1
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Fluorophore spectroscopy in aqueous glycerol solution: the interactions of glycerol with the fluorophore. Photochem Photobiol Sci 2021; 20:1397-1418. [PMID: 34609728 DOI: 10.1007/s43630-021-00096-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/24/2021] [Indexed: 10/20/2022]
Abstract
A common perception exists that glycerol provides an inert-like environment modifying viscosity and index of refraction by its various concentrations in aqueous solution. Said perception is herein challenged by investigating the effects of the glycerol environment on the spectroscopic properties of fluorescein, as a representative fluorophore, using steady-state and time-resolved techniques and computational chemistry. Results strongly suggest that the fluorescence quantum yield, measured fluorescence lifetime (FLT), natural lifetime and calculated fluorescence lifetime are all highly sensitive to the presence of glycerol. Glycerol was found to impact both the ground and first excited states of fluorescein, quenching and modifying both absorption and emission spectra, affecting the fundamental electrical dipoles of the ground and first excited singlet states, and lowering FLT and quantum yield. Furthermore, the Stern-Volmer, Lippert-Mataga, Perrin and Strickler-Berg relations indicate that glycerol acts upon fluorescein in aqueous solution as a quencher and alters the fluorescein geometry. Predictions made by computational chemistry impressively correspond to experimental results, both indicating changes in the properties of fluorescein at around 35% v/v aqueous glycerol, a clear indication that glycerol is not an innocent medium. This study proposes the Strickler-Berg relation as a means of detecting non-negligible effects of a hosting medium on its host fluorophore. These new insights on the molecular structures, the interactions between glycerol and its host fluorophore, and the effects of one on the other may be essential for understanding fundamental phenomena in chemistry and related fields.
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2
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Laskaratou D, Fernández GS, Coucke Q, Fron E, Rocha S, Hofkens J, Hendrix J, Mizuno H. Quantification of FRET-induced angular displacement by monitoring sensitized acceptor anisotropy using a dim fluorescent donor. Nat Commun 2021; 12:2541. [PMID: 33953187 PMCID: PMC8099864 DOI: 10.1038/s41467-021-22816-7] [Citation(s) in RCA: 8] [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] [Received: 09/18/2020] [Accepted: 03/23/2021] [Indexed: 02/03/2023] Open
Abstract
Förster resonance energy transfer (FRET) between fluorescent proteins has become a common platform for designing genetically encoded biosensors. For live cell imaging, the acceptor-to-donor intensity ratio is most commonly used to readout FRET efficiency, which largely depends on the proximity between donor and acceptor. Here, we introduce an anisotropy-based mode of FRET detection (FADED: FRET-induced Angular Displacement Evaluation via Dim donor), which probes for relative orientation rather than proximity alteration. A key element in this technique is suppression of donor bleed-through, which allows measuring purer sensitized acceptor anisotropy. This is achieved by developing Geuda Sapphire, a low-quantum-yield FRET-competent fluorescent protein donor. As a proof of principle, Ca2+ sensors were designed using calmodulin as a sensing domain, showing sigmoidal dose response to Ca2+. By monitoring the anisotropy, a Ca2+ rise in living HeLa cells is observed upon histamine challenging. We conclude that FADED provides a method for quantifying the angular displacement via FRET.
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Affiliation(s)
- Danai Laskaratou
- Laboratory for Biomolecular Network Dynamics, Biochemistry, Molecular and Structural Biology Section, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | | | - Quinten Coucke
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | - Eduard Fron
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
- KU Leuven Core Facility for Advanced Spectroscopy, KU Leuven, Heverlee, Belgium
| | - Susana Rocha
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | - Johan Hofkens
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | - Jelle Hendrix
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and Biomedical Research Institute, Hasselt University, Agoralaan C (BIOMED), Diepenbeek, Belgium
| | - Hideaki Mizuno
- Laboratory for Biomolecular Network Dynamics, Biochemistry, Molecular and Structural Biology Section, Department of Chemistry, KU Leuven, Heverlee, Belgium.
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3
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Time-Resolved Fluorescence Anisotropy and Molecular Dynamics Analysis of a Novel GFP Homo-FRET Dimer. Biophys J 2020; 120:254-269. [PMID: 33345902 PMCID: PMC7840444 DOI: 10.1016/j.bpj.2020.11.2275] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/06/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023] Open
Abstract
Förster resonance energy transfer (FRET) is a powerful tool to investigate the interaction between proteins in living cells. Fluorescence proteins, such as the green fluorescent protein (GFP) and its derivatives, are coexpressed in cells linked to proteins of interest. Time-resolved fluorescence anisotropy is a popular tool to study homo-FRET of fluorescent proteins as an indicator of dimerization, in which its signature consists of a very short component at the beginning of the anisotropy decay. In this work, we present an approach to study GFP homo-FRET via a combination of time-resolved fluorescence anisotropy, the stretched exponential decay model, and molecular dynamics simulations. We characterize a new, to our knowledge, FRET standard formed by two enhanced GFPs (eGFPs) and a flexible linker of 15 aminoacids (eGFP15eGFP) with this protocol, which is validated by using an eGFP monomer as a reference. An excellent agreement is found between the FRET efficiency calculated from the fit of the eGFP15eGFP fluorescence anisotropy decays with a stretched exponential decay model (〈EFRETexp〉 = 0.25 ± 0.05) and those calculated from the molecular dynamics simulations (〈EFRETMD〉 = 0.18 ± 0.14). The relative dipole orientation between the GFPs is best described by the orientation factors 〈κ2〉 = 0.17 ± 0.16 and 〈|κ|〉 = 0.35 ± 0.20, contextualized within a static framework in which the linker hinders the free rotation of the fluorophores and excludes certain configurations. The combination of time- and polarization-resolved fluorescence spectroscopy with molecular dynamics simulations is shown to be a powerful tool for the study and interpretation of homo-FRET.
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4
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Coelho S, Poland SP, Devauges V, Ameer-Beg SM. Adaptive optics for a time-resolved Förster resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM) in vivo. OPTICS LETTERS 2020; 45:2732-2735. [PMID: 32412453 PMCID: PMC7340371 DOI: 10.1364/ol.385950] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 06/11/2023]
Abstract
Förster resonance energy transfer (FRET) and fluorescence lifetime imaging (FLIM) have been coupled with multiphoton microscopy to image in vivo dynamics. However, the increase in optical aberrations as a function of depth significantly reduces the fluorescent signal, spatial resolution, and fluorescence lifetime accuracy. We present the development of a time-resolved FRET-FLIM imaging system with adaptive optics. We demonstrate the improvement of our adaptive optics (AO)-FRET-FLIM instrument over standard multiphoton FRET-FLIM imaging. We validate our approach using fixed cellular samples with FRET standards and in vivo with live imaging in a mouse kidney.
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Affiliation(s)
- Simao Coelho
- Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, Guy’s Campus, King’s College London, London, UK
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Simon P. Poland
- Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, Guy’s Campus, King’s College London, London, UK
| | - Viviane Devauges
- Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, Guy’s Campus, King’s College London, London, UK
| | - Simon M. Ameer-Beg
- Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, Guy’s Campus, King’s College London, London, UK
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5
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Jain P, Boso G, Langer S, Soonthornvacharin S, De Jesus PD, Nguyen Q, Olivieri KC, Portillo AJ, Yoh SM, Pache L, Chanda SK. Large-Scale Arrayed Analysis of Protein Degradation Reveals Cellular Targets for HIV-1 Vpu. Cell Rep 2018; 22:2493-2503. [PMID: 29490283 PMCID: PMC5916846 DOI: 10.1016/j.celrep.2018.01.091] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 11/03/2017] [Accepted: 01/30/2018] [Indexed: 11/28/2022] Open
Abstract
Accessory proteins of lentiviruses, such as HIV-1, target cellular restriction factors to enhance viral replication. Systematic analyses of proteins that are targeted for degradation by HIV-1 accessory proteins may provide a better understanding of viral immune evasion strategies. Here, we describe a high-throughput platform developed to study cellular protein stability in a highly parallelized matrix format. We used this approach to identify cellular targets of the HIV-1 accessory protein Vpu through arrayed coexpression with 433 interferon-stimulated genes, followed by differential fluorescent labeling and automated image analysis. Among the previously unreported Vpu targets identified by this approach, we find that the E2 ligase mediating ISG15 conjugation, UBE2L6, and the transmembrane protein PLP2 are targeted by Vpu during HIV-1 infection to facilitate late-stage replication. This study provides a framework for the systematic and high-throughput evaluation of protein stability and establishes a more comprehensive portrait of cellular Vpu targets.
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Affiliation(s)
- Prashant Jain
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Guney Boso
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Simon Langer
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Stephen Soonthornvacharin
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Paul D De Jesus
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Quy Nguyen
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Kevin C Olivieri
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Alex J Portillo
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Sunnie M Yoh
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lars Pache
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
| | - Sumit K Chanda
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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6
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Zhu B, Jiang L, Huang T, Zhao Y, Liu T, Zhong Y, Li X, Campos A, Pomeroy K, Masliah E, Zhang D, Xu H. ER-associated degradation regulates Alzheimer's amyloid pathology and memory function by modulating γ-secretase activity. Nat Commun 2017; 8:1472. [PMID: 29133892 PMCID: PMC5684335 DOI: 10.1038/s41467-017-01799-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022] Open
Abstract
Endoplasmic-reticulum-associated degradation (ERAD) is an important protein quality control system which maintains protein homeostasis. Constituents of the ERAD complex and its role in neurodegeneration are not yet fully understood. Here, using proteomic and FRET analyses, we demonstrate that the ER protein membralin is an ERAD component, which mediates degradation of ER luminal and membrane substrates. Interestingly, we identify nicastrin, a key component of the γ-secretase complex, as a membralin binding protein and membralin-associated ERAD substrate. We demonstrate a reduction of membralin mRNA and protein levels in Alzheimer's disease (AD) brain, the latter of which inversely correlates with nicastrin abundance. Furthermore, membralin deficiency enhances γ-secretase activity and neuronal degeneration. In a mouse AD model, downregulating membralin results in β-amyloid pathology, neuronal death, and exacerbates synaptic/memory deficits. Our results identify membralin as an ERAD component and demonstrate a critical role for ERAD in AD pathogenesis.
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Affiliation(s)
- Bing Zhu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - LuLin Jiang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Timothy Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yingjun Zhao
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Tongfei Liu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yongwang Zhong
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Xiaoguang Li
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Alexandre Campos
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Kenneth Pomeroy
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Eliezer Masliah
- Departments of Neurosciences and Pathology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Dongxian Zhang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Huaxi Xu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, 361005, Fujian, China.
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7
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Görlitz F, Kelly DJ, Warren SC, Alibhai D, West L, Kumar S, Alexandrov Y, Munro I, Garcia E, McGinty J, Talbot C, Serwa RA, Thinon E, da Paola V, Murray EJ, Stuhmeier F, Neil MAA, Tate EW, Dunsby C, French PMW. Open Source High Content Analysis Utilizing Automated Fluorescence Lifetime Imaging Microscopy. J Vis Exp 2017:55119. [PMID: 28190060 PMCID: PMC5352269 DOI: 10.3791/55119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We present an open source high content analysis instrument utilizing automated fluorescence lifetime imaging (FLIM) for assaying protein interactions using Förster resonance energy transfer (FRET) based readouts of fixed or live cells in multiwell plates. This provides a means to screen for cell signaling processes read out using intramolecular FRET biosensors or intermolecular FRET of protein interactions such as oligomerization or heterodimerization, which can be used to identify binding partners. We describe here the functionality of this automated multiwell plate FLIM instrumentation and present exemplar data from our studies of HIV Gag protein oligomerization and a time course of a FRET biosensor in live cells. A detailed description of the practical implementation is then provided with reference to a list of hardware components and a description of the open source data acquisition software written in µManager. The application of FLIMfit, an open source MATLAB-based client for the OMERO platform, to analyze arrays of multiwell plate FLIM data is also presented. The protocols for imaging fixed and live cells are outlined and a demonstration of an automated multiwell plate FLIM experiment using cells expressing fluorescent protein-based FRET constructs is presented. This is complemented by a walk-through of the data analysis for this specific FLIM FRET data set.
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Affiliation(s)
- Frederik Görlitz
- Photonics Group, Department of Physics, Imperial College London;
| | - Douglas J Kelly
- Photonics Group, Department of Physics, Imperial College London
| | - Sean C Warren
- Photonics Group, Department of Physics, Imperial College London
| | - Dominic Alibhai
- Institute for Chemical Biology, Department of Chemistry, Imperial College London
| | - Lucien West
- MRC Clinical Sciences Centre, Hammersmith Hospital
| | - Sunil Kumar
- Photonics Group, Department of Physics, Imperial College London
| | | | - Ian Munro
- Photonics Group, Department of Physics, Imperial College London
| | - Edwin Garcia
- Photonics Group, Department of Physics, Imperial College London
| | - James McGinty
- Photonics Group, Department of Physics, Imperial College London
| | - Clifford Talbot
- Photonics Group, Department of Physics, Imperial College London
| | - Remigiusz A Serwa
- Chemical Biology Section, Department of Chemistry, Imperial College London
| | - Emmanuelle Thinon
- Chemical Biology Section, Department of Chemistry, Imperial College London
| | | | | | - Frank Stuhmeier
- Pfizer Global Research and Development, Pfizer Limited, Sandwich, Kent, UK
| | - Mark A A Neil
- Photonics Group, Department of Physics, Imperial College London
| | - Edward W Tate
- Chemical Biology Section, Department of Chemistry, Imperial College London
| | - Christopher Dunsby
- Photonics Group, Department of Physics, Imperial College London; Centre for Histopathology, Imperial College London
| | - Paul M W French
- Photonics Group, Department of Physics, Imperial College London
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8
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Margineanu A, Chan JJ, Kelly DJ, Warren SC, Flatters D, Kumar S, Katan M, Dunsby CW, French PMW. Screening for protein-protein interactions using Förster resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM). Sci Rep 2016; 6:28186. [PMID: 27339025 PMCID: PMC4919659 DOI: 10.1038/srep28186] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/19/2016] [Indexed: 11/09/2022] Open
Abstract
We present a high content multiwell plate cell-based assay approach to quantify protein interactions directly in cells using Förster resonance energy transfer (FRET) read out by automated fluorescence lifetime imaging (FLIM). Automated FLIM is implemented using wide-field time-gated detection, typically requiring only 10 s per field of view (FOV). Averaging over biological, thermal and shot noise with 100's to 1000's of FOV enables unbiased quantitative analysis with high statistical power. Plotting average donor lifetime vs. acceptor/donor intensity ratio clearly identifies protein interactions and fitting to double exponential donor decay models provides estimates of interacting population fractions that, with calibrated donor and acceptor fluorescence intensities, can yield dissociation constants. We demonstrate the application to identify binding partners of MST1 kinase and estimate interaction strength among the members of the RASSF protein family, which have important roles in apoptosis via the Hippo signalling pathway. KD values broadly agree with published biochemical measurements.
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Affiliation(s)
- Anca Margineanu
- Imperial College London, Dept. Physics, Photonics Lab., Blackett building, Prince Consort Road, London, SW7 2AZ, UK
| | - Jia Jia Chan
- University College London, Institute of Structural and Molecular Biology, Darwin building, Gower St., London, WC1E 6BT, UK
| | - Douglas J. Kelly
- Imperial College London, Dept. Physics, Photonics Lab., Blackett building, Prince Consort Road, London, SW7 2AZ, UK
- Imperial College London, Institute of Chemical Biology, London, SW7 2AZ, London, UK
| | - Sean C. Warren
- Imperial College London, Dept. Physics, Photonics Lab., Blackett building, Prince Consort Road, London, SW7 2AZ, UK
- Imperial College London, Institute of Chemical Biology, London, SW7 2AZ, London, UK
| | - Delphine Flatters
- Université Paris Diderot, Sorbonne Paris Cité, Molécules Thérapeutiques in silico, Inserm UMR-S 973, 35 rue Helene Brion, 75013 Paris, France
| | - Sunil Kumar
- Imperial College London, Dept. Physics, Photonics Lab., Blackett building, Prince Consort Road, London, SW7 2AZ, UK
| | - Matilda Katan
- University College London, Institute of Structural and Molecular Biology, Darwin building, Gower St., London, WC1E 6BT, UK
| | - Christopher W. Dunsby
- Imperial College London, Dept. Physics, Photonics Lab., Blackett building, Prince Consort Road, London, SW7 2AZ, UK
| | - Paul M. W. French
- Imperial College London, Dept. Physics, Photonics Lab., Blackett building, Prince Consort Road, London, SW7 2AZ, UK
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9
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Poland SP, Erdogan AT, Krstajić N, Levitt J, Devauges V, Walker RJ, Li DDU, Ameer-Beg SM, Henderson RK. New high-speed centre of mass method incorporating background subtraction for accurate determination of fluorescence lifetime. OPTICS EXPRESS 2016; 24:6899-915. [PMID: 27136986 DOI: 10.1364/oe.24.006899] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We demonstrate an implementation of a centre-of-mass method (CMM) incorporating background subtraction for use in multifocal fluorescence lifetime imaging microscopy to accurately determine fluorescence lifetime in live cell imaging using the Megaframe camera. The inclusion of background subtraction solves one of the major issues associated with centre-of-mass approaches, namely the sensitivity of the algorithm to background signal. The algorithm, which is predominantly implemented in hardware, provides real-time lifetime output and allows the user to effectively condense large amounts of photon data. Instead of requiring the transfer of thousands of photon arrival times, the lifetime is simply represented by one value which allows the system to collect data up to limit of pulse pile-up without any limitations on data transfer rates. In order to evaluate the performance of this new CMM algorithm with existing techniques (i.e. rapid lifetime determination and Levenburg-Marquardt), we imaged live MCF-7 human breast carcinoma cells transiently transfected with FRET standards. We show that, it offers significant advantages in terms of lifetime accuracy and insensitivity to variability in dark count rate (DCR) between Megaframe camera pixels. Unlike other algorithms no prior knowledge of the expected lifetime is required to perform lifetime determination. The ability of this technique to provide real-time lifetime readout makes it extremely useful for a number of applications.
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10
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Bullenkamp J, Gäken J, Festy F, Chong EZ, Ng T, Tavassoli M. Apoptin interacts with and regulates the activity of protein kinase C beta in cancer cells. Apoptosis 2016; 20:831-42. [PMID: 25828882 DOI: 10.1007/s10495-015-1120-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Apoptin, the VP3 protein from chicken anaemia virus (CAV), induces tumour cell-specific cell death and represents a potential future anti-cancer therapeutic. In tumour but not in normal cells, Apoptin is phosphorylated and translocates to the nucleus, enabling its cytotoxic activity. Recently, the β isozyme of protein kinase C (PKCβ) was shown to phosphorylate Apoptin in multiple myeloma cell lines. However, the exact mechanism and nature of interaction between PKCβ and Apoptin remain unclear. Here we investigated the physical and functional link between PKCβ and CAV-Apoptin as well as with the recently identified Apoptin homologue derived from human Gyrovirus (HGyV). In contrast to HCT116 colorectal cancer cells the normal colon mucosa cell lines expressed low levels of PKCβI and showed reduced Apoptin activation, as evident by cytoplasmic localisation, decreased phosphorylation and lack of cytotoxic activity. Co-immunoprecipitation and proximity ligation assay studies identified binding of both CAV- and HGyV-Apoptin to PKCβI in HCT116 cells. Using Apoptin deletion constructs the N-terminal domain of Apoptin was found to be required for interacting with PKCβI. FRET-based PKC activity reporter assays by fluorescence lifetime imaging microscopy showed that expression of Apoptin in cancer cells but not in normal cells triggers a significant increase in PKC activity. Collectively, the results demonstrate a novel cancer specific interplay between Apoptin and PKCβI. Direct interaction between the two proteins leads to Apoptin-induced activation of PKC and consequently activated PKCβI mediates phosphorylation of Apoptin to promote its tumour-specific nuclear translocation and cytotoxic function.
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Affiliation(s)
- Jessica Bullenkamp
- Department of Molecular Oncology, King's College London, Guy's Campus, Hodgkin Building, London, SE1 1UL, UK
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11
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Suzuki M, Sakata I, Sakai T, Tomioka H, Nishigaki K, Tramier M, Coppey-Moisan M. A high-throughput direct fluorescence resonance energy transfer-based assay for analyzing apoptotic proteases using flow cytometry and fluorescence lifetime measurements. Anal Biochem 2015; 491:10-7. [DOI: 10.1016/j.ab.2015.08.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/11/2015] [Accepted: 08/14/2015] [Indexed: 01/27/2023]
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12
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Levitt JA, Morton PE, Fruhwirth GO, Santis G, Chung PH, Parsons M, Suhling K. Simultaneous FRAP, FLIM and FAIM for measurements of protein mobility and interaction in living cells. BIOMEDICAL OPTICS EXPRESS 2015; 6:3842-54. [PMID: 26504635 PMCID: PMC4605044 DOI: 10.1364/boe.6.003842] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/16/2015] [Accepted: 08/18/2015] [Indexed: 05/23/2023]
Abstract
We present a novel integrated multimodal fluorescence microscopy technique for simultaneous fluorescence recovery after photobleaching (FRAP), fluorescence lifetime imaging (FLIM) and fluorescence anisotropy imaging (FAIM). This approach captures a series of polarization-resolved fluorescence lifetime images during a FRAP recovery, maximizing the information available from a limited photon budget. We have applied this method to analyse the behaviour of GFP-labelled coxsackievirus and adenovirus receptor (CAR) in living human epithelial cells. Our data reveal that CAR exists in oligomeric states throughout the cell, and that these complexes occur in conjunction with high immobile fractions of the receptor at cell-cell junctions. These findings shed light on previously unknown molecular associations between CAR receptors in intact cells and demonstrate the power of combined FRAP, FLIM and FAIM microscopy as a robust method to analyse complex multi-component dynamics in living cells.
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Affiliation(s)
- James A. Levitt
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
| | - Penny E. Morton
- Division of Asthma, Allergy, and Lung Biology, Guys Campus, King’s College London, London, UK
- Randall Division of Cell and Molecular Biophysics, Guys Campus, King’s College London, London, SE1 1UL, UK
| | - Gilbert O. Fruhwirth
- Department of Imaging Chemsitry and Biology, Division of Imaging Sciences and Biomedical Engineering, St. Thomas Hospital, King's College London, SE1 7EH, UK
| | - George Santis
- Division of Asthma, Allergy, and Lung Biology, Guys Campus, King’s College London, London, UK
| | - Pei-Hua Chung
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
| | - Maddy Parsons
- Randall Division of Cell and Molecular Biophysics, Guys Campus, King’s College London, London, SE1 1UL, UK
| | - Klaus Suhling
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
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13
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Guzmán C, Oetken-Lindholm C, Abankwa D. Automated High-Throughput Fluorescence Lifetime Imaging Microscopy to Detect Protein-Protein Interactions. ACTA ACUST UNITED AC 2015; 21:238-45. [PMID: 26384400 DOI: 10.1177/2211068215606048] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/16/2022]
Abstract
Fluorescence resonance energy transfer (FRET) is widely used to study conformational changes of macromolecules and protein-protein, protein-nucleic acid, and protein-small molecule interactions. FRET biosensors can serve as valuable secondary assays in drug discovery and for target validation in mammalian cells. Fluorescence lifetime imaging microscopy (FLIM) allows precise quantification of the FRET efficiency in intact cells, as FLIM is independent of fluorophore concentration, detection efficiency, and fluorescence intensity. We have developed an automated FLIM system using a commercial frequency domain FLIM attachment (Lambert Instruments) for wide-field imaging. Our automated FLIM system is capable of imaging and analyzing up to 50 different positions of a slide in less than 4 min, or the inner 60 wells of a 96-well plate in less than 20 min. Automation is achieved using a motorized stage and controller (Prior Scientific) coupled with a Zeiss Axio Observer body and full integration into the Lambert Instruments FLIM acquisition software. As an application example, we analyze the interaction of the oncoprotein Ras and its effector Raf after drug treatment. In conclusion, our automated FLIM imaging system requires only commercial components and may therefore allow for a broader use of this technique in chemogenomics projects.
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Affiliation(s)
- Camilo Guzmán
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | | | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
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Zhang H, Wu Q, Berezin MY. Fluorescence anisotropy (polarization): from drug screening to precision medicine. Expert Opin Drug Discov 2015; 10:1145-61. [PMID: 26289575 DOI: 10.1517/17460441.2015.1075001] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Fluorescence anisotropy (FA) is one of the major established methods accepted by industry and regulatory agencies for understanding the mechanisms of drug action and selecting drug candidates utilizing a high-throughput format. AREAS COVERED This review covers the basics of FA and complementary methods, such as fluorescence lifetime anisotropy and their roles in the drug discovery process. The authors highlight the factors affecting FA readouts, fluorophore selection and instrumentation. Furthermore, the authors describe the recent development of a successful, commercially valuable FA assay for long QT syndrome drug toxicity to illustrate the role that FA can play in the early stages of drug discovery. EXPERT OPINION Despite the success in drug discovery, the FA-based technique experiences competitive pressure from other homogeneous assays. That being said, FA is an established yet rapidly developing technique, recognized by academic institutions, the pharmaceutical industry and regulatory agencies across the globe. The technical problems encountered in working with small molecules in homogeneous assays are largely solved, and new challenges come from more complex biological molecules and nanoparticles. With that, FA will remain one of the major work-horse techniques leading to precision (personalized) medicine.
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Affiliation(s)
- Hairong Zhang
- a 1 Washington University School of Medicine, Department of Radiology , St. Louis 63110, USA
| | - Qian Wu
- a 1 Washington University School of Medicine, Department of Radiology , St. Louis 63110, USA
| | - Mikhail Y Berezin
- a 1 Washington University School of Medicine, Department of Radiology , St. Louis 63110, USA.,b 2 Washington University School of Medicine, Institute of Materials Science and Engineering, Department of Radiology , 510 S. Kingshighway, Barnard Bldg, 6th floor, 6604A, St. Louis, MO, USA +1 314 747 0701 ; +1 314 747 5191 ;
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15
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Nedbal J, Visitkul V, Ortiz-Zapater E, Weitsman G, Chana P, Matthews DR, Ng T, Ameer-Beg SM. Time-domain microfluidic fluorescence lifetime flow cytometry for high-throughput Förster resonance energy transfer screening. Cytometry A 2015; 87:104-18. [PMID: 25523156 PMCID: PMC4440390 DOI: 10.1002/cyto.a.22616] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 11/12/2014] [Accepted: 12/03/2014] [Indexed: 01/22/2023]
Abstract
Sensing ion or ligand concentrations, physico-chemical conditions, and molecular dimerization or conformation change is possible by assays involving fluorescent lifetime imaging. The inherent low throughput of imaging impedes rigorous statistical data analysis on large cell numbers. We address this limitation by developing a fluorescence lifetime-measuring flow cytometer for fast fluorescence lifetime quantification in living or fixed cell populations. The instrument combines a time-correlated single photon counting epifluorescent microscope with microfluidics cell-handling system. The associated computer software performs burst integrated fluorescence lifetime analysis to assign fluorescence lifetime, intensity, and burst duration to each passing cell. The maximum safe throughput of the instrument reaches 3,000 particles per minute. Living cells expressing spectroscopic rulers of varying peptide lengths were distinguishable by Förster resonant energy transfer measured by donor fluorescence lifetime. An epidermal growth factor (EGF)-stimulation assay demonstrated the technique's capacity to selectively quantify EGF receptor phosphorylation in cells, which was impossible by measuring sensitized emission on a standard flow cytometer. Dual-color fluorescence lifetime detection and cell-specific chemical environment sensing were exemplified using di-4-ANEPPDHQ, a lipophilic environmentally sensitive dye that exhibits changes in its fluorescence lifetime as a function of membrane lipid order. To our knowledge, this instrument opens new applications in flow cytometry which were unavailable due to technological limitations of previously reported fluorescent lifetime flow cytometers. The presented technique is sensitive to lifetimes of most popular fluorophores in the 0.5-5 ns range including fluorescent proteins and is capable of detecting multi-exponential fluorescence lifetime decays. This instrument vastly enhances the throughput of experiments involving fluorescence lifetime measurements, thereby providing statistically significant quantitative data for analysis of large cell populations. © 2014 International Society for Advancement of Cytometry.
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Affiliation(s)
- Jakub Nedbal
- Division of Cancer Studies, King's College LondonUnited Kingdom
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
| | - Viput Visitkul
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
| | - Elena Ortiz-Zapater
- Division of Asthma, Allergy & Lung Biology, King's College LondonUnited Kingdom
| | | | - Prabhjoat Chana
- Immune Monitoring Laboratory, NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College LondonUnited Kingdom
| | - Daniel R Matthews
- Queensland Brain Institute, The University of QueenslandSt Lucia, Australia
| | - Tony Ng
- Division of Cancer Studies, King's College LondonUnited Kingdom
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
- UCL Cancer Institute, University College LondonUnited Kingdom
| | - Simon M Ameer-Beg
- Division of Cancer Studies, King's College LondonUnited Kingdom
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
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16
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Devauges V, Matthews DR, Aluko J, Nedbal J, Levitt JA, Poland SP, Coban O, Weitsman G, Monypenny J, Ng T, Ameer-Beg SM. Steady-state acceptor fluorescence anisotropy imaging under evanescent excitation for visualisation of FRET at the plasma membrane. PLoS One 2014; 9:e110695. [PMID: 25360776 PMCID: PMC4215982 DOI: 10.1371/journal.pone.0110695] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/15/2014] [Indexed: 11/22/2022] Open
Abstract
We present a novel imaging system combining total internal reflection fluorescence (TIRF) microscopy with measurement of steady-state acceptor fluorescence anisotropy in order to perform live cell Förster Resonance Energy Transfer (FRET) imaging at the plasma membrane. We compare directly the imaging performance of fluorescence anisotropy resolved TIRF with epifluorescence illumination. The use of high numerical aperture objective for TIRF required correction for induced depolarization factors. This arrangement enabled visualisation of conformational changes of a Raichu-Cdc42 FRET biosensor by measurement of intramolecular FRET between eGFP and mRFP1. Higher activity of the probe was found at the cell plasma membrane compared to intracellularly. Imaging fluorescence anisotropy in TIRF allowed clear differentiation of the Raichu-Cdc42 biosensor from negative control mutants. Finally, inhibition of Cdc42 was imaged dynamically in live cells, where we show temporal changes of the activity of the Raichu-Cdc42 biosensor.
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Affiliation(s)
- Viviane Devauges
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Daniel R. Matthews
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Justin Aluko
- Department of Physics, King's College London, London, United Kingdom
| | - Jakub Nedbal
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - James A. Levitt
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Simon P. Poland
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Oana Coban
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Gregory Weitsman
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - James Monypenny
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Tony Ng
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Simon M. Ameer-Beg
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
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17
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Poland SP, Krstajić N, Coelho S, Tyndall D, Walker RJ, Devauges V, Morton PE, Nicholas NS, Richardson J, Li DDU, Suhling K, Wells CM, Parsons M, Henderson RK, Ameer-Beg SM. Time-resolved multifocal multiphoton microscope for high speed FRET imaging in vivo. OPTICS LETTERS 2014; 39:6013-6. [PMID: 25361143 DOI: 10.1364/ol.39.006013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Imaging the spatiotemporal interaction of proteins in vivo is essential to understanding the complexities of biological systems. The highest accuracy monitoring of protein-protein interactions is achieved using Förster resonance energy transfer (FRET) measured by fluorescence lifetime imaging, with measurements taking minutes to acquire a single frame, limiting their use in dynamic live cell systems. We present a diffraction limited, massively parallel, time-resolved multifocal multiphoton microscope capable of producing fluorescence lifetime images with 55 ps time-resolution, giving improvements in acquisition speed of a factor of 64. We present demonstrations with FRET imaging in a model cell system and demonstrate in vivo FLIM using a GTPase biosensor in the zebrafish embryo.
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18
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Conway JRW, Carragher NO, Timpson P. Developments in preclinical cancer imaging: innovating the discovery of therapeutics. Nat Rev Cancer 2014; 14:314-28. [PMID: 24739578 DOI: 10.1038/nrc3724] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Integrating biological imaging into early stages of the drug discovery process can provide invaluable readouts of drug activity within complex disease settings, such as cancer. Iterating this approach from initial lead compound identification in vitro to proof-of-principle in vivo analysis represents a key challenge in the drug discovery field. By embracing more complex and informative models in drug discovery, imaging can improve the fidelity and statistical robustness of preclinical cancer studies. In this Review, we highlight how combining advanced imaging with three-dimensional systems and intravital mouse models can provide more informative and disease-relevant platforms for cancer drug discovery.
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Affiliation(s)
- James R W Conway
- Garvan Institute of Medical Research and The Kinghorn Cancer Centre Sydney, St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, New South Wales 2010, Sydney, Australia
| | - Neil O Carragher
- Edinburgh Cancer Research UK Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XR, UK
| | - Paul Timpson
- Garvan Institute of Medical Research and The Kinghorn Cancer Centre Sydney, St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, New South Wales 2010, Sydney, Australia
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19
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Nobis M, Carragher NO, McGhee EJ, Morton JP, Sansom OJ, Anderson KI, Timpson P. Advanced intravital subcellular imaging reveals vital three-dimensional signalling events driving cancer cell behaviour and drug responses in live tissue. FEBS J 2013; 280:5177-97. [PMID: 23678945 DOI: 10.1111/febs.12348] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/13/2013] [Accepted: 05/14/2013] [Indexed: 12/18/2022]
Abstract
The integration of signal transduction pathways plays a fundamental role in governing disease initiation, progression and outcome. It is therefore necessary to understand disease at the signalling level to enable effective treatment and to intervene in its progression. The recent extension of in vitro subcellular image-based analysis to live in vivo modelling of disease is providing a more complete picture of real-time, dynamic signalling processes or drug responses in live tissue. Intravital imaging offers alternative strategies for studying disease and embraces the biological complexities that govern disease progression. In the present review, we highlight how three-dimensional or live intravital imaging has uncovered novel insights into biological mechanisms or modes of drug action. Furthermore, we offer a prospective view of how imaging applications may be integrated further with the aim of understanding disease in a more physiological and functional manner within the framework of the drug discovery process.
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Affiliation(s)
- Max Nobis
- The Beatson Institute for Cancer Research, Glasgow, UK
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20
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BARBER PR, TULLIS IDC, PIERCE GP, NEWMAN RG, PRENTICE J, ROWLEY MI, MATTHEWS DR, AMEER-BEG SM, VOJNOVIC B. The Gray Institute 'open' high-content, fluorescence lifetime microscopes. J Microsc 2013; 251:154-67. [PMID: 23772985 PMCID: PMC3910159 DOI: 10.1111/jmi.12057] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 05/09/2013] [Indexed: 01/07/2023]
Abstract
We describe a microscopy design methodology and details of microscopes built to this 'open' design approach. These demonstrate the first implementation of time-domain fluorescence microscopy in a flexible automated platform with the ability to ease the transition of this and other advanced microscopy techniques from development to use in routine biology applications. This approach allows easy expansion and modification of the platform capabilities, as it moves away from the use of a commercial, monolithic, microscope body to small, commercial off-the-shelf and custom made modular components. Drawings and diagrams of our microscopes have been made available under an open license for noncommercial use at http://users.ox.ac.uk/~atdgroup. Several automated high-content fluorescence microscope implementations have been constructed with this design framework and optimized for specific applications with multiwell plates and tissue microarrays. In particular, three platforms incorporate time-domain FLIM via time-correlated single photon counting in an automated fashion. We also present data from experiments performed on these platforms highlighting their automated wide-field and laser scanning capabilities designed for high-content microscopy. Devices using these designs also form radiation-beam 'end-stations' at Oxford and Surrey Universities, showing the versatility and extendibility of this approach.
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Affiliation(s)
- PR BARBER
- Gray Institute for Radiation Oncology & Biology, Dept. Of Oncology, University of OxfordOxford, U.K.
- Institute for Mathematical and Molecular Biomedicine, King's College LondonLondon, U.K.
- Randall Division of Cell and Molecular Biophysics, New Hunts House, King's College LondonLondon, U.K.
| | - IDC TULLIS
- Gray Institute for Radiation Oncology & Biology, Dept. Of Oncology, University of OxfordOxford, U.K.
| | - GP PIERCE
- Gray Institute for Radiation Oncology & Biology, Dept. Of Oncology, University of OxfordOxford, U.K.
| | - RG NEWMAN
- Gray Institute for Radiation Oncology & Biology, Dept. Of Oncology, University of OxfordOxford, U.K.
| | - J PRENTICE
- Gray Institute for Radiation Oncology & Biology, Dept. Of Oncology, University of OxfordOxford, U.K.
| | - MI ROWLEY
- Randall Division of Cell and Molecular Biophysics, New Hunts House, King's College LondonLondon, U.K.
| | - DR MATTHEWS
- Richard Dimbleby Department of Cancer Research, New Hunts House, King's College LondonLondon, U.K.
- Randall Division of Cell and Molecular Biophysics, New Hunts House, King's College LondonLondon, U.K.
- Now at The University of Queensland, Brisbane St LuciaAustralia
| | - SM AMEER-BEG
- Richard Dimbleby Department of Cancer Research, New Hunts House, King's College LondonLondon, U.K.
- Randall Division of Cell and Molecular Biophysics, New Hunts House, King's College LondonLondon, U.K.
| | - B VOJNOVIC
- Gray Institute for Radiation Oncology & Biology, Dept. Of Oncology, University of OxfordOxford, U.K.
- Randall Division of Cell and Molecular Biophysics, New Hunts House, King's College LondonLondon, U.K.
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21
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Alibhai D, Kelly DJ, Warren S, Kumar S, Margineau A, Serwa RA, Thinon E, Alexandrov Y, Murray EJ, Stuhmeier F, Tate EW, Neil MAA, Dunsby C, French PMW. Automated fluorescence lifetime imaging plate reader and its application to Förster resonant energy transfer readout of Gag protein aggregation. JOURNAL OF BIOPHOTONICS 2013. [PMID: 23184449 DOI: 10.1002/jbio.v6.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fluorescence lifetime measurements can provide quantitative readouts of local fluorophore environment and can be applied to biomolecular interactions via Förster resonant energy transfer (FRET). Fluorescence lifetime imaging (FLIM) can therefore provide a high content analysis (HCA) modality to map protein-protein interactions (PPIs) with applications in drug discovery, systems biology and basic research. We present here an automated multiwell plate reader able to perform rapid unsupervised optically sectioned FLIM of fixed and live biological samples and illustrate its potential to assay PPIs through application to Gag protein aggregation during the HIV life cycle. We demonstrate both hetero-FRET and homo-FRET readouts of protein aggregation and report the first quantitative evaluation of a FLIM HCA assay by generating dose response curves through addition of an inhibitor of Gag myristoylation. Z' factors exceeding 0.6 are realised for this FLIM FRET assay.
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Affiliation(s)
- Dominic Alibhai
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington Campus, London, UK
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22
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Alibhai D, Kelly DJ, Warren S, Kumar S, Margineau A, Serwa RA, Thinon E, Alexandrov Y, Murray EJ, Stuhmeier F, Tate EW, Neil MAA, Dunsby C, French PMW. Automated fluorescence lifetime imaging plate reader and its application to Förster resonant energy transfer readout of Gag protein aggregation. JOURNAL OF BIOPHOTONICS 2013; 6:398-408. [PMID: 23184449 PMCID: PMC3660788 DOI: 10.1002/jbio.201200185] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 10/05/2012] [Accepted: 10/14/2012] [Indexed: 05/29/2023]
Abstract
Fluorescence lifetime measurements can provide quantitative readouts of local fluorophore environment and can be applied to biomolecular interactions via Förster resonant energy transfer (FRET). Fluorescence lifetime imaging (FLIM) can therefore provide a high content analysis (HCA) modality to map protein-protein interactions (PPIs) with applications in drug discovery, systems biology and basic research. We present here an automated multiwell plate reader able to perform rapid unsupervised optically sectioned FLIM of fixed and live biological samples and illustrate its potential to assay PPIs through application to Gag protein aggregation during the HIV life cycle. We demonstrate both hetero-FRET and homo-FRET readouts of protein aggregation and report the first quantitative evaluation of a FLIM HCA assay by generating dose response curves through addition of an inhibitor of Gag myristoylation. Z' factors exceeding 0.6 are realised for this FLIM FRET assay.
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Affiliation(s)
- Dominic Alibhai
- Institute of Chemical Biology, Department of Chemistry, Imperial College LondonSouth Kensington Campus, London, SW7 2A, UK
| | - Douglas J Kelly
- Institute of Chemical Biology, Department of Chemistry, Imperial College LondonSouth Kensington Campus, London, SW7 2A, UK
| | - Sean Warren
- Institute of Chemical Biology, Department of Chemistry, Imperial College LondonSouth Kensington Campus, London, SW7 2A, UK
| | - Sunil Kumar
- Photonics Group, Department of Physics, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | - Anca Margineau
- Photonics Group, Department of Physics, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | - Remigiusz A Serwa
- Department of Chemistry, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | - Emmanuelle Thinon
- Department of Chemistry, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | - Yuriy Alexandrov
- Photonics Group, Department of Physics, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | | | - Frank Stuhmeier
- Pfizer Worldwide Research and DevelopmentPfizer Limited, Sandwich, Kent, CT13 9NJ, UK
| | - Edward W Tate
- Department of Chemistry, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | - Mark A A Neil
- Photonics Group, Department of Physics, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
| | - Chris Dunsby
- Photonics Group, Department of Physics, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
- Centre for Histopathology, Imperial College LondonDu Cane Rd, London, UK
| | - Paul M W French
- Photonics Group, Department of Physics, Imperial College LondonSouth Kensington Campus, London, SW7 2AZ, UK
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23
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Devauges V, Marquer C, Lécart S, Cossec JC, Potier MC, Fort E, Suhling K, Lévêque-Fort S. Homodimerization of amyloid precursor protein at the plasma membrane: a homoFRET study by time-resolved fluorescence anisotropy imaging. PLoS One 2012; 7:e44434. [PMID: 22973448 PMCID: PMC3433432 DOI: 10.1371/journal.pone.0044434] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 08/03/2012] [Indexed: 11/18/2022] Open
Abstract
Classical FRET (Förster Resonance Energy Transfer) using two fluorescent labels (one for the donor and another one for the acceptor) is not efficient for studying the homodimerization of a protein as only half of the homodimers formed can be identified by this technique. We thus resorted to homoFRET detected by time-resolved Fluorescence Anisotropy IMaging (tr-FAIM). To specifically image the plasma membrane of living cells, an original combination of tr-FAIM and Total Internal Reflection Fluorescence Lifetime Imaging Microscope (TIRFLIM) was implemented. The correcting factor accounting for the depolarization due to the high numerical aperture (NA) objective, mandatory for TIRF microscopy, was quantified on fluorescein solutions and on HEK293 cells expressing enhanced Green Fluorescence Protein (eGFP). Homodimerization of Amyloid Precursor Protein (APP), a key mechanism in the etiology of Alzheimer’s disease, was measured on this original set-up. We showed, both in epifluorescence and under TIRF excitation, different energy transfer rates associated with the homodimerization of wild type APP-eGFP or of a mutated APP-eGFP, which forms constitutive dimers. This original set-up thus offers promising prospects for future studies of protein homodimerization in living cells in control and pathological conditions.
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Affiliation(s)
- Viviane Devauges
- Institut des Sciences Moléculaires d’Orsay, CNRS UMR 8214, Univ. Paris Sud, Orsay, France
- Laboratoire Charles Fabry, CNRS UMR 8501, Institut d’Optique, Univ. Paris Sud, Palaiseau, France
- Centre de Photonique Biomédicale, Univ. Paris Sud, CLUPS/LUMAT FR2764, Orsay, France
| | | | - Sandrine Lécart
- Centre de Photonique Biomédicale, Univ. Paris Sud, CLUPS/LUMAT FR2764, Orsay, France
| | | | | | - Emmanuel Fort
- Institut Langevin, ESPCI ParisTech, Univ. Paris Diderot, UMR 7587, Paris, France
| | - Klaus Suhling
- Department of Physics, King’s College London, Strand, London, United Kingdom
| | - Sandrine Lévêque-Fort
- Institut des Sciences Moléculaires d’Orsay, CNRS UMR 8214, Univ. Paris Sud, Orsay, France
- Centre de Photonique Biomédicale, Univ. Paris Sud, CLUPS/LUMAT FR2764, Orsay, France
- * E-mail:
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