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Smith JT, Sinsuebphon N, Rudkouskaya A, Michalet X, Intes X, Barroso M. In vivo quantitative FRET small animal imaging: Intensity versus lifetime-based FRET. BIOPHYSICAL REPORTS 2023; 3:100110. [PMID: 37251213 PMCID: PMC10209493 DOI: 10.1016/j.bpr.2023.100110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/27/2023] [Indexed: 05/31/2023]
Abstract
Förster resonance energy transfer (FRET) microscopy is used in numerous biophysical and biomedical applications to monitor inter- and intramolecular interactions and conformational changes in the 2-10 nm range. FRET is currently being extended to in vivo optical imaging, its main application being in quantifying drug-target engagement or drug release in animal models of cancer using organic dye or nanoparticle-labeled probes. Herein, we compared FRET quantification using intensity-based FRET (sensitized emission FRET analysis with the three-cube approach using an IVIS imager) and macroscopic fluorescence lifetime (MFLI) FRET using a custom system using a time-gated-intensified charge-coupled device, for small animal optical in vivo imaging. The analytical expressions and experimental protocols required to quantify the product f D E of the FRET efficiency E and the fraction of donor molecules involved in FRET, f D , are described in detail for both methodologies. Dynamic in vivo FRET quantification of transferrin receptor-transferrin binding was acquired in live intact nude mice upon intravenous injection of a near-infrared-labeled transferrin FRET pair and benchmarked against in vitro FRET using hybridized oligonucleotides. Even though both in vivo imaging techniques provided similar dynamic trends for receptor-ligand engagement, we demonstrate that MFLI-FRET has significant advantages. Whereas the sensitized emission FRET approach using the IVIS imager required nine measurements (six of which are used for calibration) acquired from three mice, MFLI-FRET needed only one measurement collected from a single mouse, although a control mouse might be needed in a more general situation. Based on our study, MFLI therefore represents the method of choice for longitudinal preclinical FRET studies such as that of targeted drug delivery in intact, live mice.
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Affiliation(s)
- Jason T. Smith
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York
| | - Nattawut Sinsuebphon
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York
| | - Alena Rudkouskaya
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Xavier Michalet
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, California
| | - Xavier Intes
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, New York
| | - Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
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Smith JT, Sinsuebphon N, Rudkouskaya A, Michalet X, Intes X, Barroso M. in vivo quantitative FRET small animal imaging: intensity versus lifetime-based FRET. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.24.525411. [PMID: 36747671 PMCID: PMC9900789 DOI: 10.1101/2023.01.24.525411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Förster Resonance Energy Transfer (FRET) microscopy is used in numerous biophysical and biomedical applications to monitor inter- and intramolecular interactions and conformational changes in the 2-10 nm range. FRET is currently being extended to in vivo optical imaging, its main application being in quantifying drug-target engagement or drug release in animal models of cancer using organic dye or nanoparticle-labeled probes. Herein, we compared FRET quantification using intensity-based FRET (sensitized emission FRET analysis with the 3-cube approach using an IVIS imager) and macroscopic fluorescence lifetime (MFLI) FRET using a custom system using a time-gated ICCD, for small animal optical in vivo imaging. The analytical expressions and experimental protocols required to quantify the product f D E of the FRET efficiency E and the fraction of donor molecules involved in FRET, f D , are described in detail for both methodologies. Dynamic in vivo FRET quantification of transferrin receptor-transferrin binding was acquired in live intact nude mice upon intravenous injection of near infrared-labeled transferrin FRET pair and benchmarked against in vitro FRET using hybridized oligonucleotides. Even though both in vivo imaging techniques provided similar dynamic trends for receptor-ligand engagement, we demonstrate that MFLI FRET has significant advantages. Whereas the sensitized emission FRET approach using the IVIS imager required 9 measurements (6 of which are used for calibration) acquired from three mice, MFLI FRET needed only one measurement collected from a single mouse, although a control mouse might be needed in a more general situation. Based on our study, MFLI therefore represents the method of choice for longitudinal preclinical FRET studies such as that of targeted drug delivery in intact, live mice.
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Affiliation(s)
- Jason T. Smith
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Present address: Elephas, 1 Erdman Pl., Madison, WI 53705, USA
| | - Nattawut Sinsuebphon
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, NY 12180, USA
- Present address: Assistive Technology and Medical Devices Research Center, National Science and Technology Development Agency, 12120 Pathum Thani, Thailand
| | - Alena Rudkouskaya
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA
| | - Xavier Michalet
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, California, CA 90095, USA
| | - Xavier Intes
- Center for Modeling, Simulation and Imaging in Medicine (CeMSIM), Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA
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Ying D, Tseng CY, Chen PW, Lo YH, Hall D. A 30.3 fA/√Hz Biosensing Current Front-End With 139 dB Cross-Scale Dynamic Range. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2021; 15:1368-1379. [PMID: 34727038 DOI: 10.1109/tbcas.2021.3124197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This paper presents an 8-channel array of low-noise (30.3 fA/√Hz) current sensing front-ends with on-chip microelectrode electrochemical sensors. The analog front-end (AFE) consists of a 1st-order continuous-time delta-sigma (CT ΔΣ) modulator that achieves 123 fA sensitivity over a 10 Hz bandwidth and 139 dB cross-scale dynamic range with a 2-bit programmable current reference. A digital predictor and tri-level pulse width modulated (PWM) current-steering DAC realize the equivalent performance of a multi-bit ΔΣ in an area- and power-efficient manner. The AFE consumes 50.3 µW and 0.11 mm2 per readout channel. The proposed platform was used to observe protein-ligand interactions in real-time using transient induced molecular electronic spectroscopy (TIMES), a label- and immobilization-free biosensing technique.
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4
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Gadbery JE, Sampson NS. Use of an Isotope-Coded Mass Tag (ICMT) Method To Determine the Orientation of Cholesterol Oxidase on Model Membranes. Biochemistry 2018; 57:5370-5378. [PMID: 30125103 PMCID: PMC6171977 DOI: 10.1021/acs.biochem.8b00788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although the interfacial membrane protein cholesterol oxidase is structurally and kinetically well-characterized, its orientation in and mode of interaction with cholesterol-containing membranes have not been established. Cholesterol oxidase can alter the structure of the cell membrane in pathogenic bacteria and is thus a potential antimicrobial drug target. We recently developed a mass spectrometry-based isotope-coded mass tag (ICMT) labeling method to monitor the real-time solvent-accessible surface of peripheral membrane proteins, such as cholesterol oxidase. The ICMT strategy utilizes maleimide-based isotope tags that covalently react with cysteine residues. In this study, by comparing the ICMT labeling rates of cysteine variants of cholesterol oxidase, we determined which residues of the protein were engaged with the protein-lipid interface. We found that upon addition of cholesterol-containing lipid vesicles, four cysteine residues in a cluster near the substrate entrance channel are labeled more slowly with ICMT probes than in the absence of vesicles, indicating that these four residues were in contact with the membrane surface. From these data, we generated a model of how cholesterol oxidase is oriented when bound to the membrane. In conclusion, this straightforward method, which requires only microgram quantities of protein, offers several advantages over existing methods for the investigation of interfacial membrane proteins and can be applied to a number of different systems.
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Affiliation(s)
- John E Gadbery
- Biochemistry and Structural Biology Graduate Program , Stony Brook University , Stony Brook , New York 11794-5215 , United States
| | - Nicole S Sampson
- Biochemistry and Structural Biology Graduate Program , Stony Brook University , Stony Brook , New York 11794-5215 , United States.,Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
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5
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Annamdevula NS, Sweat R, Griswold JR, Trinh K, Hoffman C, West S, Deal J, Britain AL, Jalink K, Rich TC, Leavesley SJ. Spectral imaging of FRET-based sensors reveals sustained cAMP gradients in three spatial dimensions. Cytometry A 2018; 93:1029-1038. [PMID: 30176184 DOI: 10.1002/cyto.a.23572] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 06/21/2018] [Accepted: 07/09/2018] [Indexed: 11/10/2022]
Abstract
Cyclic AMP is a ubiquitous second messenger that orchestrates a variety of cellular functions over different timescales. The mechanisms underlying specificity within this signaling pathway are still not well understood. Several lines of evidence suggest the existence of spatial cAMP gradients within cells, and that compartmentalization underlies specificity within the cAMP signaling pathway. However, to date, no studies have visualized cAMP gradients in three spatial dimensions (3D: x, y, z).This is in part due to the limitations of FRET-based cAMP sensors, specifically the low signal-to-noise ratio intrinsic to all intracellular FRET probes. Here, we overcome this limitation, at least in part, by implementing spectral imaging approaches to estimate FRET efficiency when multiple fluorescent labels are used and when signals are measured from weakly expressed fluorescent proteins in the presence of background autofluorescence and stray light. Analysis of spectral image stacks in two spatial dimensions (2D) from single confocal slices indicates little or no cAMP gradients formed within pulmonary microvascular endothelial cells (PMVECs) under baseline conditions or following 10 min treatment with the adenylyl cyclase activator forskolin. However, analysis of spectral image stacks in 3D demonstrates marked cAMP gradients from the apical to basolateral face of PMVECs. Results demonstrate that spectral imaging approaches can be used to assess cAMP gradients-and in general gradients in fluorescence and FRET-within intact cells. Results also demonstrate that 2D imaging studies of localized fluorescence signals and, in particular, cAMP signals, whether using epifluorescence or confocal microscopy, may lead to erroneous conclusions about the existence and/or magnitude of gradients in either FRET or the underlying cAMP signals. Thus, with the exception of cellular structures that can be considered in one spatial dimension, such as neuronal processes, 3D measurements are required to assess mechanisms underlying compartmentalization and specificity within intracellular signaling pathways.
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Affiliation(s)
- Naga S Annamdevula
- Department of Chemical & Biomolecular Engineering, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Rachel Sweat
- Department of Chemical & Biomolecular Engineering, University of South Alabama, Mobile, Alabama
| | - John R Griswold
- Department of Chemical & Biomolecular Engineering, University of South Alabama, Mobile, Alabama
| | - Kenny Trinh
- Department of Chemical & Biomolecular Engineering, University of South Alabama, Mobile, Alabama
| | - Chase Hoffman
- Medical Sciences, University of South Alabama, Mobile, Alabama
| | - Savannah West
- Department of Biomedical Sciences, University of South Alabama, Mobile, Alabama
| | - Joshua Deal
- Department of Chemical & Biomolecular Engineering, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Andrea L Britain
- Center for Lung Biology, University of South Alabama, Mobile, Alabama.,Department of Pharmacology, University of South Alabama, Mobile, Alabama
| | - Kees Jalink
- The Netherlands Cancer Institute and van Leeuwenhoek Center for Advanced Microscopy, Amsterdam, the Netherlands
| | - Thomas C Rich
- Center for Lung Biology, University of South Alabama, Mobile, Alabama.,Department of Pharmacology, University of South Alabama, Mobile, Alabama.,College of Engineering, University of South Alabama, Mobile, Alabama
| | - Silas J Leavesley
- Department of Chemical & Biomolecular Engineering, University of South Alabama, Mobile, Alabama.,Center for Lung Biology, University of South Alabama, Mobile, Alabama.,Department of Pharmacology, University of South Alabama, Mobile, Alabama
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Abstract
The ERK1 and ERK2 (ERK1/2) cascade is a central signaling pathway activated by a wide variety of extracellular agents that transmit the messages of G Protein Coupled Receptors (GPCRs) and Receptor Tyrosine Kinases (RTKs). Being such a central pathway, the activity of the cascade is well regulated, including by dynamic changes of the subcellular localization of components of the ERK1/2 cascade. In resting cells, ERK1/2 are localized in the cytosol due to their interactions with different anchoring proteins. After stimulation, ERK1/2 are phosphorylated by MEK1/2 on their regulatory TEY motif, which permits their detachment from the anchoring proteins. This detachment exposes ERK1/2 to additional phosphorylation on two serine residues (SPS motif) within the nuclear translocation signal (NTS) of the kinases. This additional phosphorylation allows ERK1/2 to interact with importin7, which consequently promotes their translocation to the nucleus. More studies are still required in order to better understand the mechanism and consequence of the nuclear translocation of ERK1/2. In this chapter, we describe some of the techniques used to study nuclear translocation of ERK1/2 in mammalian cells. We briefly mention methods such as digitonin permeabilization and cellular fractionation, as well as overexpression of reporter constructs. More thoroughly, we describe immunofluorescence, immunoprecipitation, and proximity ligation assay (PLA) approaches that are routinely used in our laboratory. Hopefully, the increase of knowledge based on these methods will open more opportunities for the identification of new therapeutic targets for diseases where the ERK1/2 cascade is dysregulated, such as cancer, neurodegenerative diseases, and diabetes.
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Affiliation(s)
- Denise A Berti
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Rony Seger
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 76100, Israel.
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Martin KJ, McGhee EJ, Schwarz JP, Drysdale M, Brachmann SM, Stucke V, Sansom OJ, Anderson KI. Accepting from the best donor; analysis of long-lifetime donor fluorescent protein pairings to optimise dynamic FLIM-based FRET experiments. PLoS One 2018; 13:e0183585. [PMID: 29293509 PMCID: PMC5749721 DOI: 10.1371/journal.pone.0183585] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 08/07/2017] [Indexed: 11/19/2022] Open
Abstract
FRET biosensors have proven very useful tools for studying the activation of specific signalling pathways in living cells. Most biosensors designed to date have been predicated on fluorescent protein pairs that were identified by, and for use in, intensity based measurements, however fluorescence lifetime provides a more reliable measurement of FRET. Both the technology and fluorescent proteins available for FRET have moved on dramatically in the last decade. Lifetime imaging systems have become increasingly accessible and user-friendly, and there is an entire field of biology dedicated to refining and adapting different characteristics of existing and novel fluorescent proteins. This growing pool of fluorescent proteins includes the long-lifetime green and cyan fluorescent proteins Clover and mTurquoise2, the red variant mRuby2, and the dark acceptor sREACh. Here, we have tested these donors and acceptors in appropriate combinations against the standard or recommended norms (EGFP and mTFP as donors, mCherry and either Ypet or Venus as acceptors) to determine if they could provide more reliable, reproducible and quantifiable FLIM-FRET data to improve on the dynamic range compared to other donors and breadth of application of biosensor technologies. These tests were performed for comparison on both a wide-field, frequency domain system and a multiphoton, TCSPC time domain FLIM system. Clover proved to be an excellent donor with extended dynamic range in combination with mCherry on both platforms, while mRuby2 showed a high degree of variability and poor FRET efficiencies in all cases. mTFP-Venus was the most consistent cyan-yellow pair between the two FLIM methodologies, but mTurquoise2 has better dynamic range and transfers energy consistently over time to the dark acceptor sRCh. Combination of mTFP-sRCh with Clover-mCherry would allow the simultaneous use of two FLIM-FRET biosensors within one sample by eliminating the crosstalk between the yellow acceptor and green donor emissions.
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Affiliation(s)
| | - Ewan J. McGhee
- Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | | | - Martin Drysdale
- Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | | | - Volker Stucke
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Owen J. Sansom
- Beatson Institute for Cancer Research, Glasgow, United Kingdom
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McCarthy MW, Petraitiene R, Walsh TJ. Nucleic acid amplification methodologies for the detection of pulmonary mold infections. Expert Rev Mol Diagn 2017; 17:271-279. [PMID: 28218019 DOI: 10.1080/14737159.2017.1293528] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION The detection of pulmonary mold infections has historically required technically demanding methods obtained through invasive procedures. Nucleic acid amplification assays have the potential to circumvent the technical hurdles associated with diagnosis, but are not without potential pitfalls. Areas covered: In this paper, the authors review new assays for the diagnosis of pulmonary mold infections due to aspergillosis, mucormycosis, and hyalohyphomycoses as well as uncommon infections caused by dematiaceous molds. Expert commentary: Nucleic acid amplification assays have the potential to rapidly identify patients with invasive mycoses and could shorten the time to implementation of appropriate antimicrobial therapy. However, selection of appropriate patient populations will be crucial to ensure the highest Bayesian positive predictive value for any novel diagnostic platform.
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Affiliation(s)
- Matthew William McCarthy
- a Department of Medicine , Joan and Sanford I Weill Medical College of Cornell University - Hospital Medicine , New York , NY , USA
| | - Ruta Petraitiene
- b Department of Medicine , Cornell University , NY , New York City , USA
| | - Thomas J Walsh
- c Department of Medicine , Weill Cornell Medical Center - Transplantation, Oncology Infectious Diseases Program , New York , NY , USA
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9
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Pelosse M, Cottet-Rousselle C, Grichine A, Berger I, Schlattner U. Genetically Encoded Fluorescent Biosensors to Explore AMPK Signaling and Energy Metabolism. ACTA ACUST UNITED AC 2017; 107:491-523. [PMID: 27812993 DOI: 10.1007/978-3-319-43589-3_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Maintenance of energy homeostasis is a basic requirement for cell survival. Different mechanisms have evolved to cope with spatial and temporal mismatch between energy-providing and -consuming processes. Among these, signaling by AMP-activated protein kinase (AMPK) is one of the key players, regulated by and itself regulating cellular adenylate levels. Further understanding its complex cellular function requires deeper insight into its activation patterns in space and time at a single cell level. This may become possible with an increasing number of genetically encoded fluorescent biosensors, mostly based on fluorescence resonance energy transfer, which have been engineered to monitor metabolic parameters and kinase activities. Here, we review basic principles of biosensor design and function and the advantages and limitations of their use and provide an overview on existing FRET biosensors to monitor AMPK activation, ATP concentration, and ATP/ADP ratios, together with other key metabolites and parameters of energy metabolism.
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Affiliation(s)
- Martin Pelosse
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France.,Inserm, U1055 and U1209, Grenoble, France
| | - Cécile Cottet-Rousselle
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France.,Inserm, U1055 and U1209, Grenoble, France
| | - Alexei Grichine
- Inserm, U1055 and U1209, Grenoble, France.,Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | | | - Uwe Schlattner
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France. .,Inserm, U1055 and U1209, Grenoble, France.
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10
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Rich TC, Annamdevula N, Trinh K, Britain AL, Mayes SA, Griswold JR, Deal J, Hoffman C, West S, Leavesley SJ. 5D imaging approaches reveal the formation of distinct intracellular cAMP spatial gradients. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2017; 10070:100700R. [PMID: 34054188 PMCID: PMC8157067 DOI: 10.1117/12.2253164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Cyclic AMP (cAMP) is a ubiquitous second messenger known to differentially regulate many cellular functions. Several lines of evidence suggest that the distribution of cAMP within cells is not uniform. However, to date, no studies have measured the kinetics of 3D cAMP distributions within cells. This is largely due to the low signal-to-noise ratio of FRET-based probes. We previously reported that hyperspectral imaging improves the signal-to-noise ratio of FRET measurements. Here we utilized hyperspectral imaging approaches to measure FRET signals in five dimensions (5D) - three spatial (x, y, z), wavelength (λ), and time (t) - allowing us to visualize cAMP gradients in pulmonary endothelial cells. cAMP levels were measured using a FRET-based sensor (H188) comprised of a cAMP binding domain sandwiched between FRET donor and acceptor - Turquoise and Venus fluorescent proteins. We observed cAMP gradients in response to 0.1 or 1 μM isoproterenol, 0.1 or 1 μM PGE1, or 50 μM forskolin. Forskolin- and isoproterenol-induced cAMP gradients formed from the apical (high cAMP) to basolateral (low cAMP) face of cells. In contrast, PGE1-induced cAMP gradients originated from both the basolateral and apical faces of cells. Data suggest that 2D (x,y) studies of cAMP compartmentalization may lead to erroneous conclusions about the existence of cAMP gradients, and that 3D (x,y,z) studies are required to assess mechanisms of signaling specificity. Results demonstrate that 5D imaging technologies are powerful tools for measuring biochemical processes in discrete subcellular domains. This work was supported by NIH P01HL066299, R01HL058506, S10RR027535, AHA 16PRE27130004 and the Abraham Mitchell Cancer Research Fund.
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Affiliation(s)
- Thomas C Rich
- Pharmacology, University of South Alabama, AL 36688
- Center for Lung Biology, University of South Alabama, AL 36688
- Basic Medical Sciences Graduate Program, University of South Alabama, AL 36688
| | - Naga Annamdevula
- Center for Lung Biology, University of South Alabama, AL 36688
- Basic Medical Sciences Graduate Program, University of South Alabama, AL 36688
| | - Kenny Trinh
- Chemical and Biomolecular Engineering, University of South Alabama, AL 36688
| | - Andrea L Britain
- Pharmacology, University of South Alabama, AL 36688
- Center for Lung Biology, University of South Alabama, AL 36688
| | - Samuel A Mayes
- Chemical and Biomolecular Engineering, University of South Alabama, AL 36688
| | - John R Griswold
- Chemical and Biomolecular Engineering, University of South Alabama, AL 36688
| | - Joshua Deal
- Center for Lung Biology, University of South Alabama, AL 36688
- Basic Medical Sciences Graduate Program, University of South Alabama, AL 36688
| | | | - Savannah West
- Biomedical Sciences, University of South Alabama, AL 36688
| | - Silas J Leavesley
- Pharmacology, University of South Alabama, AL 36688
- Center for Lung Biology, University of South Alabama, AL 36688
- Basic Medical Sciences Graduate Program, University of South Alabama, AL 36688
- Chemical and Biomolecular Engineering, University of South Alabama, AL 36688
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11
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Várnai P, Gulyás G, Tóth DJ, Sohn M, Sengupta N, Balla T. Quantifying lipid changes in various membrane compartments using lipid binding protein domains. Cell Calcium 2016; 64:72-82. [PMID: 28088320 DOI: 10.1016/j.ceca.2016.12.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 11/30/2022]
Abstract
One of the largest challenges in cell biology is to map the lipid composition of the membranes of various organelles and define the exact location of processes that control the synthesis and distribution of lipids between cellular compartments. The critical role of phosphoinositides, low-abundant lipids with rapid metabolism and exceptional regulatory importance in the control of almost all aspects of cellular functions created the need for tools to visualize their localizations and dynamics at the single cell level. However, there is also an increasing need for methods to determine the cellular distribution of other lipids regulatory or structural, such as diacylglycerol, phosphatidic acid, or other phospholipids and cholesterol. This review will summarize recent advances in this research field focusing on the means by which changes can be described in more quantitative terms.
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Affiliation(s)
- Péter Várnai
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Gergő Gulyás
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Dániel J Tóth
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, United States; Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Mira Sohn
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, United States
| | - Nivedita Sengupta
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, United States
| | - Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, United States.
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13
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Transient Induced Molecular Electronic Spectroscopy (TIMES) for study of protein-ligand interactions. Sci Rep 2016; 6:35570. [PMID: 27759045 PMCID: PMC5069662 DOI: 10.1038/srep35570] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 10/03/2016] [Indexed: 12/22/2022] Open
Abstract
We present a method, Transient Induced Molecular Electronic Spectroscopy (TIMES), to detect protein-ligand interactions without any protein engineering or chemical modification. We developed a physics model for the TIMES signal and mathematically formulated the problem to attain physical insight of protein-ligand interactions without any disturbances by molecular probes, fluorescent labels, or immobilization of molecules. To demonstrate the functionality of this method, we have used the TIMES signals to find the dissociation constants for the affinity of reactions, the shear-stress dependent adsorption time of molecules on surface, and other interesting features of protein-ligand interaction in native conditions. As a unique tool, TIMES offers a simple and effective method to investigate fundamental protein chemistry and drug discoveries.
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