors respond to changes in potassium concentrations typical of the cellular environment and thus provide a promising tool for imaging potassium fluxes during biological events.
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Affiliation(s)
- Timothy T. Ruckh
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Ave, Boston, MA 02115
| | - Christopher G. Skipwith
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Ave, Boston, MA 02115
| | - Wendi Chang
- Department of Electrical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139
| | - Vladimir Bulovic
- Department of Electrical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139
| | - Polina Anikeeva
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139
| | - Heather A. Clark
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Ave, Boston, MA 02115
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213
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Uslu VV, Grossmann G. The biosensor toolbox for plant developmental biology. CURRENT OPINION IN PLANT BIOLOGY 2016; 29:138-47. [PMID: 26802805 DOI: 10.1016/j.pbi.2015.12.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/01/2015] [Accepted: 12/02/2015] [Indexed: 05/14/2023]
Abstract
Plant development is highly interconnected with the metabolic state of tissues and cells. Current research efforts focus on the identification of the links and mechanisms that govern the interplay between metabolic and gene-regulatory networks. Genetically encoded sensors that allow detection of small molecules in vivo and at high spatio-temporal resolution promise to be the tools of choice for quantifying and visualizing the dynamics of metabolite flux in plants. We provide an overview about current approaches to measure signaling molecules, such as hormones, calcium and sugars, as well as for monitoring the metabolic state via energy equivalents and pH. Biosensors show great potential to address questions of plant development but there are also limitations where alternative approaches are needed.
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Affiliation(s)
- Veli V Uslu
- Ruprecht-Karls-Universität Heidelberg, Department of Plant Molecular Biology, Centre for Organismal Studies, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Guido Grossmann
- Ruprecht-Karls-Universität Heidelberg, CellNetworks Excellence Cluster and Centre for Organismal Studies, Im Neuenheimer Feld 329, 69120 Heidelberg, Germany.
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214
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Gopal S, Couchman J, Pocock R. Redefining the role of syndecans in C. elegans biology. WORM 2016; 5:e1142042. [PMID: 27073736 DOI: 10.1080/21624054.2016.1142042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/08/2016] [Indexed: 12/21/2022]
Abstract
Cytosolic calcium is an important factor during fertilization, development and differentiation. Hence, the control of cytosolic calcium levels has been studied extensively for several decades. Numerous calcium channels have been identified and their mechanism of action elucidated. However, the mode of calcium channel regulation remains elusive. Here we discuss our recent findings regarding the role of syndecans in the regulation of cytosolic calcium levels. Syndecans are transmembrane proteoglycans present in both vertebrates and invertebrates that interact with extracellular ligands resulting in the activation of several downstream signaling pathways. We identified a previously unappreciated role of syndecans in cytosolic calcium regulation in mammals that is conserved in C. elegans. We concluded that calcium regulation is the basic, evolutionarily conserved role for syndecans, which enables them to be integral for multiple cellular functions.
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Affiliation(s)
- Sandeep Gopal
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University , Melbourne, Victoria, Australia
| | - John Couchman
- Department of Biomedical Sciences, University of Copenhagen , Copenhagen, Denmark
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University , Melbourne, Victoria, Australia
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215
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Abstract
UNLABELLED There have been two recent revolutionary advances in neuroscience: First, genetically encoded activity sensors have brought the goal of optical detection of single action potentials in vivo within reach. Second, optogenetic actuators now allow the activity of neurons to be controlled with millisecond precision. These revolutions have now been combined, together with advanced microscopies, to allow "all-optical" readout and manipulation of activity in neural circuits with single-spike and single-neuron precision. This is a transformational advance that will open new frontiers in neuroscience research. Harnessing the power of light in the all-optical approach requires coexpression of genetically encoded activity sensors and optogenetic probes in the same neurons, as well as the ability to simultaneously target and record the light from the selected neurons. It has recently become possible to combine sensors and optical strategies that are sufficiently sensitive and cross talk free to enable single-action-potential sensitivity and precision for both readout and manipulation in the intact brain. The combination of simultaneous readout and manipulation from the same genetically defined cells will enable a wide range of new experiments as well as inspire new technologies for interacting with the brain. The advances described in this review herald a future where the traditional tools used for generations by physiologists to study and interact with the brain-stimulation and recording electrodes-can largely be replaced by light. We outline potential future developments in this field and discuss how the all-optical strategy can be applied to solve fundamental problems in neuroscience. SIGNIFICANCE STATEMENT This review describes the nexus of dramatic recent developments in optogenetic probes, genetically encoded activity sensors, and novel microscopies, which together allow the activity of neural circuits to be recorded and manipulated entirely using light. The optical and protein engineering strategies that form the basis of this "all-optical" approach are now sufficiently advanced to enable single-neuron and single-action potential precision for simultaneous readout and manipulation from the same functionally defined neurons in the intact brain. These advances promise to illuminate many fundamental challenges in neuroscience, including transforming our search for the neural code and the links between neural circuit activity and behavior.
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216
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Le Borgne M, Raju S, Zinselmeyer BH, Le VT, Li J, Wang Y, Miller MJ, Shaw AS. Real-Time Analysis of Calcium Signals during the Early Phase of T Cell Activation Using a Genetically Encoded Calcium Biosensor. THE JOURNAL OF IMMUNOLOGY 2016; 196:1471-9. [PMID: 26746192 DOI: 10.4049/jimmunol.1502414] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/10/2015] [Indexed: 02/07/2023]
Abstract
Proper T cell activation is promoted by sustained calcium signaling downstream of the TCR. However, the dynamics of calcium flux after stimulation with an APC in vivo remain to be fully understood. Previous studies focusing on T cell motility suggested that the activation of naive T cells in the lymph node occurs in distinct phases. In phase I, T cells make multiple transient contacts with dendritic cells before entering a phase II, where they exist in stable clusters with dendritic cells. It has been suggested that T cells signal during transient contacts of phase I, but this has never been shown directly. Because time-dependent loss of calcium dyes from cells hampers long-term imaging of cells in vivo after antigenic stimulation, we generated a knock-in mouse expressing a modified form of the Cameleon fluorescence resonance energy transfer reporter for intracellular calcium and examined calcium flux both in vitro and in situ. In vitro, we observed transient, oscillatory, and sustained calcium flux after contact with APC, but these behaviors were not affected by the type of APC or Ag quantity, but were, however, moderately dependent on Ag quality. In vivo, we found that during phase I, T cells exhibit weak calcium fluxes and detectable changes in cell motility. This demonstrates that naive T cells signal during phase I and support the hypothesis that accumulated calcium signals are required to signal the beginning of phase II.
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Affiliation(s)
- Marie Le Borgne
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110; Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO 63110
| | - Saravanan Raju
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Bernd H Zinselmeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Viet T Le
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - JiaJia Li
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Yingxiao Wang
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093; and
| | - Mark J Miller
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Andrey S Shaw
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110; Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO 63110;
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217
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MacRenaris KW, Ma Z, Krueger RL, Carney CE, Meade TJ. Cell-Permeable Esterase-Activated Ca(II)-Sensitive MRI Contrast Agent. Bioconjug Chem 2016; 27:465-73. [PMID: 26689452 DOI: 10.1021/acs.bioconjchem.5b00561] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calcium [Ca(II)] is a fundamental transducer of electrical activity in the central nervous system (CNS). Influx of Ca(II) into the cytosol is responsible for action potential initiation and propagation, and initiates interneuronal communication via release of neurotransmitters and activation of gene expression. Despite the importance of Ca(II) in physiology, it remains a challenge to visualize Ca(II) flux in the central nervous system (CNS) in vivo. To address these challenges, we have developed a new generation, Ca(II)-activated MRI contrast agent that utilizes ethyl esters to increase cell labeling and prevent extracellular divalent Ca(II) binding. Following labeling, the ethyl esters can be cleaved, thus allowing the agent to bind Ca(II), increasing relaxivity and resulting in enhanced positive MR image contrast. The ability of this probe to discriminate between extra- and intracellular Ca(II) may allow for spatiotemporal in vivo imaging of Ca(II) flux during seizures or ischemia where large Ca(II) fluxes (1-10 μM) can result in cell death.
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Affiliation(s)
- Keith W MacRenaris
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Zhidong Ma
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Ruby L Krueger
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Christiane E Carney
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
| | - Thomas J Meade
- Departments of Chemistry, Molecular Biosciences, Neurobiology, Biomedical Engineering, and Radiology, Northwestern University , Evanston, Illinois 60208 , United States
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218
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Gheghiani L, Gavet O. Spatiotemporal Investigation of Phosphorylation Events During Cell Cycle Progression. Methods Mol Biol 2016; 1342:157-71. [PMID: 26254922 DOI: 10.1007/978-1-4939-2957-3_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Polo-like kinase 1 (Plk1) is an essential kinase for mitotic commitment and progression through mitosis. In contrast to its well characterized roles during mitosis, the precise molecular events controlled by Plk1 during G2/M progression and their spatiotemporal regulation are still poorly elucidated. We recently investigated Plk1-dependent regulation of Cdc25C phosphatase, an activator of the master mitotic driver Cyclin B1-Cdk1. To this end, we generated a genetically encoded FRET (Förster Resonance Energy Transfer)-based Cdc25C phosphorylation biosensor to observe Cdc25 spatiotemporal phosphorylation during cell cycle progression in live single cell assays. Because this approach proved to be powerful, we provide here guidelines for the development of biosensors for any phosphorylation site of interest.
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Affiliation(s)
- Lilia Gheghiani
- Sorbonne Universités, UPMC Paris VI, UFR927, 75005, Paris, France
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219
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Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans. Proc Natl Acad Sci U S A 2015; 113:E1074-81. [PMID: 26712014 DOI: 10.1073/pnas.1507110112] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. We present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. This instrument provides whole-brain imaging with cellular resolution in an unrestrained and behaving animal. We use spinning-disk confocal microscopy to capture 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s at 6 head-volumes/s. A suite of three cameras monitor neuronal fluorescence and the animal's position and orientation. Custom software tracks the 3D position of the animal's head in real time and two feedback loops adjust a motorized stage and objective to keep the animal's head within the field of view as the animal roams freely. We observe calcium transients from up to 77 neurons for over 4 min and correlate this activity with the animal's behavior. We characterize noise in the system due to animal motion and show that, across worms, multiple neurons show significant correlations with modes of behavior corresponding to forward, backward, and turning locomotion.
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220
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Maysinger D, Ji J, Hutter E, Cooper E. Nanoparticle-Based and Bioengineered Probes and Sensors to Detect Physiological and Pathological Biomarkers in Neural Cells. Front Neurosci 2015; 9:480. [PMID: 26733793 PMCID: PMC4683200 DOI: 10.3389/fnins.2015.00480] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/30/2015] [Indexed: 01/11/2023] Open
Abstract
Nanotechnology, a rapidly evolving field, provides simple and practical tools to investigate the nervous system in health and disease. Among these tools are nanoparticle-based probes and sensors that detect biochemical and physiological properties of neurons and glia, and generate signals proportionate to physical, chemical, and/or electrical changes in these cells. In this context, quantum dots (QDs), carbon-based structures (C-dots, grapheme, and nanodiamonds) and gold nanoparticles are the most commonly used nanostructures. They can detect and measure enzymatic activities of proteases (metalloproteinases, caspases), ions, metabolites, and other biomolecules under physiological or pathological conditions in neural cells. Here, we provide some examples of nanoparticle-based and genetically engineered probes and sensors that are used to reveal changes in protease activities and calcium ion concentrations. Although significant progress in developing these tools has been made for probing neural cells, several challenges remain. We review many common hurdles in sensor development, while highlighting certain advances. In the end, we propose some future directions and ideas for developing practical tools for neural cell investigations, based on the maxim "Measure what is measurable, and make measurable what is not so" (Galileo Galilei).
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Affiliation(s)
- Dusica Maysinger
- Department of Pharmacology and Therapeutics, McGill University Montreal, QC, Canada
| | - Jeff Ji
- Department of Pharmacology and Therapeutics, McGill University Montreal, QC, Canada
| | - Eliza Hutter
- Department of Pharmacology and Therapeutics, McGill University Montreal, QC, Canada
| | - Elis Cooper
- Department of Physiology, McGill University Montreal, QC, Canada
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221
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Fabritius A, Griesbeck O. Design and directed evolution of genetically encoded cGMP sensors. BMC Pharmacol Toxicol 2015. [PMCID: PMC4565077 DOI: 10.1186/2050-6511-16-s1-a48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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222
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Osswald M, Jung E, Sahm F, Solecki G, Venkataramani V, Blaes J, Weil S, Horstmann H, Wiestler B, Syed M, Huang L, Ratliff M, Karimian Jazi K, Kurz FT, Schmenger T, Lemke D, Gömmel M, Pauli M, Liao Y, Häring P, Pusch S, Herl V, Steinhäuser C, Krunic D, Jarahian M, Miletic H, Berghoff AS, Griesbeck O, Kalamakis G, Garaschuk O, Preusser M, Weiss S, Liu H, Heiland S, Platten M, Huber PE, Kuner T, von Deimling A, Wick W, Winkler F. Brain tumour cells interconnect to a functional and resistant network. Nature 2015; 528:93-8. [PMID: 26536111 DOI: 10.1038/nature16071] [Citation(s) in RCA: 680] [Impact Index Per Article: 75.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 10/09/2015] [Indexed: 12/23/2022]
Abstract
Astrocytic brain tumours, including glioblastomas, are incurable neoplasms characterized by diffusely infiltrative growth. Here we show that many tumour cells in astrocytomas extend ultra-long membrane protrusions, and use these distinct tumour microtubes as routes for brain invasion, proliferation, and to interconnect over long distances. The resulting network allows multicellular communication through microtube-associated gap junctions. When damage to the network occurred, tumour microtubes were used for repair. Moreover, the microtube-connected astrocytoma cells, but not those remaining unconnected throughout tumour progression, were protected from cell death inflicted by radiotherapy. The neuronal growth-associated protein 43 was important for microtube formation and function, and drove microtube-dependent tumour cell invasion, proliferation, interconnection, and radioresistance. Oligodendroglial brain tumours were deficient in this mechanism. In summary, astrocytomas can develop functional multicellular network structures. Disconnection of astrocytoma cells by targeting their tumour microtubes emerges as a new principle to reduce the treatment resistance of this disease.
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Affiliation(s)
- Matthias Osswald
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Erik Jung
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Felix Sahm
- Department of Neuropathology, Institute of Pathology, Ruprecht-Karls University Heidelberg, INF 224, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neuropathology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), INF 224, 69120 Heidelberg, Germany
| | - Gergely Solecki
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Varun Venkataramani
- Department of Functional Neuroanatomy, Institute of Anatomy and Cell Biology, Heidelberg University, INF 307, 69120 Heidelberg, Germany
| | - Jonas Blaes
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Sophie Weil
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Heinz Horstmann
- Department of Functional Neuroanatomy, Institute of Anatomy and Cell Biology, Heidelberg University, INF 307, 69120 Heidelberg, Germany
| | - Benedikt Wiestler
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.,Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar der Technischen Universität München, 81675 Munich, Germany
| | - Mustafa Syed
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Lulu Huang
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Miriam Ratliff
- Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.,Neurosurgery Clinic, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany
| | - Kianush Karimian Jazi
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Felix T Kurz
- Department of Neuroradiology, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany
| | - Torsten Schmenger
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Dieter Lemke
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Miriam Gömmel
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Martin Pauli
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | - Yunxiang Liao
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Peter Häring
- Department of Medical Physics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Stefan Pusch
- Department of Neuropathology, Institute of Pathology, Ruprecht-Karls University Heidelberg, INF 224, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neuropathology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), INF 224, 69120 Heidelberg, Germany
| | - Verena Herl
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | - Damir Krunic
- Light Microscopy Facility, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Mostafa Jarahian
- Department of Translational Immunology, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Hrvoje Miletic
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Anna S Berghoff
- Institute of Neurology, Medical University of Vienna, Vienna, Austria; Comprehensive Cancer Center, CNS Unit, Medical University of Vienna, 1090 Vienna, Austria
| | - Oliver Griesbeck
- Tools For Bio-Imaging, Max-Planck-Institute of Neurobiology, 82152 Martinsried, Germany
| | - Georgios Kalamakis
- Institute of Physiology II, Eberhard Karls University of Tübingen, 72074 Tübingen, Germany
| | - Olga Garaschuk
- Institute of Physiology II, Eberhard Karls University of Tübingen, 72074 Tübingen, Germany
| | - Matthias Preusser
- Department of Medicine I, Medical University of Vienna, Vienna, Austria; Comprehensive Cancer Center, CNS Unit, Medical University of Vienna, 1090 Vienna, Austria
| | - Samuel Weiss
- Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Department of Cell Biology and Anatomy, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,Clark Smith Brain Tumor Research Centre, Southern Alberta Cancer Research Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Haikun Liu
- Helmholtz Young Investigator Group, Normal and Neoplastic CNS Stem Cells, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), INF 280, 69120 Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany
| | - Michael Platten
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Peter E Huber
- CCU Molecular and Radiation Oncology, German Cancer Research Center (DKFZ), INF 280, 69120 Heidelberg, Germany.,Department of Radiation Oncology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute of Anatomy and Cell Biology, Heidelberg University, INF 307, 69120 Heidelberg, Germany
| | - Andreas von Deimling
- Department of Neuropathology, Institute of Pathology, Ruprecht-Karls University Heidelberg, INF 224, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neuropathology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), INF 224, 69120 Heidelberg, Germany
| | - Wolfgang Wick
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Frank Winkler
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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223
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Lindquist R, Niesner R. Intravital FRET: comprehending life at single-molecule level. Focus on "A practical method for monitoring FRET-based biosensors in living animals using two-photon microscopy". Am J Physiol Cell Physiol 2015; 309:C722-3. [PMID: 26468210 DOI: 10.1152/ajpcell.00286.2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Raluca Niesner
- Deutsches Rheuma-Forschungszentrum (DRFZ), Berlin, Germany
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224
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Gopal S, Søgaard P, Multhaupt HAB, Pataki C, Okina E, Xian X, Pedersen ME, Stevens T, Griesbeck O, Park PW, Pocock R, Couchman JR. Transmembrane proteoglycans control stretch-activated channels to set cytosolic calcium levels. J Cell Biol 2015; 210:1199-211. [PMID: 26391658 PMCID: PMC4586746 DOI: 10.1083/jcb.201501060] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 08/25/2015] [Indexed: 02/07/2023] Open
Abstract
Syndecans regulate members of the transient receptor potential family to control cytosolic calcium levels with impact on cell adhesion, junction formation, and neuronal guidance. Transmembrane heparan sulfate proteoglycans regulate multiple aspects of cell behavior, but the molecular basis of their signaling is unresolved. The major family of transmembrane proteoglycans is the syndecans, present in virtually all nucleated cells, but with mostly unknown functions. Here, we show that syndecans regulate transient receptor potential canonical (TRPCs) channels to control cytosolic calcium equilibria and consequent cell behavior. In fibroblasts, ligand interactions with heparan sulfate of syndecan-4 recruit cytoplasmic protein kinase C to target serine714 of TRPC7 with subsequent control of the cytoskeleton and the myofibroblast phenotype. In epidermal keratinocytes a syndecan–TRPC4 complex controls adhesion, adherens junction composition, and early differentiation in vivo and in vitro. In Caenorhabditis elegans, the TRPC orthologues TRP-1 and -2 genetically complement the loss of syndecan by suppressing neuronal guidance and locomotory defects related to increases in neuronal calcium levels. The widespread and conserved syndecan–TRPC axis therefore fine tunes cytoskeletal organization and cell behavior.
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Affiliation(s)
- Sandeep Gopal
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Pernille Søgaard
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Hinke A B Multhaupt
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Csilla Pataki
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Elena Okina
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Xiaojie Xian
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Mikael E Pedersen
- Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Troy Stevens
- Department of Pharmacology, Center for Lung Biology, University of South Alabama, Mobile, AL 36688 Department of Medicine, Center for Lung Biology, University of South Alabama, Mobile, AL 36688
| | - Oliver Griesbeck
- Max Planck Institute of Neurobiology, 82152 Martinsried, Germany
| | - Pyong Woo Park
- Division of Newborn Medicine, Children's Hospital, Harvard Medical School, Boston, MA 02115 Division of Respiratory Diseases, Children's Hospital, Harvard Medical School, Boston, MA 02115
| | - Roger Pocock
- Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
| | - John R Couchman
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark Biotech Research and Innovation Center, University of Copenhagen, 2200 Copenhagen, Denmark
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225
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Søndergaard RV, Christensen NM, Henriksen JR, Kumar EKP, Almdal K, Andresen TL. Facing the Design Challenges of Particle-Based Nanosensors for Metabolite Quantification in Living Cells. Chem Rev 2015; 115:8344-78. [PMID: 26244372 DOI: 10.1021/cr400636x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Rikke V Søndergaard
- Department of Micro- and Nanotechnology, Technical University of Denmark , Produktionstorvet 423, 2800 Lyngby, Denmark
| | - Nynne M Christensen
- Department of Micro- and Nanotechnology, Technical University of Denmark , Produktionstorvet 423, 2800 Lyngby, Denmark
| | - Jonas R Henriksen
- Department of Micro- and Nanotechnology, Technical University of Denmark , Produktionstorvet 423, 2800 Lyngby, Denmark
| | - E K Pramod Kumar
- Department of Micro- and Nanotechnology, Technical University of Denmark , Produktionstorvet 423, 2800 Lyngby, Denmark
| | - Kristoffer Almdal
- Department of Micro- and Nanotechnology, Technical University of Denmark , Produktionstorvet 423, 2800 Lyngby, Denmark
| | - Thomas L Andresen
- Department of Micro- and Nanotechnology, Technical University of Denmark , Produktionstorvet 423, 2800 Lyngby, Denmark
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226
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Wang Y, Meng Y, Wang S, Li C, Shi W, Chen J, Wang J, Huang R. Direct Solvent-Derived Polymer-Coated Nitrogen-Doped Carbon Nanodots with High Water Solubility for Targeted Fluorescence Imaging of Glioma. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:3575-3581. [PMID: 25808813 DOI: 10.1002/smll.201403718] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/18/2015] [Indexed: 06/04/2023]
Abstract
Cancer imaging requires biocompatible and bright contrast-agents with selective and high accumulation in the tumor region but low uptake in normal tissues. Herein, 1-methyl-2-pyrrolidinone (NMP)-derived polymer-coated nitrogen-doped carbon nanodots (pN-CNDs) with a particle size in the range of 5-15 nm are prepared by a facile direct solvothermal reaction. The as-prepared pN-CNDs exhibit stable and adjustable fluorescence and excellent water solubility. Results of a cell viability test (CCK-8) and histology analysis both demonstrate that the pN-CNDs have no obvious cytotoxicity. Most importantly, the pN-CNDs can expediently enter glioma cells in vitro and also mediate glioma fluorescence imaging in vivo with good contrast via elevated passive targeting.
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Affiliation(s)
- Yi Wang
- Center of Analysis and Measurement, Fudan University, Shanghai, 200433, China
| | - Ying Meng
- Department of Pharmaceutics, School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education, Fudan University, Shanghai, 201203, China
| | - Shanshan Wang
- Department of Pharmaceutics, School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education, Fudan University, Shanghai, 201203, China
| | - Chengyi Li
- Department of Pharmaceutics, School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education, Fudan University, Shanghai, 201203, China
| | - Wei Shi
- Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Jian Chen
- Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Jianxin Wang
- Department of Pharmaceutics, School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education, Fudan University, Shanghai, 201203, China
| | - Rongqin Huang
- Department of Pharmaceutics, School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education, Fudan University, Shanghai, 201203, China
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227
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Keinath NF, Waadt R, Brugman R, Schroeder JI, Grossmann G, Schumacher K, Krebs M. Live Cell Imaging with R-GECO1 Sheds Light on flg22- and Chitin-Induced Transient [Ca(2+)]cyt Patterns in Arabidopsis. MOLECULAR PLANT 2015; 8:1188-200. [PMID: 26002145 PMCID: PMC5134422 DOI: 10.1016/j.molp.2015.05.006] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 05/03/2015] [Accepted: 05/05/2015] [Indexed: 05/17/2023]
Abstract
Intracellular Ca(2+) transients are an integral part of the signaling cascade during pathogen-associated molecular pattern (PAMP)-triggered immunity in plants. Yet, our knowledge about the spatial distribution of PAMP-induced Ca(2+) signals is limited. Investigation of cell- and tissue-specific properties of Ca(2+)-dependent signaling processes requires versatile Ca(2+) reporters that are able to extract spatial information from cellular and subcellular structures, as well as from whole tissues over time periods from seconds to hours. Fluorescence-based reporters cover both a broad spatial and temporal range, which makes them ideally suited to study Ca(2+) signaling in living cells. In this study, we compared two fluorescence-based Ca(2+) sensors: the Förster resonance energy transfer (FRET)-based reporter yellow cameleon NES-YC3.6 and the intensity-based sensor R-GECO1. We demonstrate that R-GECO1 exhibits a significantly increased signal change compared with ratiometric NES-YC3.6 in response to several stimuli. Due to its superior sensitivity, R-GECO1 is able to report flg22- and chitin-induced Ca(2+) signals on a cellular scale, which allowed identification of defined [Ca(2+)]cyt oscillations in epidermal and guard cells in response to the fungal elicitor chitin. Moreover, we discovered that flg22- and chitin-induced Ca(2+) signals in the root initiate from the elongation zone.
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Affiliation(s)
- Nana F Keinath
- Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Rainer Waadt
- Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany; Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, 92093 La Jolla, USA
| | - Rik Brugman
- Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Julian I Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, 92093 La Jolla, USA
| | - Guido Grossmann
- Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Karin Schumacher
- Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Melanie Krebs
- Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.
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228
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Berlin S, Carroll EC, Newman ZL, Okada HO, Quinn CM, Kallman B, Rockwell NC, Martin SS, Lagarias JC, Isacoff EY. Photoactivatable genetically encoded calcium indicators for targeted neuronal imaging. Nat Methods 2015; 12:852-8. [PMID: 26167640 PMCID: PMC4597790 DOI: 10.1038/nmeth.3480] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/01/2015] [Indexed: 12/11/2022]
Abstract
Circuit mapping requires knowledge of both structural and functional connectivity between cells. Although optical tools have been made to assess either the morphology and projections of neurons or their activity and functional connections, few probes integrate this information. We have generated a family of photoactivatable genetically encoded Ca(2+) indicators that combines attributes of high-contrast photolabeling with high-sensitivity Ca(2+) detection in a single-color protein sensor. We demonstrated in cultured neurons and in fruit fly and zebrafish larvae how single cells could be selected out of dense populations for visualization of morphology and high signal-to-noise measurements of activity, synaptic transmission and connectivity. Our design strategy is transferrable to other sensors based on circularly permutated GFP (cpGFP).
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Affiliation(s)
- Shai Berlin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA
| | - Elizabeth C Carroll
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Zachary L Newman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Hitomi O Okada
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Carson M Quinn
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Benjamin Kallman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA
| | - Nathan C Rockwell
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
| | - Shelley S Martin
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
| | - J Clark Lagarias
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
| | - Ehud Y Isacoff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA.,Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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229
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Dufour S, De Koninck Y. Optrodes for combined optogenetics and electrophysiology in live animals. NEUROPHOTONICS 2015; 2:031205. [PMID: 26158014 PMCID: PMC4489589 DOI: 10.1117/1.nph.2.3.031205] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 05/19/2015] [Indexed: 05/15/2023]
Abstract
Optical tissue properties limit visible light depth penetration in tissue. Because of this, the recent development of optogenetic tools was quickly followed by the development of light delivery devices for in vivo optogenetics applications. We summarize the efforts made in the last decade to design neural probes that combine conventional electrophysiological recordings and optical channel(s) for optogenetic activation, often referred to as optodes or optrodes. Several aspects including challenges for light delivery in living brain tissue, the combination of light delivery with electrophysiological recordings, probe designs, multimodality, wireless implantable system, and practical considerations guiding the choice of configuration depending on the questions one seeks to address are presented.
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Affiliation(s)
- Suzie Dufour
- Toronto Western Research Institute, Fundamental Neurobiology, 60 Leonard Avenue, Toronto M5T 2S8, Canada
- University of Toronto, Institute of Biomaterials and Biomedical Engineering, 164 College Street, Toronto M5S 3G9, Canada
| | - Yves De Koninck
- Institut Universitaire en Santé Mentale de Québec, 2601 chemin de la Canardière, Québec G1J 2G3, Canada
- Université Laval, Department of Psychiatry and Neuroscience, 1050 Avenue de la médecine, Québec G1V0A6, Canada
- Université Laval, Centre d’Optique, Photonique et Laser, 2375 rue de la Terrasse, Québec G1V 0A6, Canada
- Address all correspondence to: Yves De Koninck, E-mail:
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230
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Abstract
Advances in optical manipulation and observation of neural activity have set the stage for widespread implementation of closed-loop and activity-guided optical control of neural circuit dynamics. Closing the loop optogenetically (i.e., basing optogenetic stimulation on simultaneously observed dynamics in a principled way) is a powerful strategy for causal investigation of neural circuitry. In particular, observing and feeding back the effects of circuit interventions on physiologically relevant timescales is valuable for directly testing whether inferred models of dynamics, connectivity, and causation are accurate in vivo. Here we highlight technical and theoretical foundations as well as recent advances and opportunities in this area, and we review in detail the known caveats and limitations of optogenetic experimentation in the context of addressing these challenges with closed-loop optogenetic control in behaving animals.
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Affiliation(s)
- Logan Grosenick
- Department of Bioengineering, Stanford University, Stanford, CA 94305 USA; CNC Program, Stanford University, Stanford, CA 94305 USA; Neurosciences Program, Stanford University, Stanford, CA 94305 USA
| | - James H Marshel
- Department of Bioengineering, Stanford University, Stanford, CA 94305 USA; CNC Program, Stanford University, Stanford, CA 94305 USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA 94305 USA; CNC Program, Stanford University, Stanford, CA 94305 USA; Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305 USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305 USA.
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231
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Abstract
Stem cell-based therapies hold considerable promise for many currently devastating neurological disorders. Substantial progress has been made in the derivation of disease-relevant human donor cell populations. Behavioral data in relevant animal models of disease have demonstrated therapeutic efficacy for several cell-based approaches. Consequently, cGMP grade cell products are currently being developed for first in human clinical trials in select disorders. Despite the therapeutic promise, the presumed mechanism of action of donor cell populations often remains insufficiently validated. It depends greatly on the properties of the transplanted cell type and the underlying host pathology. Several new technologies have become available to probe mechanisms of action in real time and to manipulate in vivo cell function and integration to enhance therapeutic efficacy. Results from such studies generate crucial insight into the nature of brain repair that can be achieved today and push the boundaries of what may be possible in the future.
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232
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Large Scale Bacterial Colony Screening of Diversified FRET Biosensors. PLoS One 2015; 10:e0119860. [PMID: 26061878 PMCID: PMC4464885 DOI: 10.1371/journal.pone.0119860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/16/2015] [Indexed: 11/30/2022] Open
Abstract
Biosensors based on Förster Resonance Energy Transfer (FRET) between fluorescent protein mutants have started to revolutionize physiology and biochemistry. However, many types of FRET biosensors show relatively small FRET changes, making measurements with these probes challenging when used under sub-optimal experimental conditions. Thus, a major effort in the field currently lies in designing new optimization strategies for these types of sensors. Here we describe procedures for optimizing FRET changes by large scale screening of mutant biosensor libraries in bacterial colonies. We describe optimization of biosensor expression, permeabilization of bacteria, software tools for analysis, and screening conditions. The procedures reported here may help in improving FRET changes in multiple suitable classes of biosensors.
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233
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Radbruch H, Bremer D, Mothes R, Günther R, Rinnenthal JL, Pohlan J, Ulbricht C, Hauser AE, Niesner R. Intravital FRET: Probing Cellular and Tissue Function in Vivo. Int J Mol Sci 2015; 16:11713-27. [PMID: 26006244 PMCID: PMC4463726 DOI: 10.3390/ijms160511713] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/13/2015] [Indexed: 12/02/2022] Open
Abstract
The development of intravital Förster Resonance Energy Transfer (FRET) is required to probe cellular and tissue function in the natural context: the living organism. Only in this way can biomedicine truly comprehend pathogenesis and develop effective therapeutic strategies. Here we demonstrate and discuss the advantages and pitfalls of two strategies to quantify FRET in vivo-ratiometrically and time-resolved by fluorescence lifetime imaging-and show their concrete application in the context of neuroinflammation in adult mice.
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Affiliation(s)
- Helena Radbruch
- Neuropathology, Charité-University of Medicine, Berlin 10117, Germany.
| | - Daniel Bremer
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
| | - Ronja Mothes
- Neuropathology, Charité-University of Medicine, Berlin 10117, Germany.
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
| | - Robert Günther
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
| | | | - Julian Pohlan
- Neuropathology, Charité-University of Medicine, Berlin 10117, Germany.
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
| | - Carolin Ulbricht
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
- Immundynamics and Intravital Microscopy, Charité-University of Medicine, Berlin 10117, Germany.
| | - Anja E Hauser
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
- Immundynamics and Intravital Microscopy, Charité-University of Medicine, Berlin 10117, Germany.
| | - Raluca Niesner
- Germany German Rheumatism Research Center, Berlin 10117, Germany.
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234
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Abstract
The measurement of intracellular analytes has been key in understanding cellular processes and function, and the use of biological nanosensors has revealed the spatial and temporal variation in their concentrations. In particular, ratiometric nanosensors allow quantitative measurements of analyte concentrations. The present review focuses on the recent advances in ratiometric intracellular biological nanosensors, with an emphasis on their utility in measuring analytes that are important in cell function.
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235
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Breckwoldt MO, Wittmann C, Misgeld T, Kerschensteiner M, Grabher C. Redox imaging using genetically encoded redox indicators in zebrafish and mice. Biol Chem 2015; 396:511-22. [DOI: 10.1515/hsz-2014-0294] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/26/2015] [Indexed: 12/28/2022]
Abstract
Abstract
Redox signals have emerged as important regulators of cellular physiology and pathology. The advent of redox imaging in vertebrate systems now provides the opportunity to dynamically visualize redox signaling during development and disease. In this review, we summarize recent advances in the generation of genetically encoded redox indicators (GERIs), introduce new redox imaging strategies, and highlight key publications in the field of vertebrate redox imaging. We also discuss the limitations and future potential of in vivo redox imaging in zebrafish and mice.
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236
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Dugué GP, Tricoire L. [Principles and applications of optogenetics in neuroscience]. Med Sci (Paris) 2015; 31:291-303. [PMID: 25855283 DOI: 10.1051/medsci/20153103015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Numerous achievements in biology have resulted from the evolution of biophotonics, a general term describing the use of light in the study of living systems. Over the last fifteen years, biophotonics has progressively blended with molecular genetics to give rise to optogenetics, a set of techniques enabling the functional study of genetically-defined cellular populations, compartments or processes with optical methods. In neuroscience, optogenetics allows real-time monitoring and control of the activity of specific neuronal populations in a wide range of animal models. This technical breakthrough provides a new level of sophistication in experimental approaches in the field of fundamental neuroscience, significantly enhancing our ability to understand the complexity of neuronal circuits.
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Affiliation(s)
- Guillaume P Dugué
- CNRS UMR 8197, Inserm U1024, IBENS S4.9, 46, rue d'Ulm, 75005 Paris, France
| | - Ludovic Tricoire
- CNRS UMR 8246, Inserm U1130, université Pierre et Marie Curie UM CR119, 9, quai Saint Bernard, 75005 Paris, France
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237
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Siffrin V, Birkenstock J, Luchtman DW, Gollan R, Baumgart J, Niesner RA, Griesbeck O, Zipp F. FRET based ratiometric Ca(2+) imaging to investigate immune-mediated neuronal and axonal damage processes in experimental autoimmune encephalomyelitis. J Neurosci Methods 2015; 249:8-15. [PMID: 25864804 DOI: 10.1016/j.jneumeth.2015.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 04/02/2015] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Irreversible axonal and neuronal damage are the correlate of disability in patients suffering from multiple sclerosis (MS). A sustained increase of cytoplasmic free [Ca(2+)] is a common upstream event of many neuronal and axonal damage processes and could represent an early and potentially reversible step. NEW METHOD We propose a method to specifically analyze the neurodegenerative aspects of experimental autoimmune encephalomyelitis by Förster Resonance Energy Transfer (FRET) imaging of neuronal and axonal Ca(2+) dynamics by two-photon laser scanning microscopy (TPLSM). RESULTS Using the genetically encoded Ca(2+) sensor TN-XXL expressed in neurons and their corresponding axons, we confirm the increase of cytoplasmic free [Ca(2+)] in axons and neurons of autoimmune inflammatory lesions compared to those in non-inflamed brains. We show that these relative [Ca(2+)] increases were associated with immune-neuronal interactions. COMPARISON WITH EXISTING METHODS In contrast to Ca(2+)-sensitive dyes the use of a genetically encoded Ca(2+) sensor allows reliable intraaxonal free [Ca(2+)] measurements in living anesthetized mice in health and disease. This method detects early axonal damage processes in contrast to e.g. cell/axon morphology analysis, that rather detects late signs of neurodegeneration. CONCLUSIONS Thus, we describe a method to analyze and monitor early neuronal damage processes in the brain in vivo.
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Affiliation(s)
- Volker Siffrin
- Neurology Department, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany.
| | - Jérôme Birkenstock
- Neurology Department, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
| | - Dirk W Luchtman
- Neurology Department, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
| | - René Gollan
- Neurology Department, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
| | - Jan Baumgart
- Central Research Animal Facility, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
| | | | - Oliver Griesbeck
- Max Planck Institute of Neurobiology, 82152 Martinsried, Germany
| | - Frauke Zipp
- Neurology Department, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
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238
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Lillis KP, Dulla C, Maheshwari A, Coulter D, Mody I, Heinemann U, Armbruster M, Žiburkus J. WONOEP appraisal: molecular and cellular imaging in epilepsy. Epilepsia 2015; 56:505-13. [PMID: 25779014 PMCID: PMC4397142 DOI: 10.1111/epi.12939] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2015] [Indexed: 01/01/2023]
Abstract
Great advancements have been made in understanding the basic mechanisms of ictogenesis using single-cell electrophysiology (e.g., patch clamp, sharp electrode), large-scale electrophysiology (e.g., electroencephalography [EEG], field potential recording), and large-scale imaging (magnetic resonance imaging [MRI], positron emission tomography [PET], calcium imaging of acetoxymethyl ester [AM] dye-loaded tissue). Until recently, it has been challenging to study experimentally how population rhythms emerge from cellular activity. Newly developed optical imaging technologies hold promise for bridging this gap by making it possible to simultaneously record the many cellular elements that comprise a neural circuit. Furthermore, easily accessible genetic technologies for targeting expression of fluorescent protein-based indicators make it possible to study, in animal models of epilepsy, epileptogenic changes to neural circuits over long periods. In this review, we summarize some of the latest imaging tools (fluorescent probes, gene delivery methods, and microscopy techniques) that can lead to the advancement of cell- and circuit-level understanding of epilepsy, which in turn may inform and improve development of next generation antiepileptic and antiepileptogenic drugs.
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Affiliation(s)
- Kyle P Lillis
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A; Harvard Medical School, Boston, Massachusetts, U.S.A
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239
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Christo SN, Diener KR, Hayball JD. The functional contribution of calcium ion flux heterogeneity in T cells. Immunol Cell Biol 2015; 93:694-704. [PMID: 25823995 DOI: 10.1038/icb.2015.34] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/15/2015] [Accepted: 02/16/2015] [Indexed: 12/30/2022]
Abstract
The role of intracellular calcium ion oscillations in T-cell physiology is being increasingly appreciated by studies that describe how unique temporal and spatial calcium ion signatures can control different signalling pathways. Within this review, we provide detailed mechanisms of calcium ion oscillations, and emphasise the pivotal role that calcium signalling plays in directing crucial events pertaining to T-cell functionality. We also describe methods of calcium ion quantification, and take the opportunity to discuss how a deeper understanding of calcium signalling combined with new detection and quantification methodologies can be used to better design immunotherapies targeting T-cell responses.
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Affiliation(s)
- Susan N Christo
- Experimental Therapeutics Laboratory, Sansom Institute and Hanson Institute, School of Pharmacy and Medical Science, Division of Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Kerrilyn R Diener
- Experimental Therapeutics Laboratory, Sansom Institute and Hanson Institute, School of Pharmacy and Medical Science, Division of Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Robinson Research Institute, School of Paediatrics and Reproductive Health, Faculty of Health Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - John D Hayball
- Experimental Therapeutics Laboratory, Sansom Institute and Hanson Institute, School of Pharmacy and Medical Science, Division of Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, South Australia, Australia
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240
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In vivo odourant response properties of migrating adult-born neurons in the mouse olfactory bulb. Nat Commun 2015; 6:6349. [PMID: 25695931 DOI: 10.1038/ncomms7349] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/21/2015] [Indexed: 12/26/2022] Open
Abstract
Juxtaglomerular neurons (JGNs) of the mammalian olfactory bulb are generated throughout life. Their integration into the preexisting neural network, their differentiation and survival therein depend on sensory activity, but when and how these adult-born cells acquire responsiveness to sensory stimuli remains unknown. In vivo two-photon imaging of retrovirally labelled adult-born JGNs reveals that ~90% of the cells arrive at the glomerular layer after day post injection (DPI) 7. After arrival, adult-born JGNs are still migrating, but at DPI 9, 52% of them have odour-evoked Ca(2+) signals. Their odourant sensitivity closely resembles that of the parent glomerulus and surrounding JGNs, and their spontaneous and odour-evoked spiking is similar to that of their resident neighbours. Our data reveal a remarkably rapid functional integration of adult-born cells into the preexisting neural network. The mature pattern of odour-evoked responses of these cells strongly contrasts with their molecular phenotype, which is typical of immature, migrating neuroblasts.
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241
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Huang S, Wang L, Zhu F, Su W, Sheng J, Huang C, Xiao Q. A ratiometric nanosensor based on fluorescent carbon dots for label-free and highly selective recognition of DNA. RSC Adv 2015. [DOI: 10.1039/c5ra05519a] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A ratiometric nanosensor based on fluorescent carbon dots for label-free and highly selective recognition of DNA.
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Affiliation(s)
- Shan Huang
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
| | - Lumin Wang
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
| | - Fawei Zhu
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
| | - Wei Su
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
| | - Jiarong Sheng
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
| | - Chusheng Huang
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
| | - Qi Xiao
- College of Chemistry and Materials Science
- Guangxi Teachers Education University
- Nanning 530001
- P. R. China
- State Key Laboratory of Virology
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242
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Broussard GJ, Liang R, Tian L. Monitoring activity in neural circuits with genetically encoded indicators. Front Mol Neurosci 2014; 7:97. [PMID: 25538558 PMCID: PMC4256991 DOI: 10.3389/fnmol.2014.00097] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/15/2014] [Indexed: 12/18/2022] Open
Abstract
Recent developments in genetically encoded indicators of neural activity (GINAs) have greatly advanced the field of systems neuroscience. As they are encoded by DNA, GINAs can be targeted to genetically defined cellular populations. Combined with fluorescence microscopy, most notably multi-photon imaging, GINAs allow chronic simultaneous optical recordings from large populations of neurons or glial cells in awake, behaving mammals, particularly rodents. This large-scale recording of neural activity at multiple temporal and spatial scales has greatly advanced our understanding of the dynamics of neural circuitry underlying behavior—a critical first step toward understanding the complexities of brain function, such as sensorimotor integration and learning. Here, we summarize the recent development and applications of the major classes of GINAs. In particular, we take an in-depth look at the design of available GINA families with a particular focus on genetically encoded calcium indicators (GCaMPs), sensors probing synaptic activity, and genetically encoded voltage indicators. Using the family of the GCaMP as an example, we review established sensor optimization pipelines. We also discuss practical considerations for end users of GINAs about experimental methods including approaches for gene delivery, imaging system requirements, and data analysis techniques. With the growing toolbox of GINAs and with new microscopy techniques pushing beyond their current limits, the age of light can finally achieve the goal of broad and dense sampling of neuronal activity across time and brain structures to obtain a dynamic picture of brain function.
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Affiliation(s)
- Gerard J Broussard
- Department of Biochemistry and Molecular Medicine, University of California Davis Davis, CA, USA ; Neuroscience Graduate Group, University of California Davis Davis, CA, USA
| | - Ruqiang Liang
- Department of Biochemistry and Molecular Medicine, University of California Davis Davis, CA, USA
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, University of California Davis Davis, CA, USA ; Neuroscience Graduate Group, University of California Davis Davis, CA, USA
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243
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Feierstein CE, Portugues R, Orger MB. Seeing the whole picture: A comprehensive imaging approach to functional mapping of circuits in behaving zebrafish. Neuroscience 2014; 296:26-38. [PMID: 25433239 DOI: 10.1016/j.neuroscience.2014.11.046] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 11/07/2014] [Accepted: 11/19/2014] [Indexed: 11/17/2022]
Abstract
In recent years, the zebrafish has emerged as an appealing model system to tackle questions relating to the neural circuit basis of behavior. This can be attributed not just to the growing use of genetically tractable model organisms, but also in large part to the rapid advances in optical techniques for neuroscience, which are ideally suited for application to the small, transparent brain of the larval fish. Many characteristic features of vertebrate brains, from gross anatomy down to particular circuit motifs and cell-types, as well as conserved behaviors, can be found in zebrafish even just a few days post fertilization, and, at this early stage, the physical size of the brain makes it possible to analyze neural activity in a comprehensive fashion. In a recent study, we used a systematic and unbiased imaging method to record the pattern of activity dynamics throughout the whole brain of larval zebrafish during a simple visual behavior, the optokinetic response (OKR). This approach revealed the broadly distributed network of neurons that were active during the behavior and provided insights into the fine-scale functional architecture in the brain, inter-individual variability, and the spatial distribution of behaviorally relevant signals. Combined with mapping anatomical and functional connectivity, targeted electrophysiological recordings, and genetic labeling of specific populations, this comprehensive approach in zebrafish provides an unparalleled opportunity to study complete circuits in a behaving vertebrate animal.
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Affiliation(s)
- C E Feierstein
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Avenida Brasília, Doca de Pedrouços, Lisbon 1400-038, Portugal
| | - R Portugues
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152, Germany
| | - M B Orger
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Avenida Brasília, Doca de Pedrouços, Lisbon 1400-038, Portugal.
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244
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Affiliation(s)
- Michael Häusser
- Wolfson Institute for Biomedical Research and in the Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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245
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Rose T, Goltstein PM, Portugues R, Griesbeck O. Putting a finishing touch on GECIs. Front Mol Neurosci 2014; 7:88. [PMID: 25477779 PMCID: PMC4235368 DOI: 10.3389/fnmol.2014.00088] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/29/2014] [Indexed: 01/12/2023] Open
Abstract
More than a decade ago genetically encoded calcium indicators (GECIs) entered the stage as new promising tools to image calcium dynamics and neuronal activity in living tissues and designated cell types in vivo. From a variety of initial designs two have emerged as promising prototypes for further optimization: FRET (Förster Resonance Energy Transfer)-based sensors and single fluorophore sensors of the GCaMP family. Recent efforts in structural analysis, engineering and screening have broken important performance thresholds in the latest generation for both classes. While these improvements have made GECIs a powerful means to perform physiology in living animals, a number of other aspects of sensor function deserve attention. These aspects include indicator linearity, toxicity and slow response kinetics. Furthermore creating high performance sensors with optically more favorable emission in red or infrared wavelengths as well as new stably or conditionally GECI-expressing animal lines are on the wish list. When the remaining issues are solved, imaging of GECIs will finally have crossed the last milestone, evolving from an initial promise into a fully matured technology.
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Affiliation(s)
- Tobias Rose
- Max-Planck-Institute of Neurobiology Martinsried, Germany
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246
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Fluorescent-protein-based probes: general principles and practices. Anal Bioanal Chem 2014; 407:9-15. [PMID: 25326886 DOI: 10.1007/s00216-014-8236-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 09/17/2014] [Accepted: 10/02/2014] [Indexed: 01/05/2023]
Abstract
An important application of fluorescent proteins is to derive genetically encoded fluorescent probes that can actively respond to cellular dynamics such as pH change, redox signaling, calcium oscillation, enzyme activities, and membrane potential. Despite the large diverse group of fluorescent-protein-based probes, a few basic principles have been established and are shared by most of these probes. In this article, the focus is on these general principles and strategies that guide the development of fluorescent-protein-based probes. A few examples are provided in each category to illustrate the corresponding principles. Since these principles are quite straightforward, others may adapt them to create fluorescent probes for their own interest. Hopefully, the development of the ever-growing family of fluorescent-protein-based probes will no longer be limited to a small number of laboratories specialized in senor development, leading to the situation that biological studies will be bettered assisted by genetically encoded sensors.
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247
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Murphey DK, Herman AM, Arenkiel BR. Dissecting inhibitory brain circuits with genetically-targeted technologies. Front Neural Circuits 2014; 8:124. [PMID: 25368555 PMCID: PMC4201106 DOI: 10.3389/fncir.2014.00124] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 09/22/2014] [Indexed: 12/14/2022] Open
Abstract
The evolution of genetically targeted tools has begun to allow us to dissect anatomically and functionally heterogeneous interneurons, and to probe circuit function from synapses to behavior. Over the last decade, these tools have been used widely to visualize neurons in a cell type-specific manner, and engage them to activate and inactivate with exquisite precision. In this process, we have expanded our understanding of interneuron diversity, their functional connectivity, and how selective inhibitory circuits contribute to behavior. Here we discuss the relative assets of genetically encoded fluorescent proteins (FPs), viral tracing methods, optogenetics, chemical genetics, and biosensors in the study of inhibitory interneurons and their respective circuits.
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Affiliation(s)
- Dona K Murphey
- Department of Neurology, Baylor College of Medicine Houston, TX, USA
| | - Alexander M Herman
- Program in Developmental Biology, Baylor College of Medicine Houston, TX, USA
| | - Benjamin R Arenkiel
- Program in Developmental Biology, Baylor College of Medicine Houston, TX, USA ; Department of Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA ; Department of Neuroscience, Baylor College of Medicine Houston, TX, USA ; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital Houston, TX, USA
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248
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Lindenburg LH, Malisauskas M, Sips T, van Oppen L, Wijnands SPW, van de Graaf SFJ, Merkx M. Quantifying stickiness: thermodynamic characterization of intramolecular domain interactions to guide the design of förster resonance energy transfer sensors. Biochemistry 2014; 53:6370-81. [PMID: 25216081 DOI: 10.1021/bi500433j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The introduction of weak, hydrophobic interactions between fluorescent protein domains (FPs) can substantially increase the dynamic range (DR) of Förster resonance energy transfer (FRET)-based sensor systems. Here we report a comprehensive thermodynamic characterization of the stability of a range of self-associating FRET pairs. A new method is introduced that allows direct quantification of the stability of weak FP interactions by monitoring intramolecular complex formation as a function of urea concentration. The commonly used S208F mutation stabilized intramolecular FP complex formation by 2.0 kCal/mol when studied in an enhanced cyan FP (ECFP)-linker-enhanced yellow FP (EYFP) fusion protein, whereas a significantly weaker interaction was observed for the homologous Cerulean/Citrine FRET pair (ΔG0(o-c) = 0.62 kCal/mol). The latter effect could be attributed to two mutations in Cerulean (Y145A and H148D) that destabilize complex formation with Citrine. Systematic analysis of the contribution of residues 125 and 127 at the dimerization interface in mOrange.linker.mCherry fusion proteins yielded a toolbox of new mOrange-mCherry combinations that allowed tuning of their intramolecular interaction from very weak (ΔG0(o-c) = .0.39 kCal/mol) to relatively stable (ΔG0(o-c) = 2.2 kCal/mol). The effects of these mutations were also studied by monitoring homodimerization of mCherry variants using fluorescence anisotropy. These mutations affected intramolecular and intermolecular domain interactions similarly, although FP interactions were found to be stronger in the latter. The knowledge thus obtained allowed successful construction of a red-shifted variant of the bile acid FRET sensor BAS-1 by replacement of the self-associating Cerulean-Citrine pair by mOrange.mCherry variants with a similar intramolecular affinity. Our findings thus allow a better understanding of the subtle but important role of intramolecular domain interactions in current FRET sensors and help guide the construction of new sensors using modular design strategies.
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Affiliation(s)
- Laurens H Lindenburg
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands
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249
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Oheim M, van 't Hoff M, Feltz A, Zamaleeva A, Mallet JM, Collot M. New red-fluorescent calcium indicators for optogenetics, photoactivation and multi-color imaging. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1843:2284-306. [PMID: 24681159 DOI: 10.1016/j.bbamcr.2014.03.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 03/09/2014] [Indexed: 01/15/2023]
Abstract
Most chemical and, with only a few exceptions, all genetically encoded fluorimetric calcium (Ca(2+)) indicators (GECIs) emit green fluorescence. Many of these probes are compatible with red-emitting cell- or organelle markers. But the bulk of available fluorescent-protein constructs and transgenic animals incorporate green or yellow fluorescent protein (GFP and YFP respectively). This is, in part, not only heritage from the tendency to aggregate of early-generation red-emitting FPs, and due to their complicated photochemistry, but also resulting from the compatibility of green-fluorescent probes with standard instrumentation readily available in most laboratories and core imaging facilities. Photochemical constraints like limited water solubility and low quantum yield have contributed to the relative paucity of red-emitting Ca(2+) probes compared to their green counterparts, too. The increasing use of GFP and GFP-based functional reporters, together with recent developments in optogenetics, photostimulation and super-resolution microscopies, has intensified the quest for red-emitting Ca(2+) probes. In response to this demand more red-emitting chemical and FP-based Ca(2+)-sensitive indicators have been developed since 2009 than in the thirty years before. In this topical review, we survey the physicochemical properties of these red-emitting Ca(2+) probes and discuss their utility for biological Ca(2+) imaging. Using the spectral separability index Xijk (Oheim M., 2010. Methods in Molecular Biology 591: 3-16) we evaluate their performance for multi-color excitation/emission experiments, involving the identification of morphological landmarks with GFP/YFP and detecting Ca(2+)-dependent fluorescence in the red spectral band. We also establish a catalog of criteria for evaluating Ca(2+) indicators that ideally should be made available for each probe. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Martin Oheim
- CNRS, UMR 8154, Paris F-75006, France; INSERM, U603, Paris F-75006, France; University Paris Descartes, PRES Sorbonne Paris Cité, Laboratory of Neurophysiology and New Microscopies, 45 rue des Saints Pères, Paris F-75006, France.
| | - Marcel van 't Hoff
- CNRS, UMR 8154, Paris F-75006, France; INSERM, U603, Paris F-75006, France; University Paris Descartes, PRES Sorbonne Paris Cité, Laboratory of Neurophysiology and New Microscopies, 45 rue des Saints Pères, Paris F-75006, France; University of Florence, LENS - European Laboratory for Non-linear Spectroscopy, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy
| | - Anne Feltz
- Ecole Normale Supérieure, Institut de Biologie de l'ENS (IBENS), Paris F-75005, France; INSERM U1024, Paris F-75005, France; CNRS UMR 8197, Paris F-75005, France
| | - Alsu Zamaleeva
- Ecole Normale Supérieure, Institut de Biologie de l'ENS (IBENS), Paris F-75005, France; INSERM U1024, Paris F-75005, France; CNRS UMR 8197, Paris F-75005, France
| | - Jean-Maurice Mallet
- UPMC Université́ Paris 06, Ecole Normale Supérieure (ENS), 24 rue Lhomond, Paris F-75005, France; CNRS UMR 7203, Paris F-75005, France
| | - Mayeul Collot
- UPMC Université́ Paris 06, Ecole Normale Supérieure (ENS), 24 rue Lhomond, Paris F-75005, France; CNRS UMR 7203, Paris F-75005, France
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250
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Badura A, Sun XR, Giovannucci A, Lynch LA, Wang SSH. Fast calcium sensor proteins for monitoring neural activity. NEUROPHOTONICS 2014; 1:025008. [PMID: 25558464 PMCID: PMC4280659 DOI: 10.1117/1.nph.1.2.025008] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/12/2014] [Accepted: 09/23/2014] [Indexed: 05/18/2023]
Abstract
A major goal of the BRAIN Initiative is the development of technologies to monitor neuronal network activity during active information processing. Toward this goal, genetically encoded calcium indicator proteins have become widely used for reporting activity in preparations ranging from invertebrates to awake mammals. However, slow response times, the narrow sensitivity range of Ca2+ and in some cases, poor signal-to-noise ratio still limit their usefulness. Here, we review recent improvements in the field of neural activity-sensitive probe design with a focus on the GCaMP family of calcium indicator proteins. In this context, we present our newly developed Fast-GCaMPs, which have up to 4-fold accelerated off-responses compared with the next-fastest GCaMP, GCaMP6f. Fast-GCaMPs were designed by destabilizing the association of the hydrophobic pocket of calcium-bound calmodulin with the RS20 binding domain, an intramolecular interaction that protects the green fluorescent protein chromophore. Fast-GCaMP6f-RS06 and Fast-GCaMP6f-RS09 have rapid off-responses in stopped-flow fluorimetry, in neocortical brain slices, and in the intact cerebellum in vivo. Fast-GCaMP6f variants should be useful for tracking action potentials closely spaced in time, and for following neural activity in fast-changing compartments, such as axons and dendrites. Finally, we discuss strategies that may allow tracking of a wider range of neuronal firing rates and improve spike detection.
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Affiliation(s)
- Aleksandra Badura
- Princeton University, Princeton Neuroscience Institute and Department of Molecular Biology, Princeton, New Jersey 08544, United States
| | - Xiaonan Richard Sun
- Princeton University, Princeton Neuroscience Institute and Department of Molecular Biology, Princeton, New Jersey 08544, United States
| | - Andrea Giovannucci
- Princeton University, Princeton Neuroscience Institute and Department of Molecular Biology, Princeton, New Jersey 08544, United States
| | - Laura A. Lynch
- Princeton University, Princeton Neuroscience Institute and Department of Molecular Biology, Princeton, New Jersey 08544, United States
| | - Samuel S.-H. Wang
- Princeton University, Princeton Neuroscience Institute and Department of Molecular Biology, Princeton, New Jersey 08544, United States
- Address all correspondence to: Sam Wang, E-mail:
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