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Wardhani K, Levina A, Grau GER, Lay PA. Fluorescent, phosphorescent, magnetic resonance contrast and radioactive tracer labelling of extracellular vesicles. Chem Soc Rev 2024; 53:6779-6829. [PMID: 38828885 DOI: 10.1039/d2cs00238h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
This review focusses on the significance of fluorescent, phosphorescent labelling and tracking of extracellular vesicles (EVs) for unravelling their biology, pathophysiology, and potential diagnostic and therapeutic uses. Various labeling strategies, such as lipid membrane, surface protein, luminal, nucleic acid, radionuclide, quantum dot labels, and metal complex-based stains, are evaluated for visualizing and characterizing EVs. Direct labelling with fluorescent lipophilic dyes is simple but generally lacks specificity, while surface protein labelling offers selectivity but may affect EV-cell interactions. Luminal and nucleic acid labelling strategies have their own advantages and challenges. Each labelling approach has strengths and weaknesses, which require a suitable probe and technique based on research goals, but new tetranuclear polypyridylruthenium(II) complexes as phosphorescent probes have strong phosphorescence, selective staining, and stability. Future research should prioritize the design of novel fluorescent probes and labelling platforms that can significantly enhance the efficiency, accuracy, and specificity of EV labeling, while preserving their composition and functionality. It is crucial to reduce false positive signals and explore the potential of multimodal imaging techniques to gain comprehensive insights into EVs.
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Affiliation(s)
- Kartika Wardhani
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia.
- Biochemistry and Biotechnology (B-TEK) Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA
| | - Aviva Levina
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia.
| | - Georges E R Grau
- Sydney Nano, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Sydney Cancer Network, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Marie Bashir Institute, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Vascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Peter A Lay
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia.
- Sydney Nano, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Sydney Cancer Network, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Marie Bashir Institute, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Sydney Analytical, The University of Sydney, Sydney, New South Wales, 2006, Australia
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2
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Cherepanov DA, Milanovsky GE, Neverov KV, Obukhov YN, Maleeva YV, Aybush AV, Kritsky MS, Nadtochenko VA. Exciton interactions of chlorophyll tetramer in water-soluble chlorophyll-binding protein BoWSCP. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 309:123847. [PMID: 38217986 DOI: 10.1016/j.saa.2024.123847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/15/2024]
Abstract
The exciton interaction of four chlorophyll a (Chl a) molecules in a symmetrical tetrameric complex of the water-soluble chlorophyll-binding protein BoWSCP was analyzed in the pH range of 3-11. Exciton splitting ΔE = 232 ± 2 cm-1 of the Qy band of Chl a into two subcomponents with relative intensities of 78.1 ± 0.7 % and 21.9 ± 0.7 % was determined by a joint decomposition of the absorption and circular dichroism spectra into Gaussian functions. The exciton coupling parameters were calculated based on the BoWSCP atomic structure in three approximations: the point dipole model, the distributed atomic monopoles, and direct ab initio calculations in the TDDFT/PCM approximation. The Coulomb interactions of monomers were calculated within the continuum model using three values of optical permittivity. The models based on the properties of free Chl a in solution suffer from significant errors both in estimating the absolute value of the exciton interaction and in the relative intensity of exciton transitions. Calculations within the TDDFT/PCM approximation reproduce the experimentally determined parameters of the exciton splitting and the relative intensities of the exciton bands. The following factors of pigment-protein and pigment-pigment interactions were examined: deviation of the macrocycle geometry from the planar conformation of free Chl; the formation of hydrogen bonds between the macrocycle and water molecules; the overlap of wave functions of monomers at close distances. The most significant factor is the geometrical deformation of the porphyrin macrocycle, which leads to an increase in the dipole moment of Chl monomer from 5.5 to 6.9 D and to a rotation of the dipole moment by 15° towards the cyclopentane ring. The contributions of resonant charge-transfer states to the wave functions of the Chl dimer were determined and the transition dipole moments of the symmetric and antisymmetric charge-transfer states were estimated.
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Affiliation(s)
- D A Cherepanov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Kosygina str., 4, Russian Federation; A.N. Belozersky Institute Of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Leninskye gory, 1b.40, Russian Federation.
| | - G E Milanovsky
- A.N. Belozersky Institute Of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Leninskye gory, 1b.40, Russian Federation
| | - K V Neverov
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences", 119071 Moscow, Leninsky prospect, 33b.2, Russian Federation; Faculty of Biology, Moscow State University, 119234 Moscow, Leninskye gory, 1b.12, Russian Federation
| | - Yu N Obukhov
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences", 119071 Moscow, Leninsky prospect, 33b.2, Russian Federation
| | - Yu V Maleeva
- Faculty of Biology, Moscow State University, 119234 Moscow, Leninskye gory, 1b.12, Russian Federation
| | - A V Aybush
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Kosygina str., 4, Russian Federation
| | - M S Kritsky
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences", 119071 Moscow, Leninsky prospect, 33b.2, Russian Federation
| | - V A Nadtochenko
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Kosygina str., 4, Russian Federation; Department of Chemistry, Moscow State University, 119991 Moscow, Leninskye gory, 1b.3, Russian Federation
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3
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Mo Y, Zhou H, Xu J, Chen X, Li L, Zhang S. Genetically encoded fluorescence lifetime biosensors: overview, advances, and opportunities. Analyst 2023; 148:4939-4953. [PMID: 37721109 DOI: 10.1039/d3an01201h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Genetically encoded biosensors based on fluorescent proteins (FPs) are powerful tools for tracking analytes and cellular events with high spatial and temporal resolution in living cells and organisms. Compared with intensiometric readout and ratiometric readout, fluorescence lifetime readout provides absolute measurements, independent of the biosensor expression level and instruments. Thus, genetically encoded fluorescence lifetime biosensors play a vital role in facilitating accurate quantitative assessments within intricate biological systems. In this review, we first provide a concise description of the categorization and working mechanism of genetically encoded fluorescence lifetime biosensors. Subsequently, we elaborate on the combination of the fluorescence lifetime imaging technique and lifetime analysis methods with fluorescence lifetime biosensors, followed by their application in monitoring the dynamics of environment parameters, analytes and cellular events. Finally, we discuss worthwhile considerations for the design, optimization and development of fluorescence lifetime-based biosensors from three representative cases.
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Affiliation(s)
- Yidan Mo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Huangmei Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Jinming Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Xihang Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Lei Li
- School of Science, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China.
| | - Sanjun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- NYU-ECNU Institute of Physics at NYU Shanghai, No. 3663, North Zhongshan Rd, Shanghai 200062, China.
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4
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Joron K, Viegas JO, Haas-Neill L, Bier S, Drori P, Dvir S, Lim PSL, Rauscher S, Meshorer E, Lerner E. Fluorescent protein lifetimes report densities and phases of nuclear condensates during embryonic stem-cell differentiation. Nat Commun 2023; 14:4885. [PMID: 37573411 PMCID: PMC10423231 DOI: 10.1038/s41467-023-40647-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 08/03/2023] [Indexed: 08/14/2023] Open
Abstract
Fluorescent proteins (FP) are frequently used for studying proteins inside cells. In advanced fluorescence microscopy, FPs can report on additional intracellular variables. One variable is the local density near FPs, which can be useful in studying densities within cellular bio-condensates. Here, we show that a reduction in fluorescence lifetimes of common monomeric FPs reports increased levels of local densities. We demonstrate the use of this fluorescence-based variable to report the distribution of local densities within heterochromatin protein 1α (HP1α) in mouse embryonic stem cells (ESCs), before and after early differentiation. We find that local densities within HP1α condensates in pluripotent ESCs are heterogeneous and cannot be explained by a single liquid phase. Early differentiation, however, induces a change towards a more homogeneous distribution of local densities, which can be explained as a liquid-like phase. In conclusion, we provide a fluorescence-based method to report increased local densities and apply it to distinguish between homogeneous and heterogeneous local densities within bio-condensates.
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Affiliation(s)
- Khalil Joron
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Juliane Oliveira Viegas
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Liam Haas-Neill
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Sariel Bier
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Paz Drori
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Shani Dvir
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Patrick Siang Lin Lim
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Sarah Rauscher
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Eran Meshorer
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel.
- Edmond and Lily Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
| | - Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
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Rodimova S, Mozherov A, Elagin V, Karabut M, Shchechkin I, Kozlov D, Krylov D, Gavrina A, Bobrov N, Zagainov V, Zagaynova E, Kuznetsova D. Label-Free Imaging Techniques to Evaluate Metabolic Changes Caused by Toxic Liver Injury in PCLS. Int J Mol Sci 2023; 24:ijms24119195. [PMID: 37298155 DOI: 10.3390/ijms24119195] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023] Open
Abstract
Abuse with hepatotoxic agents is a major cause of acute liver failure. The search for new criteria indicating the acute or chronic pathological processes is still a challenging issue that requires the selection of effective tools and research models. Multiphoton microscopy with second harmonic generation (SHG) and fluorescence lifetime imaging microscopy (FLIM) are modern label-free methods of optical biomedical imaging for assessing the metabolic state of hepatocytes, therefore reflecting the functional state of the liver tissue. The aim of this work was to identify characteristic changes in the metabolic state of hepatocytes in precision-cut liver slices (PCLSs) under toxic damage by some of the most common toxins: ethanol, carbon tetrachloride (CCl4) and acetaminophen (APAP), commonly known as paracetamol. We have determined characteristic optical criteria for toxic liver damage, and these turn out to be specific for each toxic agent, reflecting the underlying pathological mechanisms of toxicity. The results obtained are consistent with standard methods of molecular and morphological analysis. Thus, our approach, based on optical biomedical imaging, is effective for intravital monitoring of the state of liver tissue in the case of toxic damage or even in cases of acute liver injury.
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Affiliation(s)
- Svetlana Rodimova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
| | - Artem Mozherov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Laboratory of Molecular Genetic Research of the Institute of Clinical Medicine, Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Vadim Elagin
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
| | - Maria Karabut
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
| | - Ilya Shchechkin
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Laboratory of Molecular Genetic Research of the Institute of Clinical Medicine, Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Dmitry Kozlov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Laboratory of Molecular Genetic Research of the Institute of Clinical Medicine, Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Dmitry Krylov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Laboratory of Molecular Genetic Research of the Institute of Clinical Medicine, Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Alena Gavrina
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Laboratory of Molecular Genetic Research of the Institute of Clinical Medicine, Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Nikolai Bobrov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- The Volga District Medical Centre of Federal Medical and Biological Agency, 14 Ilinskaya St., 603000 Nizhny Novgorod, Russia
| | - Vladimir Zagainov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Nizhny Novgorod Regional Clinical Oncologic Dispensary, Delovaya St., 11/1, 603126 Nizhny Novgorod, Russia
| | - Elena Zagaynova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
| | - Daria Kuznetsova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia
- Laboratory of Molecular Genetic Research of the Institute of Clinical Medicine, Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
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6
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Rodimova S, Mozherov A, Elagin V, Karabut M, Shchechkin I, Kozlov D, Krylov D, Gavrina A, Kaplin V, Epifanov E, Minaev N, Bardakova K, Solovieva A, Timashev P, Zagaynova E, Kuznetsova D. FLIM imaging revealed spontaneous osteogenic differentiation of stem cells on gradient pore size tissue-engineered constructs. Stem Cell Res Ther 2023; 14:81. [PMID: 37046354 PMCID: PMC10091689 DOI: 10.1186/s13287-023-03307-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
BACKGROUND There is an urgent clinical need for targeted strategies aimed at the treatment of bone defects resulting from fractures, infections or tumors. 3D scaffolds represent an alternative to allogeneic MSC transplantation, due to their mimicry of the cell niche and the preservation of tissue structure. The actual structure of the scaffold itself can affect both effective cell adhesion and its osteoinductive properties. Currently, the effects of the structural heterogeneity of scaffolds on the behavior of cells and tissues at the site of damage have not been extensively studied. METHODS Both homogeneous and heterogeneous scaffolds were generated from poly(L-lactic acid) methacrylated in supercritical carbon dioxide medium and were fabricated by two-photon polymerization. The homogeneous scaffolds consist of three layers of cylinders of the same diameter, whereas the heterogeneous (gradient pore sizes) scaffolds contain the middle layer of cylinders of increased diameter, imitating the native structure of spongy bone. To evaluate the osteoinductive properties of both types of scaffold, we performed in vitro and in vivo experiments. Multiphoton microscopy with fluorescence lifetime imaging microscopy was used for determining the metabolic states of MSCs, as a sensitive marker of cell differentiation. The results obtained from this approach were verified using standard markers of osteogenic differentiation and based on data from morphological analysis. RESULTS The heterogeneous scaffolds showed improved osteoinductive properties, accelerated the metabolic rearrangements associated with osteogenic differentiation, and enhanced the efficiency of bone tissue recovery, thereby providing for both the development of appropriate morphology and mineralization. CONCLUSIONS The authors suggest that the heterogeneous tissue constructs are a promising tool for the restoration of bone defects. And, furthermore, that our results demonstrate that the use of label-free bioimaging methods can be considered as an effective approach for intravital assessment of the efficiency of differentiation of MSCs on scaffolds.
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Affiliation(s)
- Svetlana Rodimova
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022.
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000.
| | - Artem Mozherov
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Vadim Elagin
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Maria Karabut
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Ilya Shchechkin
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Dmitry Kozlov
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Dmitry Krylov
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Alena Gavrina
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Vladislav Kaplin
- Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, 4 Kosygina St, Moscow, Russia, 119991
| | - Evgenii Epifanov
- Research Center "Crystallography and Photonics", Institute of Photonic Technologies, Russian Academy of Sciences, 2 Pionerskaya St, Troitsk, Moscow, Russia, 108840
| | - Nikita Minaev
- Institute for Regenerative Medicine, Sechenov University, 8-2 Trubetskaya Str, Moscow, Russia, 119991
| | - Ksenia Bardakova
- Research Center "Crystallography and Photonics", Institute of Photonic Technologies, Russian Academy of Sciences, 2 Pionerskaya St, Troitsk, Moscow, Russia, 108840
- Institute for Regenerative Medicine, Sechenov University, 8-2 Trubetskaya Str, Moscow, Russia, 119991
| | - Anna Solovieva
- Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, 4 Kosygina St, Moscow, Russia, 119991
| | - Peter Timashev
- Institute for Regenerative Medicine, Sechenov University, 8-2 Trubetskaya Str, Moscow, Russia, 119991
- World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov University, 8-2 Trubetskaya Str, Moscow, Russia, 119991
| | - Elena Zagaynova
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
| | - Daria Kuznetsova
- N. I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., Nizhny Novgorod, Russia, 603022
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., Nizhny Novgorod, Russia, 603000
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7
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Welsh JA, Arkesteijn GJA, Bremer M, Cimorelli M, Dignat-George F, Giebel B, Görgens A, Hendrix A, Kuiper M, Lacroix R, Lannigan J, van Leeuwen TG, Lozano-Andrés E, Rao S, Robert S, de Rond L, Tang VA, Tertel T, Yan X, Wauben MHM, Nolan JP, Jones JC, Nieuwland R, van der Pol E. A compendium of single extracellular vesicle flow cytometry. J Extracell Vesicles 2023; 12:e12299. [PMID: 36759917 PMCID: PMC9911638 DOI: 10.1002/jev2.12299] [Citation(s) in RCA: 53] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 11/29/2022] [Accepted: 12/17/2022] [Indexed: 02/11/2023] Open
Abstract
Flow cytometry (FCM) offers a multiparametric technology capable of characterizing single extracellular vesicles (EVs). However, most flow cytometers are designed to detect cells, which are larger than EVs. Whereas cells exceed the background noise, signals originating from EVs partly overlap with the background noise, thereby making EVs more difficult to detect than cells. This technical mismatch together with complexity of EV-containing fluids causes limitations and challenges with conducting, interpreting and reproducing EV FCM experiments. To address and overcome these challenges, researchers from the International Society for Extracellular Vesicles (ISEV), International Society for Advancement of Cytometry (ISAC), and the International Society on Thrombosis and Haemostasis (ISTH) joined forces and initiated the EV FCM working group. To improve the interpretation, reporting, and reproducibility of future EV FCM data, the EV FCM working group published an ISEV position manuscript outlining a framework of minimum information that should be reported about an FCM experiment on single EVs (MIFlowCyt-EV). However, the framework contains limited background information. Therefore, the goal of this compendium is to provide the background information necessary to design and conduct reproducible EV FCM experiments. This compendium contains background information on EVs, the interaction between light and EVs, FCM hardware, experimental design and preanalytical procedures, sample preparation, assay controls, instrument data acquisition and calibration, EV characterization, and data reporting. Although this compendium focuses on EVs, many concepts and explanations could also be applied to FCM detection of other particles within the EV size range, such as bacteria, lipoprotein particles, milk fat globules, and viruses.
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Affiliation(s)
- Joshua A Welsh
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ger J A Arkesteijn
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Michel Bremer
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Michael Cimorelli
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Department of Chemical Engineering, Drexel University, Philadelphia, Pennsylvania, USA
| | - Françoise Dignat-George
- Aix Marseille Univ, INSERM, INRAE, C2VN, UFR de Pharmacie, Marseille, France
- Hematology and Vascular Biology Department, CHU La Conception, Assistance Publique-Hôpitaux de Marseille, Marseille, France
| | - Bernd Giebel
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - André Görgens
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Clinical Research Center, Department for Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Evox Therapeutics Ltd, Oxford, UK
| | - An Hendrix
- Laboratory of Experimental Cancer Research, Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - Martine Kuiper
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Dutch Metrology Institute, VSL, Delft, The Netherlands
| | - Romaric Lacroix
- Aix Marseille Univ, INSERM, INRAE, C2VN, UFR de Pharmacie, Marseille, France
- Hematology and Vascular Biology Department, CHU La Conception, Assistance Publique-Hôpitaux de Marseille, Marseille, France
| | - Joanne Lannigan
- Flow Cytometry Support Services, LLC, Arlington, Virginia, USA
| | - Ton G van Leeuwen
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis and Ischemic Syndromes, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Estefanía Lozano-Andrés
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Shoaib Rao
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Stéphane Robert
- Aix Marseille Univ, INSERM, INRAE, C2VN, UFR de Pharmacie, Marseille, France
- Hematology and Vascular Biology Department, CHU La Conception, Assistance Publique-Hôpitaux de Marseille, Marseille, France
| | - Leonie de Rond
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Vera A Tang
- Flow Cytometry & Virometry Core Facility, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Tobias Tertel
- Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Xiaomei Yan
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, People's Republic of China
| | - Marca H M Wauben
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - John P Nolan
- Scintillon Institute, San Diego, California, USA
- Cellarcus Biosciences, San Diego, California, USA
| | - Jennifer C Jones
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Rienk Nieuwland
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis and Ischemic Syndromes, Amsterdam, The Netherlands
| | - Edwin van der Pol
- Vesicle Observation Center, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Experimental Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Biomedical Engineering & Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis and Ischemic Syndromes, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
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8
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Gul B, Syed F, Khan S, Iqbal A, Ahmad I. Characterization of extracellular vesicles by flow cytometry: Challenges and promises. Micron 2022; 161:103341. [DOI: 10.1016/j.micron.2022.103341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 08/03/2022] [Accepted: 08/03/2022] [Indexed: 10/16/2022]
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9
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Quintanilla M, Henriksen-Lacey M, Renero-Lecuna C, Liz-Marzán LM. Challenges for optical nanothermometry in biological environments. Chem Soc Rev 2022; 51:4223-4242. [PMID: 35587578 DOI: 10.1039/d2cs00069e] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Temperature monitoring is useful in medical diagnosis, and essential during hyperthermia treatments to avoid undesired cytotoxic effects. Aiming to control heating doses, different temperature monitoring strategies have been developed, largely based on luminescent materials, a.k.a. nanothermometers. However, for such nanothermometers to work, both excitation and emission light beams must travel through tissue, making its optical properties a relevant aspect to be considered during the measurements. In complex tissues, heterogeneity, and real-time alterations as a result of therapeutic treatment may have an effect on light-tissue interaction, hindering accuracy in the thermal reading. In this Tutorial Review we discuss various methods in which nanothermometers can be used for temperature sensing within heterogeneous environments. We discuss recent developments in optical (nano)thermometry, focusing on the incorporation of luminescent nanoparticles into complex in vitro and in vivo models. Methods formulated to avoid thermal misreading are also discussed, considering their respective advantages and drawbacks.
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Affiliation(s)
- Marta Quintanilla
- Materials Physics Department, Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente, 7. 28049, Madrid, Spain.
| | - Malou Henriksen-Lacey
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), Paseo de Miramón 194, 20014 Donostia-San Sebastián, Spain. .,Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Paseo de Miramón 194, 20014 Donostia-San Sebastián, Spain
| | - Carlos Renero-Lecuna
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), Paseo de Miramón 194, 20014 Donostia-San Sebastián, Spain. .,Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Paseo de Miramón 194, 20014 Donostia-San Sebastián, Spain
| | - Luis M Liz-Marzán
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), Paseo de Miramón 194, 20014 Donostia-San Sebastián, Spain. .,Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Paseo de Miramón 194, 20014 Donostia-San Sebastián, Spain.,Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
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10
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Kim D, Moon S, Hwang W, Young Kim D. Use of nanosecond excitation pulses in fluorescence lifetime measurement via phasor analysis. OPTICS EXPRESS 2022; 30:14677-14685. [PMID: 35473207 DOI: 10.1364/oe.450761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/02/2022] [Indexed: 06/14/2023]
Abstract
We investigated the possibility of using long excitation pulses in fluorescence lifetime imaging microscopy (FLIM) using phasor analysis. It has long been believed that the pulse width of an excitation laser must be shorter than the lifetime of a fluorophore in a time-domain FLIM system. Even though phasor analysis can effectively minimize the pulse effect by using deconvolution, the precision of a measured lifetime can be degraded seriously. Here, we provide a fundamental theory on pulse-width-dependent measurement precisions in lifetime measurement in the phasor plane. Our theory predicts that high-precision lifetimes can be obtained even with a laser whose pulse width is four times larger than the lifetime of a fluorophore. We have experimentally demonstrated this by measuring the lifetimes of fluorescence probes with 2.57 ns and 3.75 ns lifetimes by using various pulse widths (0.52-38 ns) and modulation frequencies (10-200 MHz). We believe our results open a new possibility of using long pulse-width lasers for high-precision FLIM.
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11
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Saad Y, Gazzah MH, Mougin K, Selmi M, Belmabrouk H. Sensitive Detection of SARS-CoV-2 Using a Novel Plasmonic Fiber Optic Biosensor Design. PLASMONICS (NORWELL, MASS.) 2022; 17:1489-1500. [PMID: 35493722 PMCID: PMC9034078 DOI: 10.1007/s11468-022-01639-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/11/2022] [Indexed: 06/01/2023]
Abstract
The coronavirus (COVID-19) pandemic has put the entire world at risk and caused an economic downturn in most countries. This work provided theoretical insight into a novel fiber optic-based plasmonic biosensor that can be used for sensitive detection of SARS-CoV-2. The aim was always to achieve reliable, sensitive, and reproducible detection. The proposed configuration is based on Ag-Au alloy nanoparticle films covered with a layer of graphene which promotes the molecular adsorption and a thiol-tethered DNA layer as a ligand. Here, the combination of two recent approaches in a single configuration is very promising and can only lead to considerable improvement. We have theoretically analyzed the sensor performance in terms of sensitivity and resolution. To highlight the importance of the new configuration, a comparison was made with two other sensors. One is based on gold nanoparticles incorporated into a host medium; the other is composed of a bimetallic Ag-Au layer in the massive state. The numerical results obtained have been validated and show that the proposed configuration offers better sensitivity (7100 nm\RIU) and good resolution (figure of merit; FOM = 38.88RIU - 1 and signal-to-noise ratio; SNR = 0.388). In addition, a parametric study was performed such as the graphene layers' number and the size of the nanoparticles.
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Affiliation(s)
- Yosra Saad
- Laboratory of Quantum and Statistical Physics, Faculty of Sciences of Monastir, University of Monastir, 5019 Monastir, Tunisia
| | - Mohamed Hichem Gazzah
- Laboratory of Quantum and Statistical Physics, Faculty of Sciences of Monastir, University of Monastir, 5019 Monastir, Tunisia
| | - Karine Mougin
- University of Haute-Alsace, Institute of Materials Science of Mulhouse, IS2M-CNRS-UMR 7361, 15 Rue Jean Starcky, 68057 Mulhouse, France
| | - Marwa Selmi
- Laboratory of Electronics and Microelectronics, Faculty of Science of Monastir, University of Monastir, 5019 Monastir, Tunisia
| | - Hafedh Belmabrouk
- Laboratory of Electronics and Microelectronics, Faculty of Science of Monastir, University of Monastir, 5019 Monastir, Tunisia
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12
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Habertheuer A, Ram C, Schmierer M, Chatterjee S, Hu R, Freas A, Zielinski P, Rogers W, Silvestro EM, McGrane M, Moore JS, Korutla L, Siddiqui S, Xin Y, Rizi R, Qin Tao J, Kreisel D, Naji A, Ochiya T, Vallabhajosyula P. Circulating Donor Lung-specific Exosome Profiles Enable Noninvasive Monitoring of Acute Rejection in a Rodent Orthotopic Lung Transplantation Model. Transplantation 2022; 106:754-766. [PMID: 33993180 DOI: 10.1097/tp.0000000000003820] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND There is a critical need for development of biomarkers to noninvasively monitor for lung transplant rejection. We investigated the potential of circulating donor lung-specific exosome profiles for time-sensitive diagnosis of acute rejection in a rat orthotopic lung transplant model. METHODS Left lungs from Wistar transgenic rats expressing human CD63-GFP, an exosome marker, were transplanted into fully MHC-mismatched Lewis recipients or syngeneic controls. Recipient blood was collected between 4 h and 10 d after transplantation, and plasma was processed for exosome isolation by size exclusion column chromatography and ultracentrifugation. Circulating donor exosomes were profiled using antihuman CD63 antibody quantum dot on the nanoparticle detector and via GFP trigger on the nanoparticle flow cytometer. RESULTS In syngeneic controls, steady-state levels of circulating donor exosomes were detected at all posttransplant time points. Allogeneic grafts lost perfusion by day 8, consistent with acute rejection. Levels of circulating donor exosomes peaked on day 1, decreased significantly by day 2, and then reached baseline levels by day 3. Notably, decrease in peripheral donor exosome levels occurred before grafts had histological evidence of acute rejection. CONCLUSIONS Circulating donor lung-specific exosome profiles enable an early detection of acute rejection before histologic manifestation of injury to the pulmonary allograft. As acute rejection episodes are a major risk factor for the development of chronic lung allograft dysfunction, this biomarker may provide a novel noninvasive diagnostic platform that can translate into earlier therapeutic intervention for lung transplant patients.
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Affiliation(s)
- Andreas Habertheuer
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
- Division of Cardiac Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Chirag Ram
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | - Shampa Chatterjee
- Institute for Environmental Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Robert Hu
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Andrew Freas
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Patrick Zielinski
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Wade Rogers
- Still Pond Cytomics LLC, West Chester, PA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Eva M Silvestro
- Still Pond Cytomics LLC, West Chester, PA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | - Jonni S Moore
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Laxminarayana Korutla
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
- Division of Cardiac Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT
| | - Sarmad Siddiqui
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Yi Xin
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Rahim Rizi
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Jian Qin Tao
- Institute for Environmental Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Daniel Kreisel
- Departments of Surgery, Pathology & Immunology, Washington University, St. Louis, MI
| | - Ali Naji
- Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Takahiro Ochiya
- Department of Molecular and Cellular Medicine, Tokyo Medical University, Tokyo, Japan
| | - Prashanth Vallabhajosyula
- Division of Cardiovascular Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
- Division of Cardiac Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT
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13
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Kim HJ, Rames MJ, Tassi Yunga S, Armstrong R, Morita M, Ngo ATP, McCarty OJT, Civitci F, Morgan TK, Ngo TTM. Irreversible alteration of extracellular vesicle and cell-free messenger RNA profiles in human plasma associated with blood processing and storage. Sci Rep 2022; 12:2099. [PMID: 35136102 PMCID: PMC8827089 DOI: 10.1038/s41598-022-06088-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 01/19/2022] [Indexed: 12/31/2022] Open
Abstract
The discovery and utility of clinically relevant circulating biomarkers depend on standardized methods that minimize preanalytical errors. Despite growing interest in studying extracellular vesicles (EVs) and cell-free messenger RNA (cf-mRNA) as potential biomarkers, how blood processing and freeze/thaw impacts the profiles of these analytes in plasma was not thoroughly understood. We utilized flow cytometric analysis to examine the effect of differential centrifugation and a freeze/thaw cycle on EV profiles. Utilizing flow cytometry postacquisition analysis software (FCMpass) to calibrate light scattering and fluorescence, we revealed how differential centrifugation and post-freeze/thaw processing removes and retains EV subpopulations. Additionally, cf-mRNA levels measured by RT-qPCR profiles from a panel of housekeeping, platelet, and tissue-specific genes were preferentially affected by differential centrifugation and post-freeze/thaw processing. Critically, freezing plasma containing residual platelets yielded irreversible ex vivo generation of EV subpopulations and cf-mRNA transcripts, which were not removable by additional processing after freeze/thaw. Our findings suggest the importance of minimizing confounding variation attributed to plasma processing and platelet contamination.
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Affiliation(s)
- Hyun Ji Kim
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
| | - Matthew J Rames
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
| | - Samuel Tassi Yunga
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
| | - Randall Armstrong
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA
| | - Mayu Morita
- Department of Pathology, Oregon Health and Science University, Portland, OR, USA
| | - Anh T P Ngo
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
| | - Owen J T McCarty
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
| | - Fehmi Civitci
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA
| | - Terry K Morgan
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA
- Department of Pathology, Oregon Health and Science University, Portland, OR, USA
| | - Thuy T M Ngo
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute (CEDAR), Oregon Health and Science University, 2720 SW Moody Ave, KR-CEDR, Portland, OR, 97201, USA.
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR, USA.
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA.
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14
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Misinterpretation of solid sphere equivalent refractive index measurements and smallest detectable diameters of extracellular vesicles by flow cytometry. Sci Rep 2021; 11:24151. [PMID: 34921157 PMCID: PMC8683472 DOI: 10.1038/s41598-021-03015-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 11/25/2021] [Indexed: 11/24/2022] Open
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15
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Rodimova S, Elagin V, Karabut M, Koryakina I, Timin A, Zagainov V, Zyuzin M, Zagaynova E, Kuznetsova D. Toxicological Analysis of Hepatocytes Using FLIM Technique: In Vitro versus Ex Vivo Models. Cells 2021; 10:2894. [PMID: 34831114 PMCID: PMC8616382 DOI: 10.3390/cells10112894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/19/2021] [Accepted: 10/23/2021] [Indexed: 12/03/2022] Open
Abstract
The search for new criteria indicating acute or chronic pathological processes resulting from exposure to toxic agents, testing of drugs for potential hepatotoxicity, and fundamental study of the mechanisms of hepatotoxicity at a molecular level still represents a challenging issue that requires the selection of adequate research models and tools. Microfluidic chips (MFCs) offer a promising in vitro model for express analysis and are easy to implement. However, to obtain comprehensive information, more complex models are needed. A fundamentally new label-free approach for studying liver pathology is fluorescence-lifetime imaging microscopy (FLIM). We obtained FLIM data on both the free and bound forms of NAD(P)H, which is associated with different metabolic pathways. In clinical cases, liver pathology resulting from overdoses is most often as a result of acetaminophen (APAP) or alcohol (ethanol). Therefore, we have studied and compared the metabolic state of hepatocytes in various experimental models of APAP and ethanol hepatotoxicity. We have determined the potential diagnostic criteria including the pathologically altered metabolism of the hepatocytes in the early stages of toxic damage, including pronounced changes in the contribution from the bound form of NAD(P)H. In contrast to the MFCs, the changes in the metabolic state of hepatocytes in the ex vivo models are, to a greater extent, associated with compensatory processes. Thus, MFCs in combination with FLIM can be applied as an effective tool set for the express modeling and diagnosis of hepatotoxicity in clinics.
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Affiliation(s)
- Svetlana Rodimova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia; (V.E.); (M.K.); (V.Z.); (E.Z.); (D.K.)
- Department of Biophysics, N.I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Vadim Elagin
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia; (V.E.); (M.K.); (V.Z.); (E.Z.); (D.K.)
| | - Maria Karabut
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia; (V.E.); (M.K.); (V.Z.); (E.Z.); (D.K.)
| | - Irina Koryakina
- School of Physics and Engineering, ITMO University, 9 Lomonosova St., 191002 St. Petersburg, Russia; (I.K.); (M.Z.)
| | - Alexander Timin
- Research School of Chemical and Biomedical Engineering, National Research Tomsk Polytechnic University, 30 Lenin Ave., 634034 Tomsk, Russia;
- Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 29 Polytechnicheskaya St., 194064 St. Petersburg, Russia
| | - Vladimir Zagainov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia; (V.E.); (M.K.); (V.Z.); (E.Z.); (D.K.)
- The Volga District Medical Centre of Federal Medical and Biological Agency, 14 Ilinskaya St., 603000 Nizhny Novgorod, Russia
| | - Mikhail Zyuzin
- School of Physics and Engineering, ITMO University, 9 Lomonosova St., 191002 St. Petersburg, Russia; (I.K.); (M.Z.)
| | - Elena Zagaynova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia; (V.E.); (M.K.); (V.Z.); (E.Z.); (D.K.)
- Department of Biophysics, N.I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
| | - Daria Kuznetsova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603000 Nizhny Novgorod, Russia; (V.E.); (M.K.); (V.Z.); (E.Z.); (D.K.)
- Department of Biophysics, N.I. Lobachevsky Nizhny Novgorod National Research State University, 23 Gagarina Ave., 603022 Nizhny Novgorod, Russia
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16
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Uddin SMA, Chowdhury SS, Kabir E. Numerical Analysis of a Highly Sensitive Surface Plasmon Resonance Sensor for SARS-CoV-2 Detection. PLASMONICS (NORWELL, MASS.) 2021; 16:2025-2037. [PMID: 34054377 PMCID: PMC8144697 DOI: 10.1007/s11468-021-01455-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 05/03/2021] [Indexed: 05/27/2023]
Abstract
In this paper, we propose a surface plasmon resonance (SPR) structure based on Kretschmann configuration incorporating layers of silicon and BaTiO3 on top of Ag for real-time detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using thiol-tethered DNA as a ligand. Extensive numerical analysis based on transfer matrix theory as well as finite-difference time-domain (FDTD) technique has been performed to characterize the sensor response considering sensitivity, full width at half maxima, and minimum reflection. About 7.6 times enhanced sensitivity has been obtained using the proposed architecture for SARS-CoV-2 detection, compared to the basic Kretschmann configuration. Notably, the structure provides consistent enhancement over other competitive SPR structures for both angular and wavelength interrogations with a figure-of-merit of 692.28. Additionally, we repeated simulations for various ligate-ligand pairs to assess the range of applicability and robust performance improvement has been observed. As a result, the proposed sensor design provides a suitable configuration for highly sensitive, rapid, noninvasive biosensing which can be useful if adopted in experimental sensing protocols.
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Affiliation(s)
| | | | - Ehsan Kabir
- Department of EEE, Bangladesh University of Engineering and Technology, Dhaka, 1205 Bangladesh
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17
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High-speed compressed-sensing fluorescence lifetime imaging microscopy of live cells. Proc Natl Acad Sci U S A 2021; 118:2004176118. [PMID: 33431663 DOI: 10.1073/pnas.2004176118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We present high-resolution, high-speed fluorescence lifetime imaging microscopy (FLIM) of live cells based on a compressed sensing scheme. By leveraging the compressibility of biological scenes in a specific domain, we simultaneously record the time-lapse fluorescence decay upon pulsed laser excitation within a large field of view. The resultant system, referred to as compressed FLIM, can acquire a widefield fluorescence lifetime image within a single camera exposure, eliminating the motion artifact and minimizing the photobleaching and phototoxicity. The imaging speed, limited only by the readout speed of the camera, is up to 100 Hz. We demonstrated the utility of compressed FLIM in imaging various transient dynamics at the microscopic scale.
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18
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Joly J, Hudik E, Lecart S, Roos D, Verkuijlen P, Wrona D, Siler U, Reichenbach J, Nüsse O, Dupré-Crochet S. Membrane Dynamics and Organization of the Phagocyte NADPH Oxidase in PLB-985 Cells. Front Cell Dev Biol 2020; 8:608600. [PMID: 33365312 PMCID: PMC7751761 DOI: 10.3389/fcell.2020.608600] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/20/2020] [Indexed: 11/13/2022] Open
Abstract
Neutrophils are the first cells recruited at the site of infections, where they phagocytose the pathogens. Inside the phagosome, pathogens are killed by proteolytic enzymes that are delivered to the phagosome following granule fusion, and by reactive oxygen species (ROS) produced by the NADPH oxidase. The NADPH oxidase complex comprises membrane proteins (NOX2 and p22phox), cytoplasmic subunits (p67phox, p47phox, and p40phox) and the small GTPase Rac. These subunits assemble at the phagosomal membrane upon phagocytosis. In resting neutrophils the catalytic subunit NOX2 is mainly present at the plasma membrane and in the specific granules. We show here that NOX2 is also present in early and recycling endosomes in human neutrophils and in the neutrophil-like cell line PLB-985 expressing GFP-NOX2. In the latter cells, an increase in NOX2 at the phagosomal membrane was detected by live-imaging after phagosome closure, probably due to fusion of endosomes with the phagosome. Using super-resolution microscopy in PLB-985 WT cells, we observed that NOX2 forms discrete clusters in the plasma membrane. The number of clusters increased during frustrated phagocytosis. In PLB-985NCF1ΔGT cells that lack p47phox and do not assemble a functional NADPH oxidase, the number of clusters remained stable during phagocytosis. Our data suggest a role for p47phox and possibly ROS production in NOX2 recruitment at the phagosome.
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Affiliation(s)
- Jérémy Joly
- Université Paris-Saclay, CNRS U8000, Institut de Chimie Physique, Orsay, France
| | - Elodie Hudik
- Université Paris-Saclay, CNRS U8000, Institut de Chimie Physique, Orsay, France
| | - Sandrine Lecart
- Light Microscopy Core Facility, Imagerie-Gif, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Dirk Roos
- Sanquin Research and Landsteiner Laboratory, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Paul Verkuijlen
- Sanquin Research and Landsteiner Laboratory, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Dominik Wrona
- Division of Gene and Cell Therapy, Institute for Regenerative Medecine, University of Zurich, Zurich, Switzerland
| | - Ulrich Siler
- Division of Gene and Cell Therapy, Institute for Regenerative Medecine, University of Zurich, Zurich, Switzerland
| | - Janine Reichenbach
- Division of Gene and Cell Therapy, Institute for Regenerative Medecine, University of Zurich, Zurich, Switzerland
| | - Oliver Nüsse
- Université Paris-Saclay, CNRS U8000, Institut de Chimie Physique, Orsay, France
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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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20
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Gul B, Ashraf S, Khan S, Nisar H, Ahmad I. Cell refractive index: Models, insights, applications and future perspectives. Photodiagnosis Photodyn Ther 2020; 33:102096. [PMID: 33188939 DOI: 10.1016/j.pdpdt.2020.102096] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 01/09/2023]
Abstract
Cell refractive index (RI) is an intrinsic optical parameter that governs the propagation of light (i.e., scattering and absorption) in the cell matrix. The RI of cell is sensitively correlated with its mass distribution and thereby has the capability to provide important insights for diverse biological models. Herein, we review the cell refractive index and the fundamental models for measurement of cell RI, summarize the published RI data of cell and cell organelles and discuss the associated insights. Illustrative applications of cell RI in cell biology are also outlined. Finally, future research trends and applications of cell RI, including novel imaging techniques, reshaping flow cytometry and microfluidic platforms for single cell manipulation are discussed. The rapid technological advances in optical imaging integrated with microfluidic regime seems to enable deeper understanding of subcellular dynamics with high spatio-temporal resolution in real time.
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Affiliation(s)
- Banat Gul
- Department of Basic Sciences, Military College of Engineering, National University of Science and Technology (NUST), Islamabad, Pakistan
| | - Sumara Ashraf
- Department of Physics, The Women University Multan, Pakistan
| | - Shamim Khan
- Department of Physics, Islamia College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Hasan Nisar
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Germany
| | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan.
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21
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Dual-Color Metal-Induced Energy Transfer (MIET) Imaging for Three-Dimensional Reconstruction of Nuclear Envelope Architecture. Methods Mol Biol 2020. [PMID: 32681482 DOI: 10.1007/978-1-0716-0763-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The nuclear envelope, comprising the inner and the outer nuclear membrane, separates the nucleus from the cytoplasm and plays a key role in cellular functions. Nuclear pore complexes (NPCs) are embedded in the nuclear envelope and control transport of macromolecules between the two compartments. Recently, it has been shown that the axial distance between the inner nuclear membrane and the cytoplasmic side of the NPC can be measured using dual-color metal-induced energy transfer (MIET). This chapter focuses on experimental aspects of this method and discusses the details of data analysis.
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22
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Davidson NM, Gallimore PJ, Bateman B, Ward AD, Botchway SW, Kalberer M, Kuimova MK, Pope FD. Measurement of the fluorescence lifetime of GFP in high refractive index levitated droplets using FLIM. Phys Chem Chem Phys 2020; 22:14704-14711. [PMID: 32573569 DOI: 10.1039/c9cp06395a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Green fluorescent protein (GFP) is a widely used fluorescent probe in the life sciences and biosciences due to its high quantum yield and extinction coefficient, and its ability to bind to biological systems of interest. This study measures the fluorescence lifetime of GFP in sucrose/water solutions of known molarity in order to determine the refractive index dependent lifetime of GFP. A range of refractive indices from 1.43-1.53 were probed by levitating micron sized droplets composed of water/sucrose/GFP in an optical trap under well-constrained conditions of relative humidity. This setup allows for the first reported measurements of the fluorescence lifetime of GFP at refractive indices greater than 1.46. The results obtained at refractive indices less than 1.46 show good agreement with previous studies. Further experiments that trapped droplets of deionised water containing GFP allowed the hygroscopic properties of GFP to be measured. GFP is found to be mildly hygroscopic by mass, but the high ratio of molecular masses of GFP to water (ca. 1500 : 1) signifies that water uptake is large on a per-mole basis. Hygroscopic properties are verified using brightfield microscope imaging, of GFP droplets at low and high relative humidity, by measuring the humidity dependent droplet size. In addition, this experiment allowed the refractive index of pure GFP to be estimated for the first time (1.72 ± 0.07). This work provides reference data for future experiments involving GFP, especially for those conducted in high refractive index media. The work also demonstrates that GFP can be used as a probe for aerosol studies, which require determination of the refractive index of the aerosol of any shape.
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Affiliation(s)
- N M Davidson
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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23
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Sapermsap N, Li DDU, Al-Hemedawi R, Li Y, Yu J, Birch DJS, Chen Y. A rapid analysis platform for investigating the cellular locations of bacteria using two-photon fluorescence lifetime imaging microscopy. Methods Appl Fluoresc 2020; 8:034001. [DOI: 10.1088/2050-6120/ab854e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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24
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Pliss A, Prasad PN. High resolution mapping of subcellular refractive index by Fluorescence Lifetime Imaging: a next frontier in quantitative cell science? Methods Appl Fluoresc 2020; 8:032001. [PMID: 32235079 DOI: 10.1088/2050-6120/ab8571] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Intracellular refractive index (RI) is an essential biophysical parameter, which best represents the mass and the distribution of proteins in the cell interior, including high-density accumulations in membraneless organelles. For RI measurements, a number of sophisticated techniques have been developed; however most of the new approaches are either insufficiently sensitive to intracellular variations of proteins distribution or are not compatible with live cell studies. Here, we outline the fluorescence lifetime imaging (FLIM) strategy for high resolution mapping of subcellular RI. We provide an example of our recent studies in which we utilize FLIM for measurements and monitoring of local RI in the major membraneless organelles within live cultured cells.
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25
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Galeano Niño JL, Tay SS, Tearle JLE, Xie J, Govendir MA, Kempe D, Mazalo J, Drew AP, Colakoglu F, Kummerfeld SK, Proud CG, Biro M. The Lifeact-EGFP mouse is a translationally controlled fluorescent reporter of T cell activation. J Cell Sci 2020; 133:jcs238014. [PMID: 32041902 DOI: 10.1242/jcs.238014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 02/04/2020] [Indexed: 12/11/2022] Open
Abstract
It has become increasingly evident that T cell functions are subject to translational control in addition to transcriptional regulation. Here, by using live imaging of CD8+ T cells isolated from the Lifeact-EGFP mouse, we show that T cells exhibit a gain in fluorescence intensity following engagement of cognate tumour target cells. The GFP signal increase is governed by Erk1/2-dependent distal T cell receptor (TCR) signalling and its magnitude correlates with IFN-γ and TNF-α production, which are hallmarks of T cell activation. Enhanced fluorescence was due to increased translation of Lifeact-EGFP protein, without an associated increase in its mRNA. Activation-induced gains in fluorescence were also observed in naïve and CD4+ T cells from the Lifeact-EGFP reporter, and were readily detected by both flow cytometry and live cell microscopy. This unique, translationally controlled reporter of effector T cell activation simultaneously enables tracking of cell morphology, F-actin dynamics and activation state in individual migrating T cells. It is a valuable addition to the limited number of reporters of T cell dynamics and activation, and opens the door to studies of translational activity and heterogeneities in functional T cell responses in situ.
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Affiliation(s)
- Jorge Luis Galeano Niño
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Szun S Tay
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Jacqueline L E Tearle
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Jianling Xie
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia
| | - Matt A Govendir
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Daryan Kempe
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Jessica Mazalo
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Alexander P Drew
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Feyza Colakoglu
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Sarah K Kummerfeld
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Christopher G Proud
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia
- School of Biological Sciences, University of Adelaide, Frome Road, Adelaide
| | - Maté Biro
- EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, NSW 2052, Australia
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26
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Audugé N, Padilla-Parra S, Tramier M, Borghi N, Coppey-Moisan M. Chromatin condensation fluctuations rather than steady-state predict chromatin accessibility. Nucleic Acids Res 2020; 47:6184-6194. [PMID: 31081027 PMCID: PMC6614833 DOI: 10.1093/nar/gkz373] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/24/2019] [Accepted: 05/07/2019] [Indexed: 01/16/2023] Open
Abstract
Chromatin accessibility to protein factors is critical for genome activities. However, the dynamic properties of chromatin higher-order structures that regulate its accessibility are poorly understood. Here, we took advantage of the microenvironment sensitivity of the fluorescence lifetime of EGFP-H4 histone incorporated in chromatin to map in the nucleus of live cells the dynamics of chromatin condensation and its direct interaction with a tail acetylation recognition domain (the double bromodomain module of human TAFII250, dBD). We reveal chromatin condensation fluctuations supported by mechanisms fundamentally distinct from that of condensation. Fluctuations are spontaneous, yet their amplitudes are affected by their sub-nuclear localization and by distinct and competing mechanisms dependent on histone acetylation, ATP and both. Moreover, we show that accessibility of acetylated histone H4 to dBD is not restricted by chromatin condensation nor predicted by acetylation, rather, it is predicted by chromatin condensation fluctuations.
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Affiliation(s)
- Nicolas Audugé
- Institut Jacques Monod UMR 7592, Université de Paris - Centre National de la Recherche Scientifique, Paris, France
| | - Sergi Padilla-Parra
- Institut Jacques Monod UMR 7592, Université de Paris - Centre National de la Recherche Scientifique, Paris, France
| | - Marc Tramier
- Institut Jacques Monod UMR 7592, Université de Paris - Centre National de la Recherche Scientifique, Paris, France
| | - Nicolas Borghi
- Institut Jacques Monod UMR 7592, Université de Paris - Centre National de la Recherche Scientifique, Paris, France
| | - Maïté Coppey-Moisan
- Institut Jacques Monod UMR 7592, Université de Paris - Centre National de la Recherche Scientifique, Paris, France
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27
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Hung ST, Mukherjee S, Jimenez R. Enrichment of rare events using a multi-parameter high throughput microfluidic droplet sorter. LAB ON A CHIP 2020; 20:834-843. [PMID: 31974539 PMCID: PMC7135947 DOI: 10.1039/c9lc00790c] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
High information content analysis, enrichment, and selection of rare events from a large population are of great importance in biological and biomedical research. The fluorescence lifetime of a fluorophore, a photophysical property which is independent of and complementary to fluorescence intensity, has been incorporated into various imaging and sensing techniques through microscopy, flow cytometry and droplet microfluidics. However, the throughput of fluorescence lifetime activated droplet sorting is orders of magnitude lower than that of fluorescence activated cell sorting, making it unattractive for applications such as directed evolution of enzymes, despite its highly effective compartmentalization of library members. We developed a microfluidic sorter capable of selecting fluorophores based on fluorescence lifetime and brightness at two excitation and emission colors at a maximum droplet rate of 2.5 kHz. We also present a novel selection strategy for efficiently analyzing and/or enriching rare fluorescent members from a large population which capitalizes on the Poisson distribution of analyte encapsulation into droplets. The effectiveness of the droplet sorter and the new selection strategy are demonstrated by enriching rare populations from a ∼108-member site-directed mutagenesis library of fluorescent proteins expressed in bacteria. This selection strategy can in principle be employed on many droplet sorting platforms, and thus can potentially impact broad areas of science where analysis and enrichment of rare events is needed.
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Affiliation(s)
- Sheng-Ting Hung
- JILA, NIST and University of Colorado, Boulder, Colorado 80309, USA.
| | - Srijit Mukherjee
- JILA, NIST and University of Colorado, Boulder, Colorado 80309, USA. and Department of Chemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Ralph Jimenez
- JILA, NIST and University of Colorado, Boulder, Colorado 80309, USA. and Department of Chemistry, University of Colorado, Boulder, Colorado 80309, USA
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28
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The NADPH Oxidase and the Phagosome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1246:153-177. [DOI: 10.1007/978-3-030-40406-2_9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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29
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Zeng SL, Grabowska D, Shahverdi K, Sudlow LC, Achilefu S, Berezin MY. Fluorescence lifetime imaging reveals heterogeneous functional distribution of eGFP expressed in Xenopus oocytes. Methods Appl Fluoresc 2019; 8:015001. [PMID: 31658452 DOI: 10.1088/2050-6120/ab51f8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The oocytes from Xenopus laevis are well known for their polarity, presenting a distinct animal and vegetal pole. Other heterogeneities are less known. To study the heterogeneity of the Xenopus oocyte, we expressed eGFP and analyzed the protein distribution with fluorescence lifetime microscopy. The vegetal pole exhibited higher levels of fluorescence, than the animal pole. However, the fluorescence lifetimes between the two areas were indistinguishable, suggesting similar environments. In contrast, we observed a substantial and gradual decrease in the fluorescence lifetime from 2.9 ns to 2.6 ns as slices approached the periphery. This has an important implication for future oocyte studies as it demonstrates the environment inside the oocyte is not uniform and might affect the fluorescence intensity. As a result, it cannot be assumed that the observed fluorescence intensity reflects the expression of the proteins but might reflect the environment within the oocyte.
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Affiliation(s)
- Steven L Zeng
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, United States of America
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30
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Welsh JA, Horak P, Wilkinson JS, Ford VJ, Jones JC, Smith D, Holloway JA, Englyst NA. FCM PASS Software Aids Extracellular Vesicle Light Scatter Standardization. Cytometry A 2019; 97:569-581. [PMID: 31250561 DOI: 10.1002/cyto.a.23782] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/04/2019] [Accepted: 04/16/2019] [Indexed: 01/29/2023]
Abstract
The study of extracellular vesicles (EVs) is a rapidly growing field due to their great potential in many areas of clinical medicine including diagnostics, prognostics, theranostics, and therapeutics. Flow cytometry is currently one of the most popular methods of analyzing EVs due to it being a high-throughput, multiparametric technique, that is readily available in the majority of research labs. Despite its wide use, few commercial flow cytometers are designed specifically for the detection of EVs. Many flow cytometers used for EV analysis are working at their detection limits and are unable to detect the majority of EVs. Currently, very little standardization exists for EV flow cytometry, which is an issue because flow cytometers vary considerably in the way they collect scattered or fluorescent light from particles being interrogated. This makes published research hard to interpret, compare, and in some cases, impossible to reproduce. Here we demonstrate a method of flow cytometer light scatter standardization, utilizing flow cytometer postacquisition analysis software (FCMPASS ). FCMPASS is built upon Mie theory and enables the approximation of flow cytometer geometric parameters either by analyzing beads of known diameter and refractive index or by inputting the collection angle if known. The software is then able to create a scatter-diameter curve and scatter-refractive index curve that enables researchers to convert scattering data and instrument sensitivity into standardized units. Furthermore, with the correct controls, light scatter data can be converted to diameter distributions or refractive index distributions. FCMPASS therefore offers a freely available and ergonomic method of standardizing and further extending EV characterization using flow cytometry.
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Affiliation(s)
- Joshua A Welsh
- Faculty of Medicine, University of Southampton, Southampton, UK.,Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Peter Horak
- Optoelectronics Research Centre, University of Southampton, Southampton, UK
| | - James S Wilkinson
- Optoelectronics Research Centre, University of Southampton, Southampton, UK
| | - Verity J Ford
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - Jennifer C Jones
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - David Smith
- Faculty of Medicine, University of Southampton, Southampton, UK.,Anaesthetics Department, University Hospital Southampton, Southampton UK
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31
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Diattenuation Imaging reveals different brain tissue properties. Sci Rep 2019; 9:1939. [PMID: 30760789 PMCID: PMC6374401 DOI: 10.1038/s41598-019-38506-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 12/27/2018] [Indexed: 12/14/2022] Open
Abstract
When transmitting polarised light through histological brain sections, different types of diattenuation (polarisation-dependent attenuation of light) can be observed: In some brain regions, the light is minimally attenuated when it is polarised parallel to the nerve fibres (referred to as D+), in others, it is maximally attenuated (referred to as D−). The underlying mechanisms of these effects and their relationship to tissue properties were so far unknown. Here, we demonstrate in experimental studies that diattenuation of both types D+ and D− can be observed in brain tissue samples from different species (rodent, monkey, and human) and that the strength and type of diattenuation depend on the nerve fibre orientations. By combining finite-difference time-domain simulations and analytical modelling, we explain the observed diattenuation effects and show that they are caused both by anisotropic absorption (dichroism) and by anisotropic light scattering. Our studies demonstrate that the diattenuation signal depends not only on the nerve fibre orientations but also on other brain tissue properties like tissue homogeneity, fibre size, and myelin sheath thickness. This allows to use the diattenuation signal to distinguish between brain regions with different tissue properties and establishes Diattenuation Imaging as a valuable imaging technique.
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32
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Cycles of protein condensation and discharge in nuclear organelles studied by fluorescence lifetime imaging. Nat Commun 2019; 10:455. [PMID: 30692529 PMCID: PMC6349932 DOI: 10.1038/s41467-019-08354-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 01/03/2019] [Indexed: 02/07/2023] Open
Abstract
Nuclear organelles are viscous droplets, created by concentration-dependent condensation and liquid–liquid phase separation of soluble proteins. Nuclear organelles have been actively investigated for their role in cellular regulation and disease. However, these studies are highly challenging to perform in live cells, and therefore, their physico-chemical properties are still poorly understood. In this study, we describe a fluorescence lifetime imaging approach for real-time monitoring of protein condensation in nuclear organelles of live cultured cells. This approach unravels surprisingly large cyclic changes in concentration of proteins in major nuclear organelles including nucleoli, nuclear speckles, Cajal bodies, as well as in the clusters of heterochromatin. Remarkably, protein concentration changes are synchronous for different organelles of the same cells. We propose a molecular mechanism responsible for synchronous accumulations of proteins in the nuclear organelles. This mechanism can serve for general regulation of cellular metabolism and contribute to coordination of gene expression. Studying the condensation of proteins into membraneless organelles in live cells is highly challenging. Here the authors develop a fluorescence lifetime imaging approach to monitor the condensation of proteins in nuclear organelles and report coordinated and cyclic changes in several nuclear organelles.
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33
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Aubret A, Orrit M, Kulzer F. Understanding Local‐Field Correction Factors in the Framework of the Onsager−Böttcher Model. Chemphyschem 2019; 20:345-355. [DOI: 10.1002/cphc.201800923] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/07/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Antoine Aubret
- University of California San DiegoUCSD)Physics Department 9500 Gilman Dr. La Jolla, CA 92093-0319 USA
| | - Michel Orrit
- Molecular Nano-Optics and Spins (MoNOS)Huygens LaboratoryLeiden University P.O. Box 9504 2300 RA Leiden The Netherlands
| | - Florian Kulzer
- Institut Lumière MatièreCNRS UMR5306Université Lyon 1Université de Lyon 69622 Villeurbanne CEDEX France
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34
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Loozen GB, Caro J. On-chip optical trapping of extracellular vesicles using box-shaped composite SiO 2-Si 3N 4 waveguides. OPTICS EXPRESS 2018; 26:26985-27000. [PMID: 30469775 DOI: 10.1364/oe.26.026985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The application of on-chip optical trapping and Raman spectroscopy using a dual-waveguide trap has so far been limited to relatively big synthetic and biological particles (e.g., polystyrene beads and blood cells). Here, from simulations, we present the capabilities of dual-waveguide traps built from composite SiO2-Si3N4 waveguides for optical trapping of extracellular vesicles (EVs). EVs, tiny cell-derived particles of size in the range 30-1000 nm, strongly attract attention as potential biomarkers for cancer. EVs are hard to trap, because of their smallness and low index contract w.r.t. water. This poses a challenge for on-chip trapping. From finite-difference time-domain simulations we obtain the narrow beam emitted from the waveguide facet into water, for λ = 785 nm. For a pair of such beams, in a counter-propagating geometry and for facet separations of 5, 10 and 15 µm, we derive the inter-facet optical field, which has a characteristic interference pattern with hot spots for trapping, and calculate the optical force exerted on EVs of size in the range 50-1000 nm, as a function of EV position. We use two refractive index models for the EV optical properties. Integration of the force curves leads to the trapping potentials, which are well-shaped in the transverse and oscillatory in the longitudinal direction. By applying Ashkin's criterion, the conditions for stable trapping are established, the central result of this work. Very small EVs can be stably trapped with the traps by applying a power also suitable for Raman spectroscopy, down to a smallest EV diameter of 115 nm. We thus argue that this dual-waveguide trap is a promising lab-on-a-chip device with clinical relevance for diagnosis of cancer.
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Kristoffersen AS, Erga SR, Hamre B, Frette Ø. Testing Fluorescence Lifetime Standards using Two-Photon Excitation and Time-Domain Instrumentation: Fluorescein, Quinine Sulfate and Green Fluorescent Protein. J Fluoresc 2018; 28:1065-1073. [PMID: 30046998 PMCID: PMC6153725 DOI: 10.1007/s10895-018-2270-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 07/20/2018] [Indexed: 11/30/2022]
Abstract
It is essential for everyone working with experimental science to be certain that their instruments produce reliable results, and for fluorescence lifetime experiments, information about fluorescence lifetime standards is crucial. A large part of the literature on lifetime standards dates back to the 1970s and 1980s, and the use of newer and faster measuring devices may deem these results unreliable. We have tested the three commonly used fluorophores fluorescein, quinine sulfate and green fluorescent protein for their suitability to serve as lifetime standards, especially to be used with two-photon excitation measurements in the time-domain. We measured absorption and emission spectra for the fluorophores to determine optimal wavelengths to use for excitation and detector settings. Fluorescence lifetimes were measured for different concentrations, ranging from 10− 3 − 10− 5 M, as well as for various solvents. Fluorescein was soluble in both ethanol, methanol and sulfuric acid, while quinine sulfate was only soluble in sulfuric acid. Green fluorescent protein was prepared in a commercial Tris-HCl, EDTA solution, and all three fluorophores produced stable lifetime results with low uncertainties. No siginificant variation with concentration was measured for any of the fluorophores, and all showed single-exponential decays. All lifetime measurements were carried out using two-photon excitation and lifetime data was obtained in the time-domain using time-correlated single-photon counting.
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Affiliation(s)
- Arne S Kristoffersen
- Department of Physics and Technology, University of Bergen, P.O. Box 7803, Bergen, N-5020, Norway.
| | - Svein R Erga
- Department of Biological Sciences, University of Bergen, P.O. Box 7803, Bergen, N-5020, Norway
| | - Børge Hamre
- Department of Physics and Technology, University of Bergen, P.O. Box 7803, Bergen, N-5020, Norway
| | - Øyvind Frette
- Department of Physics and Technology, University of Bergen, P.O. Box 7803, Bergen, N-5020, Norway
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Varga Z, van der Pol E, Pálmai M, Garcia-Diez R, Gollwitzer C, Krumrey M, Fraikin JL, Gasecka A, Hajji N, van Leeuwen TG, Nieuwland R. Hollow organosilica beads as reference particles for optical detection of extracellular vesicles. J Thromb Haemost 2018; 16:S1538-7836(22)02214-0. [PMID: 29877049 DOI: 10.1111/jth.14193] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Indexed: 11/30/2022]
Abstract
Essentials Standardization of extracellular vesicle (EV) measurements by flow cytometry needs improvement. Hollow organosilica beads were prepared, characterized, and tested as reference particles. Light scattering properties of hollow beads resemble that of platelet-derived EVs. Hollow beads are ideal reference particles to standardize scatter flow cytometry research on EVs. SUMMARY Background The concentration of extracellular vesicles (EVs) in body fluids is a promising biomarker for disease, and flow cytometry remains the clinically most applicable method to identify the cellular origin of single EVs in suspension. To compare concentration measurements of EVs between flow cytometers, solid polystyrene reference beads and EVs were distributed in the first ISTH-organized interlaboratory comparison studies. The beads were used to set size gates based on light scatter, and the concentration of EVs was measured within the size gates. However, polystyrene beads lead to false size determination of EVs, owing to the mismatch in refractive index between beads and EVs. Moreover, polystyrene beads gate different EV sizes on different flow cytometers. Objective To prepare, characterize and test hollow organosilica beads (HOBs) as reference beads to set EV size gates in flow cytometry investigations. Methods HOBs were prepared with a hard template sol-gel method, and extensively characterized for morphology, size, and colloidal stability. The applicability of HOBs as reference particles was investigated by flow cytometry with HOBs and platelet-derived EVs. Results HOBs proved to be monodisperse with a homogeneous shell thickness. Two-angle light-scattering measurements by flow cytometry confirmed that HOBs have light-scattering properties similar to those of platelet-derived EVs. Conclusions Because the structure and light-scattering properties HOBs resemble those of EVs, HOBs with a given size will gate EVs of the same size. Therefore, HOBs are ideal reference beads with which to standardize optical measurements of the EV concentration within a predefined size range.
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Affiliation(s)
- Z Varga
- Biological Nanochemistry Research Group, Institute of Materials and Environmental Chemistry, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - E van der Pol
- Laboratory of Experimental Clinical Chemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
- Department of Biomedical Engineering and Physics, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
- Vesicle Observation Center, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
| | - M Pálmai
- Biological Nanochemistry Research Group, Institute of Materials and Environmental Chemistry, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - R Garcia-Diez
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - C Gollwitzer
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - M Krumrey
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | | | - A Gasecka
- Laboratory of Experimental Clinical Chemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
- Vesicle Observation Center, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
- 1st Chair and Department of Cardiology, Medical University of Warsaw, Warsaw, Poland
| | - N Hajji
- Laboratory of Experimental Clinical Chemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
| | - T G van Leeuwen
- Department of Biomedical Engineering and Physics, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
- Vesicle Observation Center, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
| | - R Nieuwland
- Laboratory of Experimental Clinical Chemistry, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
- Vesicle Observation Center, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
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Funane T, Hou SS, Zoltowska KM, van Veluw SJ, Berezovska O, Kumar ATN, Bacskai BJ. Selective plane illumination microscopy (SPIM) with time-domain fluorescence lifetime imaging microscopy (FLIM) for volumetric measurement of cleared mouse brain samples. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:053705. [PMID: 29864842 PMCID: PMC6910582 DOI: 10.1063/1.5018846] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 04/24/2018] [Indexed: 05/02/2023]
Abstract
We have developed an imaging technique which combines selective plane illumination microscopy with time-domain fluorescence lifetime imaging microscopy (SPIM-FLIM) for three-dimensional volumetric imaging of cleared mouse brains with micro- to mesoscopic resolution. The main features of the microscope include a wavelength-adjustable pulsed laser source (Ti:sapphire) (near-infrared) laser, a BiBO frequency-doubling photonic crystal, a liquid chamber, an electrically focus-tunable lens, a cuvette based sample holder, and an air (dry) objective lens. The performance of the system was evaluated with a lifetime reference dye and micro-bead phantom measurements. Intensity and lifetime maps of three-dimensional human embryonic kidney (HEK) cell culture samples and cleared mouse brain samples expressing green fluorescent protein (GFP) (donor only) and green and red fluorescent protein [positive Förster (fluorescence) resonance energy transfer] were acquired. The results show that the SPIM-FLIM system can be used for sample sizes ranging from single cells to whole mouse organs and can serve as a powerful tool for medical and biological research.
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Affiliation(s)
- Tsukasa Funane
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Steven S Hou
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Katarzyna Marta Zoltowska
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Susanne J van Veluw
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Oksana Berezovska
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Anand T N Kumar
- Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA
| | - Brian J Bacskai
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
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Application of Fluorescence Lifetime Imaging (FLIM) to Measure Intracellular Environments in a Single Cell. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1035:121-133. [PMID: 29080134 DOI: 10.1007/978-3-319-67358-5_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Fluorescence lifetime imaging (FLIM) has now been used in many bioscience fields, which comes from the quantification of fluorescence lifetime. The procedure for obtaining lifetime images is very similar to that used in fluorescence microscopy. However, obtaining reliable lifetime images requires an understanding of the theory of fluorescence lifetime, principle of FLIM systems, and evaluation procedure of intracellular environments. In this chapter, the materials, methods, and notes on FLIM measurements have been described, in conjunction with a brief explanation of the background of FLIM.
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Model MA, Petruccelli JC. Intracellular Macromolecules in Cell Volume Control and Methods of Their Quantification. CURRENT TOPICS IN MEMBRANES 2018; 81:237-289. [DOI: 10.1016/bs.ctm.2018.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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40
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Chizhik AM, Ruhlandt D, Pfaff J, Karedla N, Chizhik AI, Gregor I, Kehlenbach RH, Enderlein J. Three-Dimensional Reconstruction of Nuclear Envelope Architecture Using Dual-Color Metal-Induced Energy Transfer Imaging. ACS NANO 2017; 11:11839-11846. [PMID: 28921961 DOI: 10.1021/acsnano.7b04671] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The nuclear envelope, comprising the inner and the outer nuclear membrane, separates the nucleus from the cytoplasm and plays a key role in cellular functions. Nuclear pore complexes (NPCs), which are embedded in the nuclear envelope, control transport of macromolecules between the two compartments. Here, using dual-color metal-induced energy transfer (MIET), we determine the axial distance between Lap2β and Nup358 as markers for the inner nuclear membrane and the cytoplasmic side of the NPC, respectively. Using MIET imaging, we reconstruct the 3D profile of the nuclear envelope over the whole basal area, with an axial resolution of a few nanometers. This result demonstrates that optical microscopy can achieve nanometer axial resolution in biological samples and without recourse to complex interferometric approaches.
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Affiliation(s)
- Anna M Chizhik
- Third Institute of Physics, University of Göttingen , 37077 Göttingen, Germany
| | - Daja Ruhlandt
- Third Institute of Physics, University of Göttingen , 37077 Göttingen, Germany
| | - Janine Pfaff
- Universitätsmedizin Göttingen, University of Göttingen, Department of Molecular Biology, GZMB , 37073 Göttingen, Germany
| | - Narain Karedla
- Third Institute of Physics, University of Göttingen , 37077 Göttingen, Germany
| | - Alexey I Chizhik
- Third Institute of Physics, University of Göttingen , 37077 Göttingen, Germany
| | - Ingo Gregor
- Third Institute of Physics, University of Göttingen , 37077 Göttingen, Germany
| | - Ralph H Kehlenbach
- Universitätsmedizin Göttingen, University of Göttingen, Department of Molecular Biology, GZMB , 37073 Göttingen, Germany
| | - Jörg Enderlein
- Third Institute of Physics, University of Göttingen , 37077 Göttingen, Germany
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41
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Bohannon KP, Holz RW, Axelrod D. Refractive Index Imaging of Cells with Variable-Angle Near-Total Internal Reflection (TIR) Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:978-988. [PMID: 28918767 PMCID: PMC7790292 DOI: 10.1017/s1431927617012570] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The refractive index in the interior of single cells affects the evanescent field depth in quantitative studies using total internal reflection (TIR) fluorescence, but often that index is not well known. We here present method to measure and spatially map the absolute index of refraction in a microscopic sample, by imaging a collimated light beam reflected from the substrate/buffer/cell interference at variable angles of incidence. Above the TIR critical angle (which is a strong function of refractive index), the reflection is 100%, but in the immediate sub-critical angle zone, the reflection intensity is a very strong ascending function of incidence angle. By analyzing the angular position of that edge at each location in the field of view, the local refractive index can be estimated. In addition, by analyzing the steepness of the edge, the distance-to-substrate can be determined. We apply the technique to liquid calibration samples, silica beads, cultured Chinese hamster ovary cells, and primary culture chromaffin cells. The optical technique suffers from decremented lateral resolution, scattering, and interference artifacts. However, it still provides reasonable results for both refractive index (~1.38) and for distance-to-substrate (~150 nm) for the cells, as well as a lateral resolution to about 1 µm.
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Affiliation(s)
- Kevin P. Bohannon
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ronald W. Holz
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Daniel Axelrod
- Departments of Physics and LSA Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
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42
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Near-Membrane Refractometry Using Supercritical Angle Fluorescence. Biophys J 2017; 112:1940-1948. [PMID: 28494964 DOI: 10.1016/j.bpj.2017.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/08/2017] [Accepted: 03/13/2017] [Indexed: 12/20/2022] Open
Abstract
Total internal reflection fluorescence (TIRF) microscopy and its variants are key technologies for visualizing the dynamics of single molecules or organelles in live cells. Yet truly quantitative TIRF remains problematic. One unknown hampering the interpretation of evanescent-wave excited fluorescence intensities is the undetermined cell refractive index (RI). Here, we use a combination of TIRF excitation and supercritical angle fluorescence emission detection to directly measure the average RI in the "footprint" region of the cell during image acquisition. Our RI measurement is based on the determination on a back-focal plane image of the critical angle separating evanescent and far-field fluorescence emission components. We validate our method by imaging mouse embryonic fibroblasts and BON cells. By targeting various dyes and fluorescent-protein chimeras to vesicles, the plasma membrane, as well as mitochondria and the endoplasmic reticulum, we demonstrate local RI measurements with subcellular resolution on a standard TIRF microscope, with a removable Bertrand lens as the only modification. Our technique has important applications for imaging axial vesicle dynamics and the mitochondrial energy state or detecting metabolically more active cancer cells.
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43
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Rieger B, Shalaeva DN, Söhnel AC, Kohl W, Duwe P, Mulkidjanian AY, Busch KB. Lifetime imaging of GFP at CoxVIIIa reports respiratory supercomplex assembly in live cells. Sci Rep 2017; 7:46055. [PMID: 28383048 PMCID: PMC5382582 DOI: 10.1038/srep46055] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 03/10/2017] [Indexed: 02/02/2023] Open
Abstract
The assembly of respiratory complexes into macromolecular supercomplexes is currently a hot topic, especially in the context of newly available structural details. However, most work to date has been done with purified detergent-solubilized material and in situ confirmation is absent. We here set out to enable the recording of respiratory supercomplex formation in living cells. Fluorescent sensor proteins were placed at specific positions at cytochrome c oxidase suspected to either be at the surface of a CI1CIII2CIV1 supercomplex or buried within this supercomplex. In contrast to other loci, sensors at subunits CoxVIIIa and CoxVIIc reported a dense protein environment, as detected by significantly shortened fluorescence lifetimes. According to 3D modelling CoxVIIIa and CoxVIIc are buried in the CI1CIII2CIV1 supercomplex. Suppression of supercomplex scaffold proteins HIGD2A and CoxVIIa2l was accompanied by an increase in the lifetime of the CoxVIIIa-sensor in line with release of CIV from supercomplexes. Strikingly, our data provide strong evidence for defined stable supercomplex configuration in situ.
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Affiliation(s)
- Bettina Rieger
- Institute of Molecular Cell Biology, School of Biology, University of Münster, D-48149 Münster, Germany.,Mitochondrial Dynamics Group, School of Biology, University of Osnabrueck, D-49076 Osnabrueck, Germany
| | - Daria N Shalaeva
- School of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany
| | - Anna-Carina Söhnel
- Institute of Molecular Cell Biology, School of Biology, University of Münster, D-48149 Münster, Germany.,Mitochondrial Dynamics Group, School of Biology, University of Osnabrueck, D-49076 Osnabrueck, Germany
| | - Wladislaw Kohl
- Mitochondrial Dynamics Group, School of Biology, University of Osnabrueck, D-49076 Osnabrueck, Germany
| | - Patrick Duwe
- Institute of Molecular Cell Biology, School of Biology, University of Münster, D-48149 Münster, Germany
| | - Armen Y Mulkidjanian
- School of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany.,School of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, 119992, Moscow, Russia.,A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119992, Moscow, Russia
| | - Karin B Busch
- Institute of Molecular Cell Biology, School of Biology, University of Münster, D-48149 Münster, Germany.,Mitochondrial Dynamics Group, School of Biology, University of Osnabrueck, D-49076 Osnabrueck, Germany
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44
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Kempe D, Cerminara M, Poblete S, Schöne A, Gabba M, Fitter J. Single-Molecule FRET Measurements in Additive-Enriched Aqueous Solutions. Anal Chem 2016; 89:694-702. [PMID: 27966879 DOI: 10.1021/acs.analchem.6b03147] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The addition of high amounts of chemical denaturants, salts, viscosity enhancers or macro-molecular crowding agents has an impact on the physical properties of buffer solutions. Among others, the (microscopic) viscosity, the refractive index, the dielectric constant, and the ionic strength can be affected. Here, we systematically evaluate the importance of solvent characteristics with respect to single-molecule FRET (smFRET) data. First, we present a confocal based method for the determination of fluorescence quantum yields to facilitate a fast characterization of smFRET-samples at sub-nM-concentrations. As a case study, we analyze smFRET data of structurally rigid, double-stranded DNA-oligonucleotides in aqueous buffer and in buffers with specific amounts of glycerol, guanidine hydrochloride (GdnHCl), and sodium chloride (NaCl) added. We show that the calculation of interdye distances, without taking into account solvent-induced spectral and photophysical changes of the labels, leads to deviations of up to 4 Å from the real interdye distances. Additionally, we demonstrate that electrostatic dye-dye repulsions are negligible for the interdye distance regime considered here (>50 Å). Finally, we use our approach to validate the further compaction of the already unfolded state of phosphoglycerate kinase (PGK) with decreasing denaturant concentrations, a mechanism known as coil-globule transition.
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Affiliation(s)
- Daryan Kempe
- AG Biophysik, I. Physikalisches Institut (IA), RWTH Aachen University , 52056 Aachen, Germany
| | | | | | | | | | - Jörg Fitter
- AG Biophysik, I. Physikalisches Institut (IA), RWTH Aachen University , 52056 Aachen, Germany
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45
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Chung PH, Tregidgo C, Suhling K. Determining a fluorophore’s transition dipole moment from fluorescence lifetime measurements in solvents of varying refractive index. Methods Appl Fluoresc 2016; 4:045001. [DOI: 10.1088/2050-6120/4/4/045001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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46
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Elsayad K, Werner S, Gallemí M, Kong J, Sánchez Guajardo ER, Zhang L, Jaillais Y, Greb T, Belkhadir Y. Mapping the subcellular mechanical properties of live cells in tissues with fluorescence emission-Brillouin imaging. Sci Signal 2016; 9:rs5. [PMID: 27382028 DOI: 10.1126/scisignal.aaf6326] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Extracellular matrices (ECMs) are central to the advent of multicellular life, and their mechanical properties are modulated by and impinge on intracellular signaling pathways that regulate vital cellular functions. High spatial-resolution mapping of mechanical properties in live cells is, however, extremely challenging. Thus, our understanding of how signaling pathways process physiological signals to generate appropriate mechanical responses is limited. We introduce fluorescence emission-Brillouin scattering imaging (FBi), a method for the parallel and all-optical measurements of mechanical properties and fluorescence at the submicrometer scale in living organisms. Using FBi, we showed that changes in cellular hydrostatic pressure and cytoplasm viscoelasticity modulate the mechanical signatures of plant ECMs. We further established that the measured "stiffness" of plant ECMs is symmetrically patterned in hypocotyl cells undergoing directional growth. Finally, application of this method to Arabidopsis thaliana with photoreceptor mutants revealed that red and far-red light signals are essential modulators of ECM viscoelasticity. By mapping the viscoelastic signatures of a complex ECM, we provide proof of principle for the organism-wide applicability of FBi for measuring the mechanical outputs of intracellular signaling pathways. As such, our work has implications for investigations of mechanosignaling pathways and developmental biology.
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Affiliation(s)
- Kareem Elsayad
- Advanced Microscopy Facility, Vienna Biocenter Core Facilities, A-1030 Vienna, Austria.
| | - Stephanie Werner
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, A-1030 Vienna, Austria
| | - Marçal Gallemí
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, A-1030 Vienna, Austria
| | - Jixiang Kong
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, A-1030 Vienna, Austria
| | | | - Lijuan Zhang
- Advanced Microscopy Facility, Vienna Biocenter Core Facilities, A-1030 Vienna, Austria
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, F-69342 Lyon, France
| | - Thomas Greb
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, A-1030 Vienna, Austria
| | - Youssef Belkhadir
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna Biocenter, A-1030 Vienna, Austria.
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47
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Lyndby NH, Kühl M, Wangpraseurt D. Heat generation and light scattering of green fluorescent protein-like pigments in coral tissue. Sci Rep 2016; 6:26599. [PMID: 27225857 PMCID: PMC4880895 DOI: 10.1038/srep26599] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/05/2016] [Indexed: 11/29/2022] Open
Abstract
Green fluorescent protein (GFP)-like pigments have been proposed to have beneficial effects on coral photobiology. Here, we investigated the relationships between green fluorescence, coral heating and tissue optics for the massive coral Dipsastraea sp. (previously Favia sp.). We used microsensors to measure tissue scalar irradiance and temperature along with hyperspectral imaging and combined imaging of variable chlorophyll fluorescence and green fluorescence. Green fluorescence correlated positively with coral heating and scalar irradiance enhancement at the tissue surface. Coral tissue heating saturated for maximal levels of green fluorescence. The action spectrum of coral surface heating revealed that heating was highest under red (peaking at 680 nm) irradiance. Scalar irradiance enhancement in coral tissue was highest when illuminated with blue light, but up to 62% (for the case of highest green fluorescence) of this photon enhancement was due to green fluorescence emission. We suggest that GFP-like pigments scatter the incident radiation, which enhances light absorption and heating of the coral. However, heating saturates, because intense light scattering reduces the vertical penetration depth through the tissue eventually leading to reduced light absorption at high fluorescent pigment density. We conclude that fluorescent pigments can have a central role in modulating coral light absorption and heating.
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Affiliation(s)
- Niclas H Lyndby
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark.,Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
| | - Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark.,Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
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48
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Probing of protein localization and shuttling in mitochondrial microcompartments by FLIM with sub-diffraction resolution. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1290-1299. [PMID: 27016377 DOI: 10.1016/j.bbabio.2016.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/17/2016] [Accepted: 03/18/2016] [Indexed: 12/31/2022]
Abstract
The cell is metabolically highly compartmentalized. Especially, mitochondria host many vital reactions in their different microcompartments. However, due to their small size, these microcompartments are not accessible by conventional microscopy. Here, we demonstrate that time-correlated single-photon counting (TCSPC) fluorescence lifetime-imaging microscopy (FLIM) classifies not only mitochondria, but different microcompartments inside mitochondria. Sensor proteins in the matrix had a different lifetime than probes at membrane proteins. Localization in the outer and inner mitochondrial membrane could be distinguished by significant differences in the lifetime. The method was sensitive enough to monitor shifts in protein location within mitochondrial microcompartments. Macromolecular crowding induced by changes in the protein content significantly affected the lifetime, while oxidizing conditions or physiological pH changes had only marginal effects. We suggest that FLIM is a versatile and completive method to monitor spatiotemporal events in mitochondria. The sensitivity in the time domain allows for gaining substantial information about sub-mitochondrial localization overcoming diffraction limitation. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Aubret A, Pillonnet A, Houel J, Dujardin C, Kulzer F. CdSe/ZnS quantum dots as sensors for the local refractive index. NANOSCALE 2016; 8:2317-2325. [PMID: 26750539 DOI: 10.1039/c5nr06998j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We explore the potential of CdSe/ZnS colloidal quantum dots (QDs) as probes for their immediate dielectric environment, based on the influence of the local refractive index on the fluorescence dynamics of these nanoemitters. We first compare ensembles of quantum dots in homogeneous solutions with single quantum dots dispersed on various dielectric substrates, which allows us to test the viability of a conceptual framework based on a hard-sphere region-of-influence and the Bruggeman effective-medium approach. We find that all our measurements can be integrated into a coherent description, provided that the conceptualized point-dipole emitter is positioned at a distance from the substrate that corresponds to the geometry of the QD. Three theoretical models for the evolution of the fluorescence decay rate as a function of the local refractive index are compared, showing that the classical Lorentz approach (virtual cavity) is the most appropriate for describing the data. Finally, we use the observed sensitivity of the QDs to their environment to estimate the detection limit, expressed as the minimum number of traceable streptavidin molecules, of a potential QD-nanosensor based on fluorescence lifetime.
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Affiliation(s)
- Antoine Aubret
- Institut Lumière-Matière, CNRS UMR5306, Université Lyon 1, Université de Lyon, 69622 Villeurbanne CEDEX, France.
| | - Anne Pillonnet
- Institut Lumière-Matière, CNRS UMR5306, Université Lyon 1, Université de Lyon, 69622 Villeurbanne CEDEX, France.
| | - Julien Houel
- Institut Lumière-Matière, CNRS UMR5306, Université Lyon 1, Université de Lyon, 69622 Villeurbanne CEDEX, France.
| | - Christophe Dujardin
- Institut Lumière-Matière, CNRS UMR5306, Université Lyon 1, Université de Lyon, 69622 Villeurbanne CEDEX, France.
| | - Florian Kulzer
- Institut Lumière-Matière, CNRS UMR5306, Université Lyon 1, Université de Lyon, 69622 Villeurbanne CEDEX, France.
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Nakabayashi T, Ohta N. Sensing of intracellular environments by fluorescence lifetime imaging of exogenous fluorophores. ANAL SCI 2016; 31:275-85. [PMID: 25864670 DOI: 10.2116/analsci.31.275] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Fluorescence lifetime imaging (FLIM) has been recognized as a powerful microscopy technique to examine environments in living systems. The fluorescence lifetime does not depend on the photobleaching and optical conditions, which allows us to obtain quantitative information on intracellular environments by analyzing the fluorescence lifetime. A variety of exogenous fluorophores have been applied in FLIM measurements to examine cellular processes. Information on the correlation between the fluorescence lifetime and the physiological parameters is essential to elucidate the cellular environments from the fluorescence lifetime measurements of exogenous fluorophores. In this review, exogenous fluorophores used for lifetime-based sensing are summarized, with the expectation that it becomes a basis for selecting the fluorophore used to investigate the intracellular environment with FLIM. Experimental results of the intracellular sensing of pH, metal ions, oxygen, viscosity, and other physiological parameters on the basis of the FLIM measurements are described along with a brief explanation of the mechanism of the change in the fluorescence lifetime.
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