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Raspe R, Günther R, Uecker R, Rakhymzhan A, Paul F, Radbruch H, Niesner RA, Hauser AE. Multimodal Longitudinal Optical Imaging Reveals Optic Neuritis Preceding Retinal Pathology in Experimental Autoimmune Encephalomyelitis. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2025; 12:e200338. [PMID: 39661921 PMCID: PMC11637508 DOI: 10.1212/nxi.0000000000200338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Accepted: 09/18/2024] [Indexed: 12/13/2024]
Abstract
BACKGROUND AND OBJECTIVES Inflammatory demyelinating diseases of the CNS, chief among them multiple sclerosis (MS), are a major cause of disability in young adults. Early manifestations of MS commonly involve visual dysfunction, which is often caused by optic neuritis and is accompanied by quantifiable structural changes of the anterior visual pathway. Retinal optical coherence tomography (OCT) has emerged as an important tool for clinical assessment of these structural alterations, but the underlying pathobiological mechanisms and temporal dynamics are yet poorly understood at a cellular level. METHODS Using the experimental autoimmune encephalomyelitis (EAE) model of MS in fluorescent reporter mouse strains for neuronal function and innate immune cells, we use a unique combination of retinal intravital 2-photon microscopy (2PM) and OCT. In this fashion, we elucidate the spatiotemporal interplay of functional and structural retinal changes over the course of 1 month after EAE induction, with histopathologic imaging validating main results. RESULTS While all mice display histologic signs of optic neuritis early after EAE induction and independently of motor symptom severity, retinal signs of neuronal stress and parenchymal immune activation spike well after clinical peak of disease, with no signs of lasting structural damage appearing within 1 month after EAE induction. Thus, local retinal endpoints appear to be functions of downstream axonal damage rather than of immediate immune activation directed at the retina. However, as early as 1 week after EAE induction, retinal 2PM can detect recruitment of perivascular immune cells towards the optic nerve (ON), providing the earliest sign of disease activity in otherwise clinically inconspicuous mice. DISCUSSION Our work identifies the recruitment of CX3CR1+ cells to the ON as an early sign of disease underlining the importance of combined structural and functional retinal imaging for the spatiotemporal characterization of neuroinflammatory and neurodegenerative processes. It further proposes retinal phagocyte orientation, morphology, and abundance as potential surrogate markers for neurodegenerative activity.
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Affiliation(s)
- Raphael Raspe
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Robert Günther
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Ralf Uecker
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Asylkhan Rakhymzhan
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Friedemann Paul
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Helena Radbruch
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Raluca Aura Niesner
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
| | - Anja Erika Hauser
- From the Departments of Rheumatology and Clinical Immunology (R.R., A.E.H., R.U.) and Neuropathology (R.R., H.R.), Charité - Universitätsmedizin Berlin; Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Immune Dynamics (A.E.H., R.G.) and Biophysical Analytics (A.R., R.A.N.), Berlin; NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin (F.P.), Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin and Max-Delbrueck Center for Molecular Medicine (F.P.); and Dynamic and Functional in vivo Imaging, Freie Universität (R.A.N.) Berlin, Germany
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Barroso M, Monaghan MG, Niesner R, Dmitriev RI. Probing organoid metabolism using fluorescence lifetime imaging microscopy (FLIM): The next frontier of drug discovery and disease understanding. Adv Drug Deliv Rev 2023; 201:115081. [PMID: 37647987 PMCID: PMC10543546 DOI: 10.1016/j.addr.2023.115081] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/20/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023]
Abstract
Organoid models have been used to address important questions in developmental and cancer biology, tissue repair, advanced modelling of disease and therapies, among other bioengineering applications. Such 3D microenvironmental models can investigate the regulation of cell metabolism, and provide key insights into the mechanisms at the basis of cell growth, differentiation, communication, interactions with the environment and cell death. Their accessibility and complexity, based on 3D spatial and temporal heterogeneity, make organoids suitable for the application of novel, dynamic imaging microscopy methods, such as fluorescence lifetime imaging microscopy (FLIM) and related decay time-assessing readouts. Several biomarkers and assays have been proposed to study cell metabolism by FLIM in various organoid models. Herein, we present an expert-opinion discussion on the principles of FLIM and PLIM, instrumentation and data collection and analysis protocols, and general and emerging biosensor-based approaches, to highlight the pioneering work being performed in this field.
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Affiliation(s)
- Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA
| | - Michael G Monaghan
- Department of Mechanical, Manufacturing and Biomedical Engineering, Trinity College Dublin, Dublin 02, Ireland
| | - Raluca Niesner
- Dynamic and Functional In Vivo Imaging, Freie Universität Berlin and Biophysical Analytics, German Rheumatism Research Center, Berlin, Germany
| | - Ruslan I Dmitriev
- Tissue Engineering and Biomaterials Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium; Ghent Light Microscopy Core, Ghent University, 9000 Ghent, Belgium.
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Ulbricht C, Leben R, Cao Y, Niesner RA, Hauser AE. Combined FRET-FLIM and NAD(P)H FLIM to Analyze B Cell Receptor Signaling Induced Metabolic Activity of Germinal Center B Cells In Vivo. Methods Mol Biol 2023; 2654:91-111. [PMID: 37106177 DOI: 10.1007/978-1-0716-3135-5_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Affinity maturation of B cell clones within germinal centers constitutes an important mechanism for immune memory. During this process, B cell receptor signaling capacity is tested in multiple rounds of positive selection. Antigen stimulation and co-stimulatory signals mobilize calcium to switch on gene expression leading to proliferation and survival and to differentiation into memory B cells and plasma cells. Additionally, all these processes require adaption of B cell metabolism, and calcium signaling and metabolic pathways are closely interlinked. Mitochondrial adaption, ROS production, and NADPH oxidase activation are involved in cell fate decisions, but it remains elusive to what extent, especially because the analysis of these dynamic processes in germinal centers has to take place in vivo. Here, we introduce a quantitative intravital imaging method for combined measurement of cytoplasmic calcium concentration and enzymatic fingerprinting in germinal center B cells as a possible tool in order to further examine the relationship of calcium signaling and immunometabolism.
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Affiliation(s)
- Carolin Ulbricht
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Rheumatology and Clinical Immunology, Berlin, Germany
- Immune Dynamics, Deutsches Rheuma-Forschungszentrum (DRFZ), a Leibniz Institute, Berlin, Germany
| | - Ruth Leben
- Biophysical Analysis, Deutsches Rheuma-Forschungszentrum (DRFZ), a Leibniz Institute, Berlin, Germany
- Dynamic and functional in vivo imaging, Freie Universität Berlin, Veterinary Medicine, Berlin, Germany
| | - Yu Cao
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Rheumatology and Clinical Immunology, Berlin, Germany
- Immune Dynamics, Deutsches Rheuma-Forschungszentrum (DRFZ), a Leibniz Institute, Berlin, Germany
| | - Raluca A Niesner
- Biophysical Analysis, Deutsches Rheuma-Forschungszentrum (DRFZ), a Leibniz Institute, Berlin, Germany
- Dynamic and functional in vivo imaging, Freie Universität Berlin, Veterinary Medicine, Berlin, Germany
| | - Anja E Hauser
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Rheumatology and Clinical Immunology, Berlin, Germany.
- Immune Dynamics, Deutsches Rheuma-Forschungszentrum (DRFZ), a Leibniz Institute, Berlin, Germany.
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Leben R, Lindquist RL, Hauser AE, Niesner R, Rakhymzhan A. Two-Photon Excitation Spectra of Various Fluorescent Proteins within a Broad Excitation Range. Int J Mol Sci 2022; 23:13407. [PMID: 36362194 PMCID: PMC9656010 DOI: 10.3390/ijms232113407] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 03/26/2024] Open
Abstract
Two-photon excitation fluorescence laser-scanning microscopy is the preferred method for studying dynamic processes in living organ models or even in living organisms. Thanks to near-infrared and infrared excitation, it is possible to penetrate deep into the tissue, reaching areas of interest relevant to life sciences and biomedicine. In those imaging experiments, two-photon excitation spectra are needed to select the optimal laser wavelength to excite as many fluorophores as possible simultaneously in the sample under consideration. The more fluorophores that can be excited, and the more cell populations that can be studied, the better access to their arrangement and interaction can be reached in complex systems such as immunological organs. However, for many fluorophores, the two-photon excitation properties are poorly predicted from the single-photon spectra and are not yet available, in the literature or databases. Here, we present the broad excitation range (760 nm to 1300 nm) of photon-flux-normalized two-photon spectra of several fluorescent proteins in their cellular environment. This includes the following fluorescent proteins spanning from the cyan to the infrared part of the spectrum: mCerulean3, mTurquoise2, mT-Sapphire, Clover, mKusabiraOrange2, mOrange2, LSS-mOrange, mRuby2, mBeRFP, mCardinal, iRFP670, NirFP, and iRFP720.
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Affiliation(s)
- Ruth Leben
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany
- Institute of Immunology, Center for Infection Medicine, Freie Universität Berlin, 14163 Berlin, Germany
| | - Randall L. Lindquist
- Immune Dynamics and Intravital Microscopy, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany
- Praxen für Nuklearmedizin, 12163 Berlin, Germany
| | - Anja E. Hauser
- Immune Dynamics and Intravital Microscopy, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany
- Rheumatology and Clinical Immunology, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Raluca Niesner
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany
- Dynamic and Functional In Vivo Imaging, Freie Universität Berlin, 14163 Berlin, Germany
| | - Asylkhan Rakhymzhan
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany
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Zhang Y, Guldner IH, Nichols EL, Benirschke D, Smith CJ, Zhang S, Howard SS. Instant FLIM enables 4D in vivo lifetime imaging of intact and injured zebrafish and mouse brains. OPTICA 2021; 8:885-897. [PMID: 39867356 PMCID: PMC11759494 DOI: 10.1364/optica.426870] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 05/12/2021] [Indexed: 01/28/2025]
Abstract
Traditional fluorescence microscopy is blind to molecular microenvironment information that is present in fluorescence lifetime, which can be measured by fluorescence lifetime imaging microscopy (FLIM). However, most existing FLIM techniques are slow to acquire and process lifetime images, difficult to implement, and expensive. Here, we present instant FLIM, an analog signal processing method that allows real-time streaming of fluorescence intensity, lifetime, and phasor imaging data through simultaneous image acquisition and instantaneous data processing. Instant FLIM can be easily implemented by upgrading an existing two-photon microscope using cost-effective components and our open-source software. We further improve the functionality, penetration depth, and resolution of instant FLIM using phasor segmentation, adaptive optics, and super-resolution techniques. We demonstrate through-skull intravital 3D FLIM of mouse brains to depths of 300 μm and present the first in vivo 4D FLIM of microglial dynamics in intact and injured zebrafish and mouse brains up to 12 hours.
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Affiliation(s)
- Yide Zhang
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ian H. Guldner
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Mike and Josie Harper Cancer Research Institute, University of Notre Dame, IN 46556, USA
- Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN 46202, USA
| | - Evan L. Nichols
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Center for Stem Cells and Regenerative Medicine, University of Notre Dame, IN 46556, USA
| | - David Benirschke
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Cody J. Smith
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Center for Stem Cells and Regenerative Medicine, University of Notre Dame, IN 46556, USA
| | - Siyuan Zhang
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Mike and Josie Harper Cancer Research Institute, University of Notre Dame, IN 46556, USA
- Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN 46202, USA
| | - Scott S. Howard
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
- Mike and Josie Harper Cancer Research Institute, University of Notre Dame, IN 46556, USA
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Dmitriev RI, Intes X, Barroso MM. Luminescence lifetime imaging of three-dimensional biological objects. J Cell Sci 2021; 134:1-17. [PMID: 33961054 PMCID: PMC8126452 DOI: 10.1242/jcs.254763] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A major focus of current biological studies is to fill the knowledge gaps between cell, tissue and organism scales. To this end, a wide array of contemporary optical analytical tools enable multiparameter quantitative imaging of live and fixed cells, three-dimensional (3D) systems, tissues, organs and organisms in the context of their complex spatiotemporal biological and molecular features. In particular, the modalities of luminescence lifetime imaging, comprising fluorescence lifetime imaging (FLI) and phosphorescence lifetime imaging microscopy (PLIM), in synergy with Förster resonance energy transfer (FRET) assays, provide a wealth of information. On the application side, the luminescence lifetime of endogenous molecules inside cells and tissues, overexpressed fluorescent protein fusion biosensor constructs or probes delivered externally provide molecular insights at multiple scales into protein-protein interaction networks, cellular metabolism, dynamics of molecular oxygen and hypoxia, physiologically important ions, and other physical and physiological parameters. Luminescence lifetime imaging offers a unique window into the physiological and structural environment of cells and tissues, enabling a new level of functional and molecular analysis in addition to providing 3D spatially resolved and longitudinal measurements that can range from microscopic to macroscopic scale. We provide an overview of luminescence lifetime imaging and summarize key biological applications from cells and tissues to organisms.
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Affiliation(s)
- Ruslan I. Dmitriev
- Tissue Engineering and Biomaterials Group, Department of
Human Structure and Repair, Faculty of Medicine and Health Sciences,
Ghent University, Ghent 9000,
Belgium
| | - Xavier Intes
- Department of Biomedical Engineering, Center for
Modeling, Simulation and Imaging for Medicine (CeMSIM),
Rensselaer Polytechnic Institute, Troy, NY
12180-3590, USA
| | - Margarida M. Barroso
- Department of Molecular and Cellular
Physiology, Albany Medical College,
Albany, NY 12208, USA
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Fast Gating for Raman Spectroscopy. SENSORS 2021; 21:s21082579. [PMID: 33916972 PMCID: PMC8067580 DOI: 10.3390/s21082579] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 11/16/2022]
Abstract
Fast gating in Raman spectroscopy is used to reject the fluorescence contribution from the sample and/or the substrate. Several techniques have been set up in the last few decades aiming either to enhance the Raman signal (CARS, SERS or Resonant Raman scattering) or to cancel out the fluorescence contribution (SERDS), and a number of reviews have already been published on these sub-topics. However, for many reasons it is sometimes necessary to reject fluorescence in traditional Raman spectroscopy, and in the last few decades a variety of papers dealt with this issue, which is still challenging due to the time scales at stake (down to picoseconds). Fast gating (<1 ns) in the time domain allows one to cut off part of the fluorescence signal and retrieve the best Raman signal, depending on the fluorescence lifetime of the sample and laser pulse duration. In particular, three different techniques have been developed to accomplish this task: optical Kerr cells, intensified Charge Coupling Devices and systems based on Single Photon Avalanche Photodiodes. The utility of time domain fast gating will be discussed, and In this work, the utility of time domain fast gating is discussed, as well as the performances of the mentioned techniques as reported in literature.
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Hwang W, Kim D, Moon S, Kim DY. Achieving a high photon count rate in digital time-correlated single photon counting using a hybrid photodetector. OPTICS EXPRESS 2021; 29:9797-9804. [PMID: 33820132 DOI: 10.1364/oe.419896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
We report an enhanced photon count rate in a digitally implemented time-correlated single-photon counting (TCSPC) system by utilizing a hybrid photodetector (HPD). In our digital TCSPC scheme, the photoelectronic responses from a single photon-sensitive photodetector are digitally analyzed through a high-speed analog-to-digital convertor (ADC). By virtue of the HPD which provides nearly a constant signal gain, the single-photon pulses can be effectively distinguished from pulses of simultaneously detected multiple photons by the pulse heights. Consequently, our digital TCSPC system can selectively collect single-photon signals even in the presence of intense multi-photon detections with its temporal accuracy not to be compromised. In our experiment of fluorescence lifetime measurement, the maximum count rate of single photons nearly reached the theoretical limit given by the Poisson statistics. This demonstrated that the digital TCSPC combined with the HPD provides an ultimate solution for the TCSPC implementation for high photon count rates.
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Ulbricht C, Leben R, Rakhymzhan A, Kirchhoff F, Nitschke L, Radbruch H, Niesner RA, Hauser AE. Intravital quantification reveals dynamic calcium concentration changes across B cell differentiation stages. eLife 2021; 10:56020. [PMID: 33749591 PMCID: PMC8060033 DOI: 10.7554/elife.56020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 03/19/2021] [Indexed: 01/31/2023] Open
Abstract
Calcium is a universal second messenger present in all eukaryotic cells. The mobilization and storage of Ca2+ ions drives a number of signaling-related processes, stress-responses, or metabolic changes, all of which are relevant for the development of immune cells and their adaption to pathogens. Here, we introduce the Förster resonance energy transfer (FRET)-reporter mouse YellowCaB expressing the genetically encoded calcium indicator TN-XXL in B lymphocytes. Calcium-induced conformation change of TN-XXL results in FRET-donor quenching measurable by two-photon fluorescence lifetime imaging. For the first time, using our novel numerical analysis, we extract absolute cytoplasmic calcium concentrations in activated B cells during affinity maturation in vivo. We show that calcium in activated B cells is highly dynamic and that activation introduces a persistent calcium heterogeneity to the lineage. A characterization of absolute calcium concentrations present at any time within the cytosol is therefore of great value for the understanding of long-lived beneficial immune responses and detrimental autoimmunity.
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Affiliation(s)
- Carolin Ulbricht
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Rheumatology and Clinical Immunology, Charitéplatz 1, Berlin, Germany.,Immune Dynamics, Deutsches Rheuma-Forschungszentrum Berlin, ein Institut der Leibniz-Gemeinschaft, Berlin, Germany
| | - Ruth Leben
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum, ein Institut der Leibniz-Gemeinschaft, Berlin, Germany
| | - Asylkhan Rakhymzhan
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum, ein Institut der Leibniz-Gemeinschaft, Berlin, Germany
| | | | - Lars Nitschke
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Helena Radbruch
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Neuropathology, Charitéplatz 1, Berlin, Germany
| | - Raluca A Niesner
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum, ein Institut der Leibniz-Gemeinschaft, Berlin, Germany.,Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Anja E Hauser
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Rheumatology and Clinical Immunology, Charitéplatz 1, Berlin, Germany.,Immune Dynamics, Deutsches Rheuma-Forschungszentrum Berlin, ein Institut der Leibniz-Gemeinschaft, Berlin, Germany
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Liput DJ, Nguyen TA, Augustin SM, Lee JO, Vogel SS. A Guide to Fluorescence Lifetime Microscopy and Förster's Resonance Energy Transfer in Neuroscience. CURRENT PROTOCOLS IN NEUROSCIENCE 2020; 94:e108. [PMID: 33232577 PMCID: PMC8274369 DOI: 10.1002/cpns.108] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fluorescence lifetime microscopy (FLIM) and Förster's resonance energy transfer (FRET) are advanced optical tools that neuroscientists can employ to interrogate the structure and function of complex biological systems in vitro and in vivo using light. In neurobiology they are primarily used to study protein-protein interactions, to study conformational changes in protein complexes, and to monitor genetically encoded FRET-based biosensors. These methods are ideally suited to optically monitor changes in neurons that are triggered optogenetically. Utilization of this technique by neuroscientists has been limited, since a broad understanding of FLIM and FRET requires familiarity with the interactions of light and matter on a quantum mechanical level, and because the ultra-fast instrumentation used to measure fluorescent lifetimes and resonance energy transfer are more at home in a physics lab than in a biology lab. In this overview, we aim to help neuroscientists overcome these obstacles and thus feel more comfortable with the FLIM-FRET method. Our goal is to aid researchers in the neuroscience community to achieve a better understanding of the fundamentals of FLIM-FRET and encourage them to fully leverage its powerful ability as a research tool. Published 2020. U.S. Government.
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Affiliation(s)
- Daniel J. Liput
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
- Laboratory of Molecular Physiology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Tuan A. Nguyen
- Laboratory of Biophotonics and Quantum Biology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Shana M. Augustin
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Jeong Oen Lee
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Steven S. Vogel
- Laboratory of Biophotonics and Quantum Biology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
- Corresponding author:
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Sagar MAK, Cheng KP, Ouellette JN, Williams JC, Watters JJ, Eliceiri KW. Machine Learning Methods for Fluorescence Lifetime Imaging (FLIM) Based Label-Free Detection of Microglia. Front Neurosci 2020; 14:931. [PMID: 33013309 PMCID: PMC7497798 DOI: 10.3389/fnins.2020.00931] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 08/11/2020] [Indexed: 12/22/2022] Open
Abstract
Automated computational analysis techniques utilizing machine learning have been demonstrated to be able to extract more data from different imaging modalities compared to traditional analysis techniques. One new approach is to use machine learning techniques to existing multiphoton imaging modalities to better interpret intrinsically fluorescent cellular signals to characterize different cell types. Fluorescence Lifetime Imaging Microscopy (FLIM) is a high-resolution quantitative imaging tool that can detect metabolic cellular signatures based on the lifetime variations of intrinsically fluorescent metabolic co-factors such as nicotinamide adenine dinucleotide [NAD(P)H]. NAD(P)H lifetime-based discrimination techniques have previously been used to develop metabolic cell signatures for diverse cell types including immune cells such as macrophages. However, FLIM could be even more effective in characterizing cell types if machine learning was used to classify cells by utilizing FLIM parameters for classification. Here, we demonstrate the potential for FLIM-based, label-free NAD(P)H imaging to distinguish different cell types using Artificial Neural Network (ANN)-based machine learning. For our biological use case, we used the challenge of differentiating microglia from other glia cell types in the brain. Microglia are the resident macrophages of the brain and spinal cord and play a critical role in maintaining the neural environment and responding to injury. Microglia are challenging to identify as most fluorescent labeling approaches cross-react with other immune cell types, are often insensitive to activation state, and require the use of multiple specialized antibody labels. Furthermore, the use of these extrinsic antibody labels prevents application in in vivo animal models and possible future clinical adaptations such as neurodegenerative pathologies. With the ANN-based NAD(P)H FLIM analysis approach, we found that microglia in cell culture mixed with other glial cells can be identified with more than 0.9 True Positive Rate (TPR). We also extended our approach to identify microglia in fixed brain tissue with a TPR of 0.79. In both cases the False Discovery Rate was around 30%. This method can be further extended to potentially study and better understand microglia’s role in neurodegenerative disease with improved detection accuracy.
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Affiliation(s)
- Md Abdul Kader Sagar
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States.,Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI, United States
| | - Kevin P Cheng
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Jonathan N Ouellette
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States.,Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI, United States
| | - Justin C Williams
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Jyoti J Watters
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Kevin W Eliceiri
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States.,Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI, United States.,Morgridge Institute for Research, Madison, WI, United States
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12
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Okkelman IA, McGarrigle R, O’Carroll S, Berrio DC, Schenke-Layland K, Hynes J, Dmitriev RI. Extracellular Ca2+-Sensing Fluorescent Protein Biosensor Based on a Collagen-Binding Domain. ACS APPLIED BIO MATERIALS 2020; 3:5310-5321. [DOI: 10.1021/acsabm.0c00649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Irina A. Okkelman
- Metabolic Imaging Group, Laboratory of Biophysics and Bioanalysis, ABCRF, University College Cork, College Road, Cork T12 YN60, Ireland
| | - Ryan McGarrigle
- Agilent Technologies Ireland Limited, Little
Island T45 WK12, Cork, Ireland
| | - Shane O’Carroll
- Metabolic Imaging Group, Laboratory of Biophysics and Bioanalysis, ABCRF, University College Cork, College Road, Cork T12 YN60, Ireland
| | - Daniel Carvajal Berrio
- Department of Women’s Health, Research Institute for Women’s Health, Eberhard Karls University Tübingen, Tübingen 72074, Germany
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies” (iFIT), Eberhard Karls University Tübingen, Geschwister-Scholl-Platz, Tübingen 72074, Germany
| | - Katja Schenke-Layland
- Department of Women’s Health, Research Institute for Women’s Health, Eberhard Karls University Tübingen, Tübingen 72074, Germany
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies” (iFIT), Eberhard Karls University Tübingen, Geschwister-Scholl-Platz, Tübingen 72074, Germany
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen 72770, Germany
- Department of Medicine/Cardiology, Cardiovascular Research Laboratories, David Geffen School of Medicine at UCLA, Los Angeles 90095, California, United States
| | - James Hynes
- Agilent Technologies Ireland Limited, Little
Island T45 WK12, Cork, Ireland
| | - Ruslan I. Dmitriev
- Metabolic Imaging Group, Laboratory of Biophysics and Bioanalysis, ABCRF, University College Cork, College Road, Cork T12 YN60, Ireland
- I.M. Sechenov First Moscow State University, Institute for Regenerative Medicine, Moscow 119992, Russian Federation
- Tissue Engineering and Biomaterials Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Ghent 9000, Belgium
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13
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Datta R, Heaster TM, Sharick JT, Gillette AA, Skala MC. Fluorescence lifetime imaging microscopy: fundamentals and advances in instrumentation, analysis, and applications. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-43. [PMID: 32406215 PMCID: PMC7219965 DOI: 10.1117/1.jbo.25.7.071203] [Citation(s) in RCA: 409] [Impact Index Per Article: 81.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/24/2020] [Indexed: 05/18/2023]
Abstract
SIGNIFICANCE Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to distinguish the unique molecular environment of fluorophores. FLIM measures the time a fluorophore remains in an excited state before emitting a photon, and detects molecular variations of fluorophores that are not apparent with spectral techniques alone. FLIM is sensitive to multiple biomedical processes including disease progression and drug efficacy. AIM We provide an overview of FLIM principles, instrumentation, and analysis while highlighting the latest developments and biological applications. APPROACH This review covers FLIM principles and theory, including advantages over intensity-based fluorescence measurements. Fundamentals of FLIM instrumentation in time- and frequency-domains are summarized, along with recent developments. Image segmentation and analysis strategies that quantify spatial and molecular features of cellular heterogeneity are reviewed. Finally, representative applications are provided including high-resolution FLIM of cell- and organelle-level molecular changes, use of exogenous and endogenous fluorophores, and imaging protein-protein interactions with Förster resonance energy transfer (FRET). Advantages and limitations of FLIM are also discussed. CONCLUSIONS FLIM is advantageous for probing molecular environments of fluorophores to inform on fluorophore behavior that cannot be elucidated with intensity measurements alone. Development of FLIM technologies, analysis, and applications will further advance biological research and clinical assessments.
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Affiliation(s)
- Rupsa Datta
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Tiffany M. Heaster
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Joe T. Sharick
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Amani A. Gillette
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
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14
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Mothes R, Ulbricht C, Leben R, Günther R, Hauser AE, Radbruch H, Niesner R. Teriflunomide Does Not Change Dynamics of Nadph Oxidase Activation and Neuronal Dysfunction During Neuroinflammation. Front Mol Biosci 2020; 7:62. [PMID: 32426367 PMCID: PMC7203781 DOI: 10.3389/fmolb.2020.00062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 03/24/2020] [Indexed: 12/22/2022] Open
Abstract
The multiple sclerosis therapeutic teriflunomide is known to block the de novo synthesis of pyrimidine in mitochondria by inhibiting the enzyme dihydroorotate-dehydrogenase (DHODH). The metabolic processes of oxidative phosphorylation and glycolysis are further possible downstream targets. In healthy adult mice, high levels of dihydroorotate-dehydrogenase (DHODH) activity are measured in the central nervous system (CNS), and DHODH inhibition may cause indirect effects on reactive oxygen species production and NADPH oxidase (NOX) mediated oxidative stress, known to be key aspects of the inflammatory response of the CNS. However, little is known about the effect of teriflunomide on the dynamics of NOX activation in CNS cells and subsequent alterations of neuronal function in vivo. In this study, we employed fluorescence lifetime imaging (FLIM) and phasor analysis of the endogeneous fluorescence of NAD(P)H (nicotinamide adenine dinucleotide phosphate) in the brain stem of mice to visualize the effect of teriflunomide on cellular metabolism. Furthermore, we simultaneously studied neuronal Ca2+ signals in transgenic mice with a FRET-based Troponin C Ca2+ sensor based (CerTN L15) quantified using FRET-FLIM. Hence, we directly correlated neuronal (dys-)function indicated by steadily elevated calcium levels with metabolic activity in neurons and surrounding CNS tissue. Employing our intravital co-registered imaging approach, we could not detect any significant alteration of NOX activation after incubation of the tissue with teriflunomide. Furthermore, we could not detect any changes of the inflammatory induced neuronal dysfunction due to local treatment with teriflunomide. Concerning drug safety, we can confirm that teriflunomide has no metabolic effects on neuronal function in the CNS tissue during neuroinflammation at concentrations expected in orally treated patients. The combined endogenous FLIM and calcium imaging approach developed by us and employed here uniquely meets the need to monitor cellular metabolism as a basic mechanism of tissue functions in vivo.
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Affiliation(s)
- Ronja Mothes
- Institute for Neuropathology, Charité Universitätsmedizin Berlin, Berlin, Germany.,Deutsches Rheumaforschungszentrum - Leibniz Institute, Berlin, Germany
| | - Carolin Ulbricht
- Deutsches Rheumaforschungszentrum - Leibniz Institute, Berlin, Germany.,Immunodyanmics and Intravital Microscopy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Ruth Leben
- Deutsches Rheumaforschungszentrum - Leibniz Institute, Berlin, Germany
| | - Robert Günther
- Deutsches Rheumaforschungszentrum - Leibniz Institute, Berlin, Germany
| | - Anja E Hauser
- Deutsches Rheumaforschungszentrum - Leibniz Institute, Berlin, Germany.,Immunodyanmics and Intravital Microscopy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Helena Radbruch
- Institute for Neuropathology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Raluca Niesner
- Deutsches Rheumaforschungszentrum - Leibniz Institute, Berlin, Germany.,Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
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15
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Morone D, Autilia FD, Schorn T, Erreni M, Doni A. Evaluation of cell metabolic adaptation in wound and tumour by Fluorescence Lifetime Imaging Microscopy. Sci Rep 2020; 10:6289. [PMID: 32286404 PMCID: PMC7156395 DOI: 10.1038/s41598-020-63203-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/20/2020] [Indexed: 12/12/2022] Open
Abstract
Acidic pH occurs in acute wounds progressing to healing as consequence of a cell metabolic adaptation in response to injury-induced tissue hypoperfusion. In tumours, high metabolic rate leads to acidosis affecting cancer progression. Acidic pH affects activities of remodelling cells in vitro. The pH measurement predicts healing in pathological wounds and success of surgical treatment of burns and chronic ulcers. However, current methods are limited to skin surface or based on detection of fluorescence intensity of specific sensitive probes that suffer of microenvironment factors. Herein, we ascertained relevance in vivo of cell metabolic adaptation in skin repair by interfering with anaerobic glycolysis. Moreover, a custom-designed skin imaging chamber, 2-Photon microscopy (2PM), fluorescence lifetime imaging (FLIM) and data mapping analyses were used to correlate maps of glycolytic activity in vivo as measurement of NADH intrinsic lifetime with areas of hypoxia and acidification in models of skin injury and cancer. The method was challenged by measuring the NADH profile by interfering with anaerobic glycolysis and oxidative phosphorylation in the mitochondrial respiratory chain. Therefore, intravital NADH FLIM represents a tool for investigating cell metabolic adaptation occurring in wounds, as well as the relationship between cell metabolism and cancer.
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Affiliation(s)
- Diego Morone
- Unit of Advanced Optical Microscopy, IRCCS, Humanitas Clinical and Research Center, Rozzano, Milan, Italy.,Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Bellinzona, Switzerland
| | - Francesca D' Autilia
- Unit of Advanced Optical Microscopy, IRCCS, Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Tilo Schorn
- Unit of Advanced Optical Microscopy, IRCCS, Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Marco Erreni
- Unit of Advanced Optical Microscopy, IRCCS, Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Andrea Doni
- Unit of Advanced Optical Microscopy, IRCCS, Humanitas Clinical and Research Center, Rozzano, Milan, Italy.
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16
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Levitt JA, Poland SP, Krstajic N, Pfisterer K, Erdogan A, Barber PR, Parsons M, Henderson RK, Ameer-Beg SM. Quantitative real-time imaging of intracellular FRET biosensor dynamics using rapid multi-beam confocal FLIM. Sci Rep 2020; 10:5146. [PMID: 32198437 PMCID: PMC7083966 DOI: 10.1038/s41598-020-61478-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/14/2020] [Indexed: 01/21/2023] Open
Abstract
Fluorescence lifetime imaging (FLIM) is a quantitative, intensity-independent microscopical method for measurement of diverse biochemical and physical properties in cell biology. It is a highly effective method for measurements of Förster resonance energy transfer (FRET), and for quantification of protein-protein interactions in cells. Time-domain FLIM-FRET measurements of these dynamic interactions are particularly challenging, since the technique requires excellent photon statistics to derive experimental parameters from the complex decay kinetics often observed from fluorophores in living cells. Here we present a new time-domain multi-confocal FLIM instrument with an array of 64 visible beamlets to achieve parallelised excitation and detection with average excitation powers of ~ 1–2 μW per beamlet. We exemplify this instrument with up to 0.5 frames per second time-lapse FLIM measurements of cAMP levels using an Epac-based fluorescent biosensor in live HeLa cells with nanometer spatial and picosecond temporal resolution. We demonstrate the use of time-dependent phasor plots to determine parameterisation for multi-exponential decay fitting to monitor the fractional contribution of the activated conformation of the biosensor. Our parallelised confocal approach avoids having to compromise on speed, noise, accuracy in lifetime measurements and provides powerful means to quantify biochemical dynamics in living cells.
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Affiliation(s)
- James A Levitt
- Microscopy Innovation Centre, Guy's Campus, Kings College, London, SE1 1UL, UK.,Richard Dimbleby Laboratories, School of Cancer and Pharmaceutical Sciences, Guy's Campus, Kings College London, London, SE1 1UL, UK
| | - Simon P Poland
- Richard Dimbleby Laboratories, School of Cancer and Pharmaceutical Sciences, Guy's Campus, Kings College London, London, SE1 1UL, UK
| | - Nikola Krstajic
- Institute for Microelectronics and Nanosystems, School of Engineering, College of Science and Engineering, University of Edinburgh, Edinburgh, EH9 3FB, UK
| | - Karin Pfisterer
- Randall Centre for Cell and Molecular Biophysics, Guy's Campus, Kings College, London, SE1 1UL, UK
| | - Ahmet Erdogan
- Institute for Microelectronics and Nanosystems, School of Engineering, College of Science and Engineering, University of Edinburgh, Edinburgh, EH9 3FB, UK
| | - Paul R Barber
- UCL Cancer Institute, Paul O'Gorman Building, University College London, London, WC1E 6DD, UK
| | - Maddy Parsons
- Randall Centre for Cell and Molecular Biophysics, Guy's Campus, Kings College, London, SE1 1UL, UK
| | - Robert K Henderson
- Institute for Microelectronics and Nanosystems, School of Engineering, College of Science and Engineering, University of Edinburgh, Edinburgh, EH9 3FB, UK
| | - Simon M Ameer-Beg
- Richard Dimbleby Laboratories, School of Cancer and Pharmaceutical Sciences, Guy's Campus, Kings College London, London, SE1 1UL, UK.
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17
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Zhu S, Xu Y, Li D. Three-observation-window time-gated algorithm for fluorescence lifetime detection. APPLIED OPTICS 2020; 59:2739-2745. [PMID: 32225823 DOI: 10.1364/ao.384342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
A novel three-observation-window time-gated algorithm that combines overlapped windows and discrete windows together is developed for accurate fluorescence lifetime extraction. The new algorithm adopting a rapid lifetime determination strategy can offer an excellent ability to precisely detect long fluorescence lifetime for fluorescence lifetime imaging microscopy. Monte Carlo simulation indicates that an extremely small relative standard deviation below 0.4% is obtained over a wide fluorescence lifetime range from 5 ns to 30 ns. The detection error of the short fluorescence lifetime less than 5 ns is further reduced by means of an adaptive window width method. In contrast to other algorithms, such as time-correlated single-photon counting and traditional gated-window methods, not only the detection range but also the measurement accuracy is dramatically enhanced.
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18
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Poudel C, Mela I, Kaminski CF. High-throughput, multi-parametric, and correlative fluorescence lifetime imaging. Methods Appl Fluoresc 2020; 8:024005. [PMID: 32028271 PMCID: PMC8208541 DOI: 10.1088/2050-6120/ab7364] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/18/2019] [Accepted: 02/06/2020] [Indexed: 12/11/2022]
Abstract
In this review, we discuss methods and advancements in fluorescence lifetime imaging microscopy that permit measurements to be performed at faster speed and higher resolution than previously possible. We review fast single-photon timing technologies and the use of parallelized detection schemes to enable high-throughput and high content imaging applications. We appraise different technological implementations of fluorescence lifetime imaging, primarily in the time-domain. We also review combinations of fluorescence lifetime with other imaging modalities to capture multi-dimensional and correlative information from a single sample. Throughout the review, we focus on applications in biomedical research. We conclude with a critical outlook on current challenges and future opportunities in this rapidly developing field.
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Affiliation(s)
- Chetan Poudel
- Department of Chemical Engineering and Biotechnology,
Philippa Fawcett Drive, University of
Cambridge, Cambridge CB3 0AS, United
Kingdom
| | - Ioanna Mela
- Department of Chemical Engineering and Biotechnology,
Philippa Fawcett Drive, University of
Cambridge, Cambridge CB3 0AS, United
Kingdom
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology,
Philippa Fawcett Drive, University of
Cambridge, Cambridge CB3 0AS, United
Kingdom
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19
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Leben R, Köhler M, Radbruch H, Hauser AE, Niesner RA. Systematic Enzyme Mapping of Cellular Metabolism by Phasor-Analyzed Label-Free NAD(P)H Fluorescence Lifetime Imaging. Int J Mol Sci 2019; 20:ijms20225565. [PMID: 31703416 PMCID: PMC6887798 DOI: 10.3390/ijms20225565] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 11/04/2019] [Indexed: 12/15/2022] Open
Abstract
In the past years, cellular metabolism of the immune system experienced a revival, as it has become clear that it is not merely responsible for the cellular energy supply, but also impacts on many signaling pathways and, thus, on diverse cellular functions. Label-free fluorescence lifetime imaging of the ubiquitous coenzymes NADH and NADPH (NAD(P)H-FLIM) makes it possible to monitor cellular metabolism in living cells and tissues and has already been applied to study metabolic changes both under physiologic and pathologic conditions. However, due to the complex distribution of NAD(P)H-dependent enzymes in cells, whose distribution continuously changes over time, a thorough interpretation of NAD(P)H-FLIM results, in particular, resolving the contribution of various enzymes to the overall metabolic activity, remains challenging. We developed a systematic framework based on angle similarities of the phase vectors and their length to analyze NAD(P)H-FLIM data of cells and tissues based on a generally valid reference system of highly abundant NAD(P)H-dependent enzymes in cells. By using our analysis framework, we retrieve information not only about the overall metabolic activity, i.e., the fraction of free to enzyme-bound NAD(P)H, but also identified the enzymes predominantly active within the sample at a certain time point with subcellular resolution. We verified the performance of the approach by applying NAD(P)H-FLIM on a stromal-like cell line and identified a different group of enzymes that were active in the cell nuclei as compared to the cytoplasm. As the systematic phasor-based analysis framework of label-free NAD(P)H-FLIM can be applied both in vitro and in vivo, it retains the unique power to enable dynamic enzyme-based metabolic investigations, at subcellular resolution, in genuine environments.
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Affiliation(s)
- Ruth Leben
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany;
- Dynamic and Functional in vivo Imaging, Freie Universität Berlin, 14163 Berlin, Germany
- Correspondence: (R.L.); (R.A.N.); Tel.: +49-30-2846-0674 (R.L.); +49-30-2846-0708 (R.A.N.)
| | - Markus Köhler
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany;
- Dynamic and Functional in vivo Imaging, Freie Universität Berlin, 14163 Berlin, Germany
| | - Helena Radbruch
- Institute for Neuropathology, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany;
| | - Anja E. Hauser
- Immune Dynamics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany;
- Immunodynamics and Intravital Microscopy, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Raluca A. Niesner
- Biophysical Analytics, Deutsches Rheuma-Forschungszentrum (DRFZ), 10117 Berlin, Germany;
- Dynamic and Functional in vivo Imaging, Freie Universität Berlin, 14163 Berlin, Germany
- Correspondence: (R.L.); (R.A.N.); Tel.: +49-30-2846-0674 (R.L.); +49-30-2846-0708 (R.A.N.)
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20
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Suhling K, Hirvonen LM, Becker W, Smietana S, Netz H, Milnes J, Conneely T, Marois AL, Jagutzki O, Festy F, Petrášek Z, Beeby A. Wide-field time-correlated single photon counting-based fluorescence lifetime imaging microscopy. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT 2019; 942:162365. [PMID: 31645797 PMCID: PMC6716551 DOI: 10.1016/j.nima.2019.162365] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 05/23/2023]
Abstract
Wide-field time-correlated single photon counting detection techniques, where the position and the arrival time of the photons are recorded simultaneously using a camera, have made some advances recently. The technology and instrumentation used for this approach is employed in areas such as nuclear science, mass spectroscopy and positron emission tomography, but here, we discuss some of the wide-field TCSPC methods, for applications in fluorescence microscopy. We describe work by us and others as presented in the Ulitima fast imaging and tracking conference at the Argonne National Laboratory in September 2018, from phosphorescence lifetime imaging (PLIM) microscopy on the microsecond time scale to fluorescence lifetime imaging (FLIM) on the nanosecond time scale, and highlight some applications of these techniques.
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Affiliation(s)
- Klaus Suhling
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
- Corresponding author.
| | - Liisa M. Hirvonen
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
| | - Wolfgang Becker
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany
| | - Stefan Smietana
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany
| | - Holger Netz
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany
| | - James Milnes
- Photek Ltd, 26 Castleham Rd, St Leonards on Sea TN38 9NS, UK
| | - Thomas Conneely
- Photek Ltd, 26 Castleham Rd, St Leonards on Sea TN38 9NS, UK
| | - Alix Le Marois
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
| | - Ottmar Jagutzki
- Institut für Kernphysik, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - Fred Festy
- Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guys Hospital, Kings Health Partners, Guys Dental Hospital, London Bridge, London SE1 9RT, UK
| | - Zdeněk Petrášek
- Institut für Biotechnologie und Bioprozesstechnik, Technische Universität Graz, Petersgasse, 10-12/I, 8010 Graz, Austria
| | - Andrew Beeby
- Department of Chemistry, University of Durham, Durham DH13LE, UK
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21
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Trinh AL, Ber S, Howitt A, Valls PO, Fries MW, Venkitaraman AR, Esposito A. Fast single-cell biochemistry: theory, open source microscopy and applications. Methods Appl Fluoresc 2019; 7:044001. [PMID: 31422954 PMCID: PMC7000240 DOI: 10.1088/2050-6120/ab3bd2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fluorescence lifetime sensing enables researchers to probe the physicochemical environment of a fluorophore providing a window through which we can observe the complex molecular make-up of the cell. Fluorescence lifetime imaging microscopy (FLIM) quantifies and maps cell biochemistry, a complex ensemble of dynamic processes. Unfortunately, typical high-resolution FLIM systems exhibit rather limited acquisition speeds, often insufficient to capture the time evolution of biochemical processes in living cells. Here, we describe the theoretical background that justifies the developments of high-speed single photon counting systems. We show that systems with low dead-times not only result in faster acquisition throughputs but also improved dynamic range and spatial resolution. We also share the implementation of hardware and software as an open platform, show applications of fast FLIM biochemical imaging on living cells and discuss strategies to balance precision and accuracy in FLIM. The recent innovations and commercialisation of fast time-domain FLIM systems are likely to popularise FLIM within the biomedical community, to impact biomedical research positively and to foster the adoption of other FLIM techniques as well. While supporting and indeed pursuing these developments, with this work we also aim to warn the community about the possible shortcomings of fast single photon counting techniques and to highlight strategies to acquire data of high quality.
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22
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Ranawat H, Pal S, Mazumder N. Recent trends in two-photon auto-fluorescence lifetime imaging (2P-FLIM) and its biomedical applications. Biomed Eng Lett 2019; 9:293-310. [PMID: 31456890 PMCID: PMC6694381 DOI: 10.1007/s13534-019-00119-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/30/2019] [Accepted: 06/27/2019] [Indexed: 02/07/2023] Open
Abstract
Two photon fluorescence microscopy and the numerous technical advances to it have served as valuable tools in biomedical research. The fluorophores (exogenous or endogenous) absorb light and emit lower energy photons than the absorption energy and the emission (fluorescence) signal is measured using a fluorescence decay graph. Additionally, high spatial resolution images can be acquired in two photon fluorescence lifetime imaging (2P-FLIM) with improved penetration depth which helps in detection of fluorescence signal in vivo. 2P-FLIM is a non-invasive imaging technique in order to visualize cellular metabolic, by tracking intrinsic fluorophores present in it, such as nicotinamide adenine dinucleotide, flavin adenine dinucleotide and tryptophan etc. 2P-FLIM of these molecules enable the visualization of metabolic alterations, non-invasively. This comprehensive review discusses the numerous applications of 2P-FLIM towards cancer, neuro-degenerative, infectious diseases, and wound healing.
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Affiliation(s)
- Harsh Ranawat
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
| | - Sagnik Pal
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
| | - Nirmal Mazumder
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
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23
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Imaging the execution phase of neuroinflammatory disease models. Exp Neurol 2019; 320:112968. [PMID: 31152743 DOI: 10.1016/j.expneurol.2019.112968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/22/2019] [Accepted: 05/28/2019] [Indexed: 12/15/2022]
Abstract
In vivo imaging of the rodent spinal cord has advanced our understanding of how resident cells of the central nervous system (CNS) respond to neuroinflammation. By combining two-photon imaging and experimental autoimmune encephalomyelitis (EAE), the most widely used rodent model of multiple sclerosis (MS), it has been possible, for example, to study how axons degenerate when confronted with inflammatory cells, how oligodendrocytes get damaged in inflammatory lesions, and how immune cells themselves adapt their phenotype and functionality to the changing lesion environment. Similar approaches are now increasingly used to study other forms of neuroinflammation, such as antibody/complement-mediated neuromyelitis optica spectrum disease (NMOSD). To tackle the most pressing open questions in the field, new biosensors and indicator mice that report the metabolic state and interaction of cells in neuroinflammatory lesions are being developed. Moreover, the field is moving towards new anatomical sites of inflammation, such as the cortical gray matter, but also towards longer observation intervals to reveal the chronic perturbations and adaptations that characterize advanced stages of MS.
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24
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Lindquist RL, Niesner RA, Hauser AE. In the Right Place, at the Right Time: Spatiotemporal Conditions Determining Plasma Cell Survival and Function. Front Immunol 2019; 10:788. [PMID: 31068930 PMCID: PMC6491733 DOI: 10.3389/fimmu.2019.00788] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/25/2019] [Indexed: 12/21/2022] Open
Abstract
Plasma cells (PCs), the B lineage cells responsible for producing and secreting antibodies (Abs), are critical cellular components of the humoral immune system. While most of the antibody-secreting cells in the body have a rather short lifetime of a few days, some of them can become long-lived and persist in the body over the entire life span of an individual. The majority of these long-lived plasma cells secretes protective antibodies against pathogens, and are thereby crucial for the humoral component of immunological memory. The generation of these protective antibody-secreting cells can be triggered by an exposure to pathogens, and also by vaccination. Although the majority of plasma cells are protective, sometimes long-lived plasma cells produce autoreactive antibodies, which contribute to the pathogenesis and perpetuation of chronic autoimmune diseases, including lupus erythematosus, rheumatoid arthritis, or multiple sclerosis. In order to promote the formation of protective antibody-secreting cells and to target pathogenic plasma cells, it is crucial to understand the signals which promote their longevity and allow them to exert their function. In recent years, it has become clear that plasma cells depend on extrinsic factors for their survival, leading to the concept that certain tissue microenvironments promote plasma cell retention and longevity. However, these niches are not static structures, but also have dynamic features with respect to their cellular composition. Here, we review what is known about the molecular and cellular composition of the niches, and discuss the impact of dynamic changes within these microenvironments on plasma cell function. As plasma cell metabolism is tightly linked to their function, we present new tools, which will allow us to analyze metabolic parameters in the plasma cell niches in vivo over time.
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Affiliation(s)
- Randall L Lindquist
- Immunodynamics, Deutsches Rheuma-Forschungszentrum Berlin, A Leibniz Institute, Berlin, Germany
| | - Raluca A Niesner
- Biophysical Analysis, Deutsches Rheuma-Forschungszentrum Berlin, A Leibniz Institute, Berlin, Germany.,Fachbereich Veterinärmedizin, Institute of Veterinary Physiology, Freie Universität Berlin, Berlin, Germany
| | - Anja E Hauser
- Immunodynamics, Deutsches Rheuma-Forschungszentrum Berlin, A Leibniz Institute, Berlin, Germany.,Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Berlin, Germany
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25
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O'Donnell N, Okkelman IA, Timashev P, Gromovykh TI, Papkovsky DB, Dmitriev RI. Cellulose-based scaffolds for fluorescence lifetime imaging-assisted tissue engineering. Acta Biomater 2018; 80:85-96. [PMID: 30261339 DOI: 10.1016/j.actbio.2018.09.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/11/2018] [Accepted: 09/23/2018] [Indexed: 12/12/2022]
Abstract
Quantitative measurement of pH and metabolite gradients by microscopy is one of the challenges in the production of scaffold-grown organoids and multicellular aggregates. Herein, we used the cellulose-binding domain (CBD) of the Cellulomonas fimi CenA protein for designing biosensor scaffolds that allow measurement of pH and Ca2+ gradients by fluorescence intensity and lifetime imaging (FLIM) detection modes. By fusing CBD with pH-sensitive enhanced cyan fluorescent protein (CBD-ECFP), we achieved efficient labeling of cellulose-based scaffolds based on nanofibrillar, bacterial cellulose, and decellularized plant materials. CBD-ECFP bound to the cellulose matrices demonstrated pH sensitivity comparable to untagged ECFP (1.9-2.3 ns for pH 6-8), thus making it compatible with FLIM-based analysis of extracellular pH. By using 3D culture of human colon cancer cells (HCT116) and adult stem cell-derived mouse intestinal organoids, we evaluated the utility of the produced biosensor scaffold. CBD-ECFP was sensitive to increases in extracellular acidification: the results showed a decline in 0.2-0.4 pH units in response to membrane depolarization by the protonophore FCCP. With the intestinal organoid model, we demonstrated multiparametric imaging by combining extracellular acidification (FLIM) with phosphorescent probe-based monitoring of cell oxygenation. The described labeling strategy allows for the design of extracellular pH-sensitive scaffolds for multiparametric FLIM assays and their use in engineered live cancer and stem cell-derived tissues. Collectively, this research can help in achieving the controlled biofabrication of 3D tissue models with known metabolic characteristics. STATEMENT OF SIGNIFICANCE: We designed biosensors consisting of a cellulose-binding domain (CBD) and pH- and Ca2+-sensitive fluorescent proteins. CBD-tagged biosensors efficiently label various types of cellulose matrices including nanofibrillar cellulose and decellularized plant materials. Hybrid biosensing cellulose scaffolds designed in this study were successfully tested by multiparameter FLIM microscopy in 3D cultures of cancer cells and mouse intestinal organoids.
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Affiliation(s)
- Neil O'Donnell
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Irina A Okkelman
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Peter Timashev
- Institute for Regenerative Medicine, I.M. Sechenov First Moscow State University, Moscow, Russian Federation; Institute of Photonic Technologies, Research Center 'Crystallography and Photonics', Russian Academy of Sciences, Moscow, Russian Federation
| | - Tatyana I Gromovykh
- Department of Biotechnology, I.M. Sechenov First Moscow State University, Moscow, Russian Federation
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Ruslan I Dmitriev
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland; Institute for Regenerative Medicine, I.M. Sechenov First Moscow State University, Moscow, Russian Federation.
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26
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Ryu J, Kang U, Kim J, Kim H, Kang JH, Kim H, Sohn DK, Jeong JH, Yoo H, Gweon B. Real-time visualization of two-photon fluorescence lifetime imaging microscopy using a wavelength-tunable femtosecond pulsed laser. BIOMEDICAL OPTICS EXPRESS 2018; 9:3449-3463. [PMID: 29984109 PMCID: PMC6033550 DOI: 10.1364/boe.9.003449] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/07/2018] [Accepted: 06/21/2018] [Indexed: 05/03/2023]
Abstract
A fluorescence lifetime imaging microscopy (FLIM) integrated with two-photon excitation technique was developed. A wavelength-tunable femtosecond pulsed laser with nominal pulse repetition rate of 76-MHz was used to acquire FLIM images with a high pixel rate of 3.91 MHz by processing the pulsed two-photon fluorescence signal. Analog mean-delay (AMD) method was adopted to accelerate the lifetime measurement process and to visualize lifetime map in real-time. As a result, rapid tomographic visualization of both structural and chemical properties of the tissues was possible with longer depth penetration and lower photo-damage compared to the conventional single-photon FLIM techniques.
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Affiliation(s)
- Jiheun Ryu
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
- Wellman Center for Photomedicine, Harvard Medical School & Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Ungyo Kang
- Department of Biomedical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Jayul Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Hyunjun Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Jue Hyung Kang
- Department of Biomedical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Hyunjin Kim
- Molecular Imaging & Therapy Branch, Research Institute and Hospital, National Cancer Center, Goyang, 10408, South Korea
| | - Dae Kyung Sohn
- Innovative Medical Engineering & Technology, Division of Convergence Technology, Research Institute and Hospital, National Cancer Center, Goyang, 10408, South Korea
| | - Jae-Heon Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Hongki Yoo
- Department of Biomedical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Bomi Gweon
- Department of Biomedical Engineering, Hanyang University, Seoul 04763, South Korea
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27
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NAD(P)H Oxidase Activity in the Small Intestine Is Predominantly Found in Enterocytes, Not Professional Phagocytes. Int J Mol Sci 2018; 19:ijms19051365. [PMID: 29734661 PMCID: PMC5983677 DOI: 10.3390/ijms19051365] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/10/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022] Open
Abstract
The balance between various cellular subsets of the innate and adaptive immune system and microbiota in the gastrointestinal tract is carefully regulated to maintain tolerance to the normal flora and dietary antigens, while protecting against pathogens. The intestinal epithelial cells and the network of dendritic cells and macrophages in the lamina propria are crucial lines of defense that regulate this balance. The complex relationship between the myeloid compartment (dendritic cells and macrophages) and lymphocyte compartment (T cells and innate lymphoid cells), as well as the impact of the epithelial cell layer have been studied in depth in recent years, revealing that the regulatory and effector functions of both innate and adaptive immune compartments exhibit more plasticity than had been previously appreciated. However, little is known about the metabolic activity of these cellular compartments, which is the basic function underlying all other additional tasks the cells perform. Here we perform intravital NAD(P)H fluorescence lifetime imaging in the small intestine of fluorescent reporter mice to monitor the NAD(P)H-dependent metabolism of epithelial and myeloid cells. The majority of myeloid cells which comprise the surveilling network in the lamina propria have a low metabolic activity and remain resting even upon stimulation. Only a few myeloid cells, typically localized at the tip of the villi, are metabolically active and are able to activate NADPH oxidases upon stimulation, leading to an oxidative burst. In contrast, the epithelial cells are metabolically highly active and, although not considered professional phagocytes, are also able to activate NADPH oxidases, leading to massive production of reactive oxygen species. Whereas the oxidative burst in myeloid cells is mainly catalyzed by the NOX2 isotype, in epithelial cells other isotypes of the NADPH oxidases family are involved, especially NOX4. They are constitutively expressed by the epithelial cells, but activated only on demand to ensure rapid defense against pathogens. This minimizes the potential for inadvertent damage from resting NOX activation, while maintaining the capacity to respond quickly if needed.
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28
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Le Marois A, Suhling K. Quantitative Live Cell FLIM Imaging in Three Dimensions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1035:31-48. [PMID: 29080129 DOI: 10.1007/978-3-319-67358-5_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In this chapter, the concept of fluorescence lifetime and its utility in quantitative live cell imaging will be introduced, along with methods to record and analyze FLIM data. Relevant applications in 3D tissue and live cell imaging, including multiplexed FLIM detection, will also be detailed.
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Affiliation(s)
- Alix Le Marois
- Department of Physics, King's College London, Strand, London, WC2R 2LS, UK
| | - Klaus Suhling
- Department of Physics, King's College London, Strand, London, WC2R 2LS, UK.
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29
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Phasor-Based Endogenous NAD(P)H Fluorescence Lifetime Imaging Unravels Specific Enzymatic Activity of Neutrophil Granulocytes Preceding NETosis. Int J Mol Sci 2018; 19:ijms19041018. [PMID: 29596303 PMCID: PMC5979388 DOI: 10.3390/ijms19041018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/15/2018] [Accepted: 03/17/2018] [Indexed: 12/16/2022] Open
Abstract
Time-correlated single-photon counting combined with multi-photon laser scanning microscopy has proven to be a versatile tool to perform fluorescence lifetime imaging in biological samples and, thus, shed light on cellular functions, both in vitro and in vivo. Here, by means of phasor-analyzed endogenous NAD(P)H (nicotinamide adenine dinucleotide (phosphate)) fluorescence lifetime imaging, we visualize the shift in the cellular metabolism of healthy human neutrophil granulocytes during phagocytosis of Staphylococcus aureus pHrodo™ beads. We correlate this with the process of NETosis, i.e., trapping of pathogens by DNA networks. Hence, we are able to directly show the dynamics of NADPH oxidase activation and its requirement in triggering NETosis in contrast to other pathways of cell death and to decipher the dedicated spatio-temporal sequence between NADPH oxidase activation, nuclear membrane disintegration and DNA network formation. The endogenous FLIM approach presented here uniquely meets the increasing need in the field of immunology to monitor cellular metabolism as a basic mechanism of cellular and tissue functions.
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30
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Nobis M, Warren SC, Lucas MC, Murphy KJ, Herrmann D, Timpson P. Molecular mobility and activity in an intravital imaging setting - implications for cancer progression and targeting. J Cell Sci 2018; 131:131/5/jcs206995. [PMID: 29511095 DOI: 10.1242/jcs.206995] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Molecular mobility, localisation and spatiotemporal activity are at the core of cell biological processes and deregulation of these dynamic events can underpin disease development and progression. Recent advances in intravital imaging techniques in mice are providing new avenues to study real-time molecular behaviour in intact tissues within a live organism and to gain exciting insights into the intricate regulation of live cell biology at the microscale level. The monitoring of fluorescently labelled proteins and agents can be combined with autofluorescent properties of the microenvironment to provide a comprehensive snapshot of in vivo cell biology. In this Review, we summarise recent intravital microscopy approaches in mice, in processes ranging from normal development and homeostasis to disease progression and treatment in cancer, where we emphasise the utility of intravital imaging to observe dynamic and transient events in vivo We also highlight the recent integration of advanced subcellular imaging techniques into the intravital imaging pipeline, which can provide in-depth biological information beyond the single-cell level. We conclude with an outlook of ongoing developments in intravital microscopy towards imaging in humans, as well as provide an overview of the challenges the intravital imaging community currently faces and outline potential ways for overcoming these hurdles.
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Affiliation(s)
- Max Nobis
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Sean C Warren
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Morghan C Lucas
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Kendelle J Murphy
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - David Herrmann
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Paul Timpson
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
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31
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Hage CH, Leclerc P, Brevier J, Fabert M, Le Nézet C, Kudlinski A, Héliot L, Louradour F. Towards two-photon excited endogenous fluorescence lifetime imaging microendoscopy. BIOMEDICAL OPTICS EXPRESS 2018; 9:142-156. [PMID: 29359093 PMCID: PMC5772571 DOI: 10.1364/boe.9.000142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/16/2017] [Accepted: 12/04/2017] [Indexed: 05/12/2023]
Abstract
In situ fluorescence lifetime imaging microscopy (FLIM) in an endoscopic configuration of the endogenous biomarker nicotinamide adenine dinucleotide (NADH) has a great potential for malignant tissue diagnosis. Moreover, two-photon nonlinear excitation provides intrinsic optical sectioning along with enhanced imaging depth. We demonstrate, for the first time to our knowledge, nonlinear endogenous FLIM in a fibered microscope with proximal detection, applied to NADH in cultured cells, as a first step to a nonlinear endomicroscope, using a double-clad microstructured fiber with convenient fiber length (> 3 m) and excitation pulse duration (≈50 fs). Fluorescence photons are collected by the fiber inner cladding and we show that its contribution to the impulse response function (IRF), which originates from its intermodal and chromatic dispersions, is small (< 600 ps) and stable for lengths up to 8 m and allows for short lifetime measurements. We use the phasor representation as a quick visualization tool adapted to the endoscopy speed requirements.
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Affiliation(s)
- C. H. Hage
- Université de Limoges, XLIM, UMR CNRS 7252, 123 Avenue A. Thomas, 87060 Limoges, France
| | - P. Leclerc
- Université de Limoges, XLIM, UMR CNRS 7252, 123 Avenue A. Thomas, 87060 Limoges, France
| | - J. Brevier
- Université de Limoges, XLIM, UMR CNRS 7252, 123 Avenue A. Thomas, 87060 Limoges, France
| | - M. Fabert
- Université de Limoges, XLIM, UMR CNRS 7252, 123 Avenue A. Thomas, 87060 Limoges, France
| | - C. Le Nézet
- Univ. Lille, CNRS, UMR 8523 – PhLAM – Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | - A. Kudlinski
- Univ. Lille, CNRS, UMR 8523 – PhLAM – Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | - L. Héliot
- Univ. Lille, CNRS, UMR 8523 – PhLAM – Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | - F. Louradour
- Université de Limoges, XLIM, UMR CNRS 7252, 123 Avenue A. Thomas, 87060 Limoges, France
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32
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Winfree S, Hato T, Day RN. Intravital microscopy of biosensor activities and intrinsic metabolic states. Methods 2017; 128:95-104. [PMID: 28434902 PMCID: PMC5776661 DOI: 10.1016/j.ymeth.2017.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/05/2017] [Accepted: 04/18/2017] [Indexed: 01/08/2023] Open
Abstract
Intravital microscopy (IVM) is an imaging tool that is capable of detecting subcellular signaling or metabolic events as they occur in tissues in the living animal. Imaging in highly scattering biological tissues, however, is challenging because of the attenuation of signal in images acquired at increasing depths. Depth-dependent signal attenuation is the major impediment to IVM, limiting the depth from which significant data can be obtained. Therefore, making quantitative measurements by IVM requires methods that use internal calibration, or alternatively, a completely different way of evaluating the signals. Here, we describe how ratiometric imaging of genetically encoded biosensor probes can be used to make quantitative measurements of changes in the activity of cell signaling pathways. Then, we describe how fluorescence lifetime imaging can be used for label-free measurements of the metabolic states of cells within the living animal.
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Affiliation(s)
- Seth Winfree
- Department of Medicine, Division of Nephrology, Indiana University, Indianapolis, IN, USA
| | - Takashi Hato
- Department of Medicine, Division of Nephrology, Indiana University, Indianapolis, IN, USA
| | - Richard N Day
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Dr., Indianapolis, IN 46202, USA.
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IDH3 mediates apoptosis of alveolar epithelial cells type 2 due to mitochondrial Ca 2+ uptake during hypocapnia. Cell Death Dis 2017; 8:e3005. [PMID: 28837149 PMCID: PMC5596584 DOI: 10.1038/cddis.2017.403] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 07/14/2017] [Accepted: 07/16/2017] [Indexed: 01/25/2023]
Abstract
In adult respiratory distress syndrome (ARDS) pulmonary perfusion failure increases physiologic dead-space (VD/VT) correlating with mortality. High VD/VT results in alveolar hypocapnia, which has been demonstrated to cause edema formation, atelectasis, and surfactant depletion, evoked, at least in part, by apoptosis of alveolar epithelial cells (AEC). However, the mechanism underlying the hypocapnia-induced AEC apoptosis is unknown. Here, using fluorescent live-cell imaging of cultured AEC type 2 we could show that in terms of CO2 sensing the tricarboxylic acid cycle enzyme isocitrate dehydrogenase (IDH) 3 seems to be an important player because hypocapnia resulted independently from pH in an elevation of IDH3 activity and subsequently in an increase of NADH, the substrate of the respiratory chain. As a consequence, the mitochondrial transmembrane potential (ΔΨ) rose causing a Ca2+ shift from cytosol into mitochondria, whereas the IDH3 knockdown inhibited these responses. Furthermore, the hypocapnia-induced mitochondrial Ca2+ uptake resulted in reactive oxygen species (ROS) production, and both the mitochondrial Ca2+ uptake and ROS production induced apoptosis. Accordingly, we provide evidence that in AEC type 2 hypocapnia induces elevation of IDH3 activity leading to apoptosis. This finding might give new insight into the pathogenesis of ARDS and may help to develop novel strategies to reduce tissue injury in ARDS.
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34
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Rakymzhan A, Radbruch H, Niesner RA. Quantitative Imaging of Ca 2+ by 3D-FLIM in Live Tissues. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1035:135-141. [PMID: 29080135 DOI: 10.1007/978-3-319-67358-5_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The calcium concentration within living cells is highly dynamic and, for many cell types, a reliable indicator of the functional state of the cells-both of isolated cells, but even, more important, of cells in tissue. In order to dynamically quantify intracellular calcium levels, various genetically encoded calcium sensors have been developed-the best of which are those based on Förster resonant energy transfer (FRET). Here we present a fluorescence lifetime imaging (FLIM) method to measure FRET in such a calcium sensor (TN L15) in neurons of hippocampal slices and of the brain stem of anesthetized mice. The method gives the unique opportunity to determine absolute neuronal calcium concentrations in the living organism.
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Affiliation(s)
- Asylkhan Rakymzhan
- Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Charitéplatz 1, 10117, Berlin, Germany
| | - Helena Radbruch
- Neuropathology, Charité-Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
| | - Raluca A Niesner
- Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Charitéplatz 1, 10117, Berlin, Germany. .,German Rheumatism Research Center, Charitéplatz 1, 10117, Berlin, Germany.
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35
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Sparks H, Görlitz F, Kelly DJ, Warren SC, Kellett PA, Garcia E, Dymoke-Bradshaw AKL, Hares JD, Neil MAA, Dunsby C, French PMW. Characterisation of new gated optical image intensifiers for fluorescence lifetime imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:013707. [PMID: 28147687 DOI: 10.1063/1.4973917] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report the characterisation of gated optical image intensifiers for fluorescence lifetime imaging, evaluating the performance of several different prototypes that culminate in a new design that provides improved spatial resolution conferred by the addition of a magnetic field to reduce the lateral spread of photoelectrons on their path between the photocathode and microchannel plate, and higher signal to noise ratio conferred by longer time gates. We also present a methodology to compare these systems and their capabilities, including the quantitative readouts of Förster resonant energy transfer.
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Affiliation(s)
- H Sparks
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - F Görlitz
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - D J Kelly
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - S C Warren
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - P A Kellett
- Kentech Instruments Ltd., Howbery Park, Wallingford OX10 8BD, United Kingdom
| | - E Garcia
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | | | - J D Hares
- Kentech Instruments Ltd., Howbery Park, Wallingford OX10 8BD, United Kingdom
| | - M A A Neil
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - C Dunsby
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - P M W French
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
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Three-Dimensional Tissue Models and Available Probes for Multi-Parametric Live Cell Microscopy: A Brief Overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1035:49-67. [DOI: 10.1007/978-3-319-67358-5_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Bremer D, Pache F, Günther R, Hornow J, Andresen V, Leben R, Mothes R, Zimmermann H, Brandt AU, Paul F, Hauser AE, Radbruch H, Niesner R. Longitudinal Intravital Imaging of the Retina Reveals Long-term Dynamics of Immune Infiltration and Its Effects on the Glial Network in Experimental Autoimmune Uveoretinitis, without Evident Signs of Neuronal Dysfunction in the Ganglion Cell Layer. Front Immunol 2016; 7:642. [PMID: 28066446 PMCID: PMC5179567 DOI: 10.3389/fimmu.2016.00642] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/13/2016] [Indexed: 12/12/2022] Open
Abstract
A hallmark of autoimmune retinal inflammation is the infiltration of the retina with cells of the innate and adaptive immune system, leading to detachment of the retinal layers and even to complete loss of the retinal photoreceptor layer. As the only optical system in the organism, the eye enables non-invasive longitudinal imaging studies of these local autoimmune processes and of their effects on the target tissue. Moreover, as a window to the central nervous system (CNS), the eye also reflects general neuroinflammatory processes taking place at various sites within the CNS. Histological studies in murine neuroinflammatory models, such as experimental autoimmune uveoretinitis (EAU) and experimental autoimmune encephalomyelitis, indicate that immune infiltration is initialized by effector CD4+ T cells, with the innate compartment (neutrophils, macrophages, and monocytes) contributing crucially to tissue degeneration that occurs at later phases of the disease. However, how the immune attack is orchestrated by various immune cell subsets in the retina and how the latter interact with the target tissue under in vivo conditions is still poorly understood. Our study addresses this gap with a novel approach for intravital two-photon microscopy, which enabled us to repeatedly track CD4+ T cells and LysM phagocytes during the entire course of EAU and to identify a specific radial infiltration pattern of these cells within the inflamed retina, starting from the optic nerve head. In contrast, highly motile CX3CR1+ cells display an opposite radial motility pattern, toward the optic nerve head. These inflammatory processes induce modifications of the microglial network toward an activated morphology, especially around the optic nerve head and main retinal blood vessels, but do not affect the neurons within the ganglion cell layer. Thanks to the new technology, non-invasive correlation of clinical scores of CNS-related pathologies with immune infiltrate behavior and subsequent tissue dysfunction is now possible. Hence, the new approach paves the way for deeper insights into the pathology of neuroinflammatory processes on a cellular basis, over the entire disease course.
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Affiliation(s)
- Daniel Bremer
- German Rheumatism Research Center , Berlin , Germany
| | - Florence Pache
- German Rheumatism Research Center, Berlin, Germany; NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | | - Ruth Leben
- German Rheumatism Research Center , Berlin , Germany
| | - Ronja Mothes
- German Rheumatism Research Center, Berlin, Germany; Department of Neuropathology, Charité - Universitätsmedizin, Berlin, Germany
| | - Hanna Zimmermann
- NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Alexander U Brandt
- NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Friedemann Paul
- NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Anja E Hauser
- German Rheumatism Research Center, Berlin, Germany; Immundynamics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Helena Radbruch
- Department of Neuropathology, Charité - Universitätsmedizin , Berlin , Germany
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Zhang Y, Cuyt A, Lee WS, Lo Bianco G, Wu G, Chen Y, Li DDU. Towards unsupervised fluorescence lifetime imaging using low dimensional variable projection. OPTICS EXPRESS 2016; 24:26777-26791. [PMID: 27857408 DOI: 10.1364/oe.24.026777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Analyzing large fluorescence lifetime imaging (FLIM) data is becoming overwhelming; the latest FLIM systems easily produce massive amounts of data, making an efficient analysis more challenging than ever. In this paper we propose the combination of a custom-fit variable projection method, with a Laguerre expansion based deconvolution, to analyze bi-exponential data obtained from time-domain FLIM systems. Unlike nonlinear least squares methods, which require a suitable initial guess from an experienced researcher, the new method is free from manual interventions and hence can support automated analysis. Monte Carlo simulations are carried out on synthesized FLIM data to demonstrate the performance compared to other approaches. The performance is also illustrated on real-life FLIM data obtained from the study of autofluorescence of daisy pollen and the endocytosis of gold nanorods (GNRs) in living cells. In the latter, the fluorescence lifetimes of the GNRs are much shorter than the full width at half maximum of the instrument response function. Overall, our proposed method contains simple steps and shows great promise in realising automated FLIM analysis of large data sets.
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Zhang Y, Chen Y, Li DDU. Optimizing Laguerre expansion based deconvolution methods for analysing bi-exponential fluorescence lifetime images. OPTICS EXPRESS 2016; 24:13894-905. [PMID: 27410552 DOI: 10.1364/oe.24.013894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Fast deconvolution is an essential step to calibrate instrument responses in big fluorescence lifetime imaging microscopy (FLIM) image analysis. This paper examined a computationally effective least squares deconvolution method based on Laguerre expansion (LSD-LE), recently developed for clinical diagnosis applications, and proposed new criteria for selecting Laguerre basis functions (LBFs) without considering the mutual orthonormalities between LBFs. Compared with the previously reported LSD-LE, the improved LSD-LE allows to use a higher laser repetition rate, reducing the acquisition time per measurement. Moreover, we extended it, for the first time, to analyze bi-exponential fluorescence decays for more general FLIM-FRET applications. The proposed method was tested on both synthesized bi-exponential and realistic FLIM data for studying the endocytosis of gold nanorods in Hek293 cells. Compared with the previously reported constrained LSD-LE, it shows promising results.
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Yu H, Saleeb R, Dalgarno P, Day-Uei Li D. Estimation of Fluorescence Lifetimes Via Rotational Invariance Techniques. IEEE Trans Biomed Eng 2016; 63:1292-300. [DOI: 10.1109/tbme.2015.2491364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Radbruch H, Bremer D, Guenther R, Cseresnyes Z, Lindquist R, Hauser AE, Niesner R. Ongoing Oxidative Stress Causes Subclinical Neuronal Dysfunction in the Recovery Phase of EAE. Front Immunol 2016; 7:92. [PMID: 27014271 DOI: 10.3389/fimmu.2016.00092] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 02/25/2016] [Indexed: 11/13/2022] Open
Abstract
Most multiple sclerosis (MS) patients develop over time a secondary progressive disease course, characterized histologically by axonal loss and atrophy. In early phases of the disease, focal inflammatory demyelination leads to functional impairment, but the mechanism of chronic progression in MS is still under debate. Reactive oxygen species generated by invading and resident central nervous system (CNS) macrophages have been implicated in mediating demyelination and axonal damage, but demyelination and neurodegeneration proceed even in the absence of obvious immune cell infiltration, during clinical recovery in chronic MS. Here, we employ intravital NAD(P)H fluorescence lifetime imaging to detect functional NADPH oxidases (NOX1-4, DUOX1, 2) and, thus, to identify the cellular source of oxidative stress in the CNS of mice affected by experimental autoimmune encephalomyelitis (EAE) in the remission phase of the disease. This directly affects neuronal function in vivo, as monitored by cellular calcium levels using intravital FRET-FLIM, providing a possible mechanism of disease progression in MS.
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Affiliation(s)
- Helena Radbruch
- Department of Neuropathology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Daniel Bremer
- German Rheumatism Research Center (DRFZ) a Leibniz Institute , Berlin , Germany
| | - Robert Guenther
- German Rheumatism Research Center (DRFZ) a Leibniz Institute , Berlin , Germany
| | - Zoltan Cseresnyes
- German Rheumatism Research Center (DRFZ) a Leibniz Institute , Berlin , Germany
| | - Randall Lindquist
- German Rheumatism Research Center (DRFZ) a Leibniz Institute , Berlin , Germany
| | - Anja E Hauser
- German Rheumatism Research Center (DRFZ) a Leibniz Institute, Berlin, Germany; Immundynamics, Charité - Universiätsmedizin Berlin, Berlin, Germany
| | - Raluca Niesner
- German Rheumatism Research Center (DRFZ) a Leibniz Institute , Berlin , Germany
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Mossakowski AA, Pohlan J, Bremer D, Lindquist R, Millward JM, Bock M, Pollok K, Mothes R, Viohl L, Radbruch M, Gerhard J, Bellmann-Strobl J, Behrens J, Infante-Duarte C, Mähler A, Boschmann M, Rinnenthal JL, Füchtemeier M, Herz J, Pache FC, Bardua M, Priller J, Hauser AE, Paul F, Niesner R, Radbruch H. Tracking CNS and systemic sources of oxidative stress during the course of chronic neuroinflammation. Acta Neuropathol 2015; 130:799-814. [PMID: 26521072 PMCID: PMC4654749 DOI: 10.1007/s00401-015-1497-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 10/15/2015] [Accepted: 10/15/2015] [Indexed: 11/30/2022]
Abstract
The functional dynamics and cellular sources of oxidative stress are central to understanding MS pathogenesis but remain elusive, due to the lack of appropriate detection methods. Here we employ NAD(P)H fluorescence lifetime imaging to detect functional NADPH oxidases (NOX enzymes) in vivo to identify inflammatory monocytes, activated microglia, and astrocytes expressing NOX1 as major cellular sources of oxidative stress in the central nervous system of mice affected by experimental autoimmune encephalomyelitis (EAE). This directly affects neuronal function in vivo, indicated by sustained elevated neuronal calcium. The systemic involvement of oxidative stress is mirrored by overactivation of NOX enzymes in peripheral CD11b+ cells in later phases of both MS and EAE. This effect is antagonized by systemic intake of the NOX inhibitor and anti-oxidant epigallocatechin-3-gallate. Together, this persistent hyper-activation of oxidative enzymes suggests an “oxidative stress memory” both in the periphery and CNS compartments, in chronic neuroinflammation.
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Affiliation(s)
- Agata A Mossakowski
- German Rheumatism Research Center, Berlin, Germany
- Department of Neurology, NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Julian Pohlan
- German Rheumatism Research Center, Berlin, Germany
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Intravital Imaging and Immune Dynamics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | | | - Jason M Millward
- Institute for Medical Immunology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Markus Bock
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karolin Pollok
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Intravital Imaging and Immune Dynamics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ronja Mothes
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Intravital Imaging and Immune Dynamics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Leonard Viohl
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Intravital Imaging and Immune Dynamics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Moritz Radbruch
- German Rheumatism Research Center, Berlin, Germany
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Judith Bellmann-Strobl
- Department of Neurology, NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Janina Behrens
- Department of Neurology, NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Carmen Infante-Duarte
- Institute for Medical Immunology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anja Mähler
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Boschmann
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jan Leo Rinnenthal
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Josephine Herz
- Department of Paediatrics I, Neonatology, University Hospital Essen, Essen, 45122, Germany
| | - Florence C Pache
- German Rheumatism Research Center, Berlin, Germany
- Department of Neurology, NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Intravital Imaging and Immune Dynamics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Josef Priller
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry, Charité-Universitätsmedizin Berlin, Cluster of Excellence NeuroCure and BIH, Berlin, Germany
| | - Anja E Hauser
- German Rheumatism Research Center, Berlin, Germany
- Intravital Imaging and Immune Dynamics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Friedemann Paul
- Department of Neurology, NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Helena Radbruch
- Institut für Neuropathologie, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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Hochreiter B, Garcia AP, Schmid JA. Fluorescent proteins as genetically encoded FRET biosensors in life sciences. SENSORS 2015; 15:26281-314. [PMID: 26501285 PMCID: PMC4634415 DOI: 10.3390/s151026281] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/08/2015] [Indexed: 12/11/2022]
Abstract
Fluorescence- or Förster resonance energy transfer (FRET) is a measurable physical energy transfer phenomenon between appropriate chromophores, when they are in sufficient proximity, usually within 10 nm. This feature has made them incredibly useful tools for many biomedical studies on molecular interactions. Furthermore, this principle is increasingly exploited for the design of biosensors, where two chromophores are linked with a sensory domain controlling their distance and thus the degree of FRET. The versatility of these FRET-biosensors made it possible to assess a vast amount of biological variables in a fast and standardized manner, allowing not only high-throughput studies but also sub-cellular measurements of biological processes. In this review, we aim at giving an overview over the recent advances in genetically encoded, fluorescent-protein based FRET-biosensors, as these represent the largest and most vividly growing group of FRET-based sensors. For easy understanding, we are grouping them into four categories, depending on their molecular mechanism. These are based on: (a) cleavage; (b) conformational-change; (c) mechanical force and (d) changes in the micro-environment. We also address the many issues and considerations that come with the development of FRET-based biosensors, as well as the possibilities that are available to measure them.
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Affiliation(s)
- Bernhard Hochreiter
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
| | - Alan Pardo Garcia
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
| | - Johannes A Schmid
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
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Krstajić N, Poland S, Levitt J, Walker R, Erdogan A, Ameer-Beg S, Henderson RK. 0.5 billion events per second time correlated single photon counting using CMOS SPAD arrays. OPTICS LETTERS 2015; 40:4305-8. [PMID: 26371922 DOI: 10.1364/ol.40.004305] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a digital architecture for fast acquisition of time correlated single photon counting (TCSPC) events from a 32×32 complementary metal oxide semiconductor (CMOS) single photon avalanche detector (SPAD) array (Megaframe) to the computer memory. Custom firmware was written to transmit event codes from 1024-TCSPC-enabled pixels for fast transfer of TCSPC events. Our 1024-channel TCSPC system is capable of acquiring up to 0.5×10(9) TCSPC events per second with 16 histogram bins spanning a 14 ns width. Other options include 320×10(6) TCSPC events per second with 256 histogram bins spanning either a 14 or 56 ns time window. We present a wide-field fluorescence microscopy setup demonstrating fast fluorescence lifetime data acquisition. To the best of our knowledge, this is the fastest direct TCSPC transfer from a single photon counting device to the computer to date.
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Tao W, Rubart M, Ryan J, Xiao X, Qiao C, Hato T, Davidson MW, Dunn KW, Day RN. A practical method for monitoring FRET-based biosensors in living animals using two-photon microscopy. Am J Physiol Cell Physiol 2015; 309:C724-35. [PMID: 26333599 DOI: 10.1152/ajpcell.00182.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/25/2015] [Indexed: 01/07/2023]
Abstract
The commercial availability of multiphoton microscope systems has nurtured the growth of intravital microscopy as a powerful technique for evaluating cell biology in the relevant context of living animals. In parallel, new fluorescent protein (FP) biosensors have become available that enable studies of the function of a wide range of proteins in living cells. Biosensor probes that exploit Förster resonance energy transfer (FRET) are among the most sensitive indicators of an array of cellular processes. However, differences between one-photon and two-photon excitation (2PE) microscopy are such that measuring FRET by 2PE in the intravital setting remains challenging. Here, we describe an approach that simplifies the use of FRET-based biosensors in intravital 2PE microscopy. Based on a systematic comparison of many different FPs, we identified the monomeric (m) FPs mTurquoise and mVenus as particularly well suited for intravital 2PE FRET studies, enabling the ratiometric measurements from linked FRET probes using a pair of experimental images collected simultaneously. The behavior of the FPs is validated by fluorescence lifetime and sensitized emission measurements of a set of FRET standards. The approach is demonstrated using a modified version of the AKAR protein kinase A biosensor, first in cells in culture, and then in hepatocytes in the liver of living mice. The approach is compatible with the most common 2PE microscope configurations and should be applicable to a variety of different FRET probes.
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Affiliation(s)
- Wen Tao
- Department of Medicine, Division of Nephrology, Indiana University Medical Center, Indianapolis, Indiana
| | - Michael Rubart
- Riley Heart Research Center, Wells Center for Pediatric Research, and Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jennifer Ryan
- Department of Medicine, Division of Nephrology, Indiana University Medical Center, Indianapolis, Indiana
| | - Xiao Xiao
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
| | - Chunping Qiao
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
| | - Takashi Hato
- Department of Medicine, Division of Nephrology, Indiana University Medical Center, Indianapolis, Indiana
| | - Michael W Davidson
- National High Magnetic Field Laboratory and Department of Biological Science, The Florida State University, Tallahassee, Florida
| | - Kenneth W Dunn
- Department of Medicine, Division of Nephrology, Indiana University Medical Center, Indianapolis, Indiana
| | - Richard N Day
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana
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van Unen J, Woolard J, Rinken A, Hoffmann C, Hill SJ, Goedhart J, Bruchas MR, Bouvier M, Adjobo-Hermans MJW. A Perspective on Studying G-Protein-Coupled Receptor Signaling with Resonance Energy Transfer Biosensors in Living Organisms. Mol Pharmacol 2015; 88:589-95. [PMID: 25972446 PMCID: PMC4551049 DOI: 10.1124/mol.115.098897] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/13/2015] [Indexed: 01/09/2023] Open
Abstract
The last frontier for a complete understanding of G-protein-coupled receptor (GPCR) biology is to be able to assess GPCR activity, interactions, and signaling in vivo, in real time within biologically intact systems. This includes the ability to detect GPCR activity, trafficking, dimerization, protein-protein interactions, second messenger production, and downstream signaling events with high spatial resolution and fast kinetic readouts. Resonance energy transfer (RET)-based biosensors allow for all of these possibilities in vitro and in cell-based assays, but moving RET into intact animals has proven difficult. Here, we provide perspectives on the optimization of biosensor design, of signal detection in living organisms, and the multidisciplinary development of in vitro and cell-based assays that more appropriately reflect the physiologic situation. In short, further development of RET-based probes, optical microscopy techniques, and mouse genome editing hold great potential over the next decade to bring real-time in vivo GPCR imaging to the forefront of pharmacology.
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Affiliation(s)
- Jakobus van Unen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Jeanette Woolard
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Ago Rinken
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Carsten Hoffmann
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Stephen J Hill
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Joachim Goedhart
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Michael R Bruchas
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Michel Bouvier
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Merel J W Adjobo-Hermans
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
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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: 2.2] [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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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: 0.7] [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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Krstajić N, Levitt J, Poland S, Ameer-Beg S, Henderson R. 256 × 2 SPAD line sensor for time resolved fluorescence spectroscopy. OPTICS EXPRESS 2015; 23:5653-69. [PMID: 25836796 DOI: 10.1364/oe.23.005653] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We present a CMOS chip 256 × 2 single photon avalanche diode (SPAD) line sensor, 23.78 µm pitch, 43.7% fill factor, custom designed for time resolved emission spectroscopy (TRES). Integrating time-to-digital converters (TDCs) implement on-chip mono-exponential fluorescence lifetime pre-calculation allowing timing of 65k photons/pixel at 200 Hz line rate at 40 ps resolution using centre-of-mass method (CMM). Per pixel time-correlated single-photon counting (TCSPC) histograms can also be generated with 320 ps bin resolution. We characterize performance in terms of dark count rate, instrument response function and lifetime uniformity for a set of fluorophores with lifetimes ranging from 4 ns to 6 ns. Lastly, we present fluorescence lifetime spectra of multicolor microspheres and skin autofluorescence acquired using a custom built spectrometer. In TCSPC mode, time-resolved spectra are acquired within 5 minutes whilst in CMM mode spectral lifetime signatures are acquired within 2 ms for fluorophore in cuvette and 200 ms for skin autofluorescence. We demonstrate CMOS line sensors to be a versatile tool for time-resolved fluorescence spectroscopy by providing parallelized and flexible spectral detection of fluorescence decay.
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