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Neikirk K, Lopez EG, Marshall AG, Alghanem A, Krystofiak E, Kula B, Smith N, Shao J, Katti P, Hinton A. Call to action to properly utilize electron microscopy to measure organelles to monitor disease. Eur J Cell Biol 2023; 102:151365. [PMID: 37864884 DOI: 10.1016/j.ejcb.2023.151365] [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: 08/16/2023] [Revised: 10/14/2023] [Accepted: 10/15/2023] [Indexed: 10/23/2023] Open
Abstract
This review provides an overview of the current methods for quantifying mitochondrial ultrastructure, including cristae morphology, mitochondrial contact sites, and recycling machinery and a guide to utilizing electron microscopy to effectively measure these organelles. Quantitative analysis of mitochondrial ultrastructure is essential for understanding mitochondrial biology and developing therapeutic strategies for mitochondrial-related diseases. Techniques such as transmission electron microscopy (TEM) and serial block face-scanning electron microscopy, as well as how they can be combined with other techniques including confocal microscopy, super-resolution microscopy, and correlative light and electron microscopy are discussed. Beyond their limitations and challenges, we also offer specific magnifications that may be best suited for TEM analysis of mitochondrial, endoplasmic reticulum, and recycling machinery. Finally, perspectives on future quantification methods are offered.
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Affiliation(s)
- Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Edgar-Garza Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Ahmad Alghanem
- King Abdullah International Medical Research Center (KAIMRC), Ali Al Arini, Ar Rimayah, Riyadh 11481, Saudi Arabia
| | - Evan Krystofiak
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Bartosz Kula
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester 14642, USA
| | - Nathan Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester 14642, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, USA
| | - Prasanna Katti
- National Heart, Lung and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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Caranfil A, Le Cunff Y, Kervrann C. BayesTICS: Local temporal image correlation spectroscopy and Bayesian simulation technique for sparse estimation of diffusion in fluorescence imaging. BIOLOGICAL IMAGING 2023; 3:e5. [PMID: 38487689 PMCID: PMC10936362 DOI: 10.1017/s2633903x23000041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 10/29/2022] [Accepted: 01/28/2023] [Indexed: 03/17/2024]
Abstract
The dynamics and fusion of vesicles during the last steps of exocytosis are not well established yet in cell biology. An open issue is the characterization of the diffusion process at the plasma membrane. Total internal reflection fluorescence microscopy (TIRFM) has been successfully used to analyze the coordination of proteins involved in this mechanism. It enables to capture dynamics of proteins with high frame rate and reasonable signal-to-noise values. Nevertheless, methodological approaches that can analyze and estimate diffusion in local small areas at the scale of a single diffusing spot within cells, are still lacking. To address this issue, we propose a novel correlation-based method for local diffusion estimation. As a starting point, we consider Fick's second law of diffusion that relates the diffusive flux to the gradient of the concentration. Then, we derive an explicit parametric model which is further fitted to time-correlation signals computed from regions of interest (ROI) containing individual spots. Our modeling and Bayesian estimation framework are well appropriate to represent isolated diffusion events and are robust to noise, ROI sizes, and localization of spots in ROIs. The performance of BayesTICS is shown on both synthetic and real TIRFM images depicting Transferrin Receptor proteins.
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Affiliation(s)
- Anca Caranfil
- SERPICO Project-Team, INRIA Rennes, UMR144 CNRS Institut Curie, PSL Research, Sorbonne Université, Campus universitaire de Beaulieu, Rennes, France
- CeDRE Team, GDR UMR6290-CNRS, Faculty of Medicine, University of Rennes 1, Rennes, France
| | - Yann Le Cunff
- CeDRE Team, GDR UMR6290-CNRS, Faculty of Medicine, University of Rennes 1, Rennes, France
- Dyliss Team, Univ Rennes, CNRS, Inria, IRISA, UMR 6074, Campus de Beaulieu, Rennes, France
| | - Charles Kervrann
- SERPICO Project-Team, INRIA Rennes, UMR144 CNRS Institut Curie, PSL Research, Sorbonne Université, Campus universitaire de Beaulieu, Rennes, France
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5 ns electric pulses induce Ca 2+-dependent exocytotic release of catecholamine from adrenal chromaffin cells. Bioelectrochemistry 2021; 140:107830. [PMID: 33965669 DOI: 10.1016/j.bioelechem.2021.107830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
Previously we reported that adrenal chromaffin cells exposed to a 5 ns, 5 MV/m pulse release the catecholamines norepinephrine (NE) and epinephrine (EPI) in a Ca2+-dependent manner. Here we determined that NE and EPI release increased with pulse number (one versus five and ten pulses at 1 Hz), established that release occurs by exocytosis, and characterized the exocytotic response in real-time. Evidence of an exocytotic mechanism was the appearance of dopamine-β-hydroxylase on the plasma membrane, and the demonstration by total internal reflection fluorescence microscopy studies that a train of five or ten pulses at 1 Hz triggered the release of the fluorescent dye acridine orange from secretory granules. Release events were Ca2+-dependent, longer-lived relative to those evoked by nicotinic receptor stimulation, and occurred with a delay of several seconds despite an immediate rise in Ca2+. In complementary studies, cells labeled with the plasma membrane fluorescent dye FM 1-43 and exposed to a train of ten pulses at 1 Hz underwent Ca2+-dependent increases in FM 1-43 fluorescence indicative of granule fusion with the plasma membrane due to exocytosis. These results demonstrate the effectiveness of ultrashort electric pulses for stimulating catecholamine release, signifying their promise as a novel electrostimulation modality for neurosecretion.
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Musovic S, Shrestha MM, Komai AM, Olofsson CS. Resistin is co-secreted with adiponectin in white mouse adipocytes. Biochem Biophys Res Commun 2020; 534:707-713. [PMID: 33261886 DOI: 10.1016/j.bbrc.2020.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 11/04/2020] [Indexed: 12/19/2022]
Abstract
In the current work we have investigated the cellular and molecular regulation of resistin secretion in cultured and primary mouse adipocytes. Resistin is an adipose tissue hormone proposed to contribute to metabolic disease. In rodents, resistin is secreted from white adipocytes whereas it is in humans synthesised and released from other cell types within white adipose tissue. The metabolic importance of resistin has been studied in both mouse and man, but the regulation of its release remains poorly investigated. Here we define that, in mouse adipocytes, resistin secretion is triggered by an intracellular elevation of cAMP and/or Ca2+. Resistin release is stimulated via activation of beta 3 adrenergic receptors (β3ARs) and the downstream signalling protein exchange protein activated by cAMP (Epac). The secretion of resistin is markedly abrogated in adipocytes isolated from obese and diabetic mice. Immunocytochemical staining demonstrates a significant overlap between signals for resistin and the adipocyte hormone adiponectin. Our data propose that resistin and adiponectin are contained within the same vesicles in mouse adipocytes and that the two hormones are co-secreted in response to the same exocytosis-triggering signals.
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Affiliation(s)
- Saliha Musovic
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Man Mohan Shrestha
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Ali M Komai
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden.
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5
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Colombo F, Norton EG, Cocucci E. Microscopy approaches to study extracellular vesicles. Biochim Biophys Acta Gen Subj 2020; 1865:129752. [PMID: 32991970 DOI: 10.1016/j.bbagen.2020.129752] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/05/2020] [Accepted: 08/18/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Extracellular vesicles (EVs) have drawn the attention of both biological researchers and clinical physicians due to their function in mediating cell-to-cell communication and relevance as potential diagnostic markers. Since their discovery, the small size and heterogeneity of EVs has posed a hindrance to their characterization as well as to the definition of their biological significance. SCOPE OF THE REVIEW Recent technological advances have considerably expanded the tools available for EV studies. In particular, the combination of novel microscope setups with high resolution imaging and the flexibility in EV labelling allows for the precise detection and characterization of the molecular composition of single EVs. Here we will review the microscopy techniques that have been applied to unravel the mechanism of EV-mediated intercellular communication and to study their molecular composition. MAJOR CONCLUSIONS Microscopy technologies have largely contributed to our understanding of molecular processes, including EV biology. As we discuss in this review, careful experimental planning is necessary to identify the most appropriate technique to use to answer a specific question. GENERAL SIGNIFICANCE The considerations regarding microscopy and experimental planning that are discussed here are applicable to the characterization of other small structures, including synthetic nanovectors and viruses.
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Affiliation(s)
- Federico Colombo
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Erienne G Norton
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Emanuele Cocucci
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA.
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Katoh K. Software-Based Three-Dimensional Deconvolution Microscopy of Cytoskeletal Proteins in Cultured Fibroblast Using Open-Source Software and Open Hardware. J Imaging 2019; 5:jimaging5120088. [PMID: 34460602 PMCID: PMC8321150 DOI: 10.3390/jimaging5120088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 11/16/2022] Open
Abstract
As conventional fluorescence microscopy and confocal laser scanning microscopy generally produce images with blurring at the upper and lower planes along the z-axis due to non-focal plane image information, the observation of biological images requires "deconvolution." Therefore, a microscope system's individual blur function (point spread function) is determined theoretically or by actual measurement of microbeads and processed mathematically to reduce noise and eliminate blurring as much as possible. Here the author describes the use of open-source software and open hardware design to build a deconvolution microscope at low cost, using readily available software and hardware. The advantage of this method is its cost-effectiveness and ability to construct a microscope system using commercially available optical components and open-source software. Although this system does not utilize expensive equipment, such as confocal and total internal reflection fluorescence microscopes, decent images can be obtained even without previous experience in electronics and optics.
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Affiliation(s)
- Kazuo Katoh
- Faculty of Health Sciences, Tsukuba University of Technology, Laboratory of Human Anatomy and Cell Biology, 4-12-7 Kasuga, Tsukuba-city, Ibaraki 305-8521, Japan
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7
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Zhang L, Liu XA, Gillis KD, Glass TE. A High-Affinity Fluorescent Sensor for Catecholamine: Application to Monitoring Norepinephrine Exocytosis. Angew Chem Int Ed Engl 2019; 58:7611-7614. [PMID: 30791180 DOI: 10.1002/anie.201810919] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/09/2019] [Indexed: 01/15/2023]
Abstract
A fluorescent sensor for catecholamines, NS510, is presented. The sensor is based on a quinolone fluorophore incorporating a boronic acid recognition element that gives it high affinity for catecholamines and a turn-on response to norepinephrine. The sensor results in punctate staining of norepinephrine-enriched chromaffin cells visualized using confocal microscopy indicating that it stains the norepinephrine in secretory vesicles. Amperometry in conjunction with total internal reflection fluorescence (TIRF) microscopy demonstrates that the sensor can be used to observe destaining of individual chromaffin granules upon exocytosis. NS510 is the highest affinity fluorescent norepinephrine sensor currently available and can be used for measuring catecholamines in live-cell assays.
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Affiliation(s)
- Le Zhang
- Department of Chemistry, University of Missouri, Columbia, Missouri, 65211, USA
| | - Xin A Liu
- Dalton Cardiovascular Research Center, Department of Bioengineering and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, 65211, USA
| | - Kevin D Gillis
- Dalton Cardiovascular Research Center, Department of Bioengineering and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, 65211, USA
| | - Timothy E Glass
- Department of Chemistry, University of Missouri, Columbia, Missouri, 65211, USA
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8
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Zhang L, Liu XA, Gillis KD, Glass TE. A High‐Affinity Fluorescent Sensor for Catecholamine: Application to Monitoring Norepinephrine Exocytosis. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201810919] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Le Zhang
- Department of ChemistryUniversity of Missouri Columbia Missouri 65211 USA
| | - Xin A. Liu
- Dalton Cardiovascular Research CenterDepartment of Bioengineering and Department of Medical Pharmacology and PhysiologyUniversity of Missouri Columbia Missouri 65211 USA
| | - Kevin D. Gillis
- Dalton Cardiovascular Research CenterDepartment of Bioengineering and Department of Medical Pharmacology and PhysiologyUniversity of Missouri Columbia Missouri 65211 USA
| | - Timothy E. Glass
- Department of ChemistryUniversity of Missouri Columbia Missouri 65211 USA
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Verboogen DRJ, Ter Beest M, Honigmann A, van den Bogaart G. Secretory vesicles of immune cells contain only a limited number of interleukin 6 molecules. FEBS Lett 2018; 592:1535-1544. [PMID: 29570778 PMCID: PMC5969217 DOI: 10.1002/1873-3468.13036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/12/2018] [Accepted: 03/13/2018] [Indexed: 01/06/2023]
Abstract
Immune cells communicate by releasing large quantities of cytokines. Although the mechanisms of cytokine secretion are increasingly understood, quantitative knowledge of the number of cytokines per vesicle is still lacking. Here, we measured with quantitative microscopy the release rate of vesicles potentially carrying interleukin‐6 (IL‐6) in human dendritic cells. By comparing this to the total secreted IL‐6, we estimate that secretory vesicles contain about 0.5–3 IL‐6 molecules, but with a large spread among cells/donors. Moreover, IL‐6 did not accumulate within most cells, indicating that synthesis and not trafficking is the bottleneck for IL‐6 production. IL‐6 accumulated in the Golgi apparatus only in ~ 10% of the cells. Understanding how immune cells produce cytokines is important for designing new immunomodulatory drugs.
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Affiliation(s)
- Daniëlle R J Verboogen
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alf Honigmann
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, the Netherlands
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Norris DM, Geddes TA, James DE, Fazakerley DJ, Burchfield JG. Glucose Transport: Methods for Interrogating GLUT4 Trafficking in Adipocytes. Methods Mol Biol 2018; 1713:193-215. [PMID: 29218527 DOI: 10.1007/978-1-4939-7507-5_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this chapter we detail methods for the systematic dissection of GLUT4 trafficking. The methods described have been optimized for cultured 3T3-L1 adipocytes, but can be readily adapted to other cell types.
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Affiliation(s)
- Dougall M Norris
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
- The Charles Perkins Centre, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Tom A Geddes
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
- The Charles Perkins Centre, The University of Sydney, Sydney, 2006, NSW, Australia
| | - David E James
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
- Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
- The Charles Perkins Centre, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Daniel J Fazakerley
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
- The Charles Perkins Centre, The University of Sydney, Sydney, 2006, NSW, Australia
| | - James G Burchfield
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia.
- The Charles Perkins Centre, The University of Sydney, Sydney, 2006, NSW, Australia.
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Basset A, Bouthemy P, Boulanger J, Waharte F, Salamero J, Kervrann C. An extended model of vesicle fusion at the plasma membrane to estimate protein lateral diffusion from TIRF microscopy images. BMC Bioinformatics 2017; 18:352. [PMID: 28738814 PMCID: PMC5525284 DOI: 10.1186/s12859-017-1765-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 07/14/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Characterizing membrane dynamics is a key issue to understand cell exchanges with the extra-cellular medium. Total internal reflection fluorescence microscopy (TIRFM) is well suited to focus on the late steps of exocytosis at the plasma membrane. However, it is still a challenging task to quantify (lateral) diffusion and estimate local dynamics of proteins. RESULTS A new model was introduced to represent the behavior of cargo transmembrane proteins during the vesicle fusion to the plasma membrane at the end of the exocytosis process. Two biophysical parameters, the diffusion coefficient and the release rate parameter, are automatically estimated from TIRFM image sequences, to account for both the lateral diffusion of molecules at the membrane and the continuous release of the proteins from the vesicle to the plasma membrane. Quantitative evaluation on 300 realistic computer-generated image sequences demonstrated the efficiency and accuracy of the method. The application of our method on 16 real TIRFM image sequences additionally revealed differences in the dynamic behavior of Transferrin Receptor (TfR) and Langerin proteins. CONCLUSION An automated method has been designed to simultaneously estimate the diffusion coefficient and the release rate for each individual vesicle fusion event at the plasma membrane in TIRFM image sequences. It can be exploited for further deciphering cell membrane dynamics.
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Affiliation(s)
- Antoine Basset
- Inria, Campus de Beaulieu, Rennes, 35042 France
- CNES, 18 avenue Edouard Belin, Toulouse, 31401 France
| | | | - Jérôme Boulanger
- Institut Curie, PSL Research University, CNRS UMR 144 and PICT-Cell and Tissue Imaging Facility, 12 rue Lhomond, Paris, 75005 France
- MRC Laboratory of Molecular Biology, University of Cambridge, Francis Crick Avenue, CBC Cambridge Biomedical Campus, Cambridge, CB2 0QH UK
| | - François Waharte
- Institut Curie, PSL Research University, CNRS UMR 144 and PICT-Cell and Tissue Imaging Facility, 12 rue Lhomond, Paris, 75005 France
| | - Jean Salamero
- Institut Curie, PSL Research University, CNRS UMR 144 and PICT-Cell and Tissue Imaging Facility, 12 rue Lhomond, Paris, 75005 France
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Je HJ, Kim MG, Kwon HJ. Bioluminescence Assays for Monitoring Chondrogenic Differentiation and Cartilage Regeneration. SENSORS 2017; 17:s17061306. [PMID: 28587284 PMCID: PMC5492100 DOI: 10.3390/s17061306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 05/24/2017] [Accepted: 06/02/2017] [Indexed: 02/06/2023]
Abstract
Since articular cartilage has a limited regeneration potential, for developing biological therapies for cartilage regeneration it is important to study the mechanisms underlying chondrogenesis of stem cells. Bioluminescence assays can visualize a wide range of biological phenomena such as gene expression, signaling, metabolism, development, cellular movements, and molecular interactions by using visible light and thus contribute substantially to elucidation of their biological functions. This article gives a concise review to introduce basic principles of bioluminescence assays and applications of the technology to visualize the processes of chondrogenesis and cartilage regeneration. Applications of bioluminescence assays have been highlighted in the methods of real-time monitoring of gene expression and intracellular levels of biomolecules and noninvasive cell tracking within animal models. This review suggests that bioluminescence assays can be applied towards a visual understanding of chondrogenesis and cartilage regeneration.
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Affiliation(s)
- Hyeon Jeong Je
- Department of Physical Therapy and Rehabilitation Science, College of Health Science, Eulji University, Gyeonggi 13135, Korea.
| | - Min Gu Kim
- Department of Physical Therapy and Rehabilitation Science, College of Health Science, Eulji University, Gyeonggi 13135, Korea.
| | - Hyuck Joon Kwon
- Department of Physical Therapy and Rehabilitation Science, College of Health Science, Eulji University, Gyeonggi 13135, Korea.
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Basset A, Boulanger J, Salamero J, Bouthemy P, Kervrann C. Adaptive Spot Detection With Optimal Scale Selection in Fluorescence Microscopy Images. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2015; 24:4512-4527. [PMID: 26353357 DOI: 10.1109/tip.2015.2450996] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Accurately detecting subcellular particles in fluorescence microscopy is of primary interest for further quantitative analysis such as counting, tracking, or classification. Our primary goal is to segment vesicles likely to share nearly the same size in fluorescence microscopy images. Our method termed adaptive thresholding of Laplacian of Gaussian (LoG) images with autoselected scale (ATLAS) automatically selects the optimal scale corresponding to the most frequent spot size in the image. Four criteria are proposed and compared to determine the optimal scale in a scale-space framework. Then, the segmentation stage amounts to thresholding the LoG of the intensity image. In contrast to other methods, the threshold is locally adapted given a probability of false alarm (PFA) specified by the user for the whole set of images to be processed. The local threshold is automatically derived from the PFA value and local image statistics estimated in a window whose size is not a critical parameter. We also propose a new data set for benchmarking, consisting of six collections of one hundred images each, which exploits backgrounds extracted from real microscopy images. We have carried out an extensive comparative evaluation on several data sets with ground-truth, which demonstrates that ATLAS outperforms existing methods. ATLAS does not need any fine parameter tuning and requires very low computation time. Convincing results are also reported on real total internal reflection fluorescence microscopy images.
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14
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Adenylyl cyclase localization to the uropod of aggregating Dictyostelium cells requires RacC. Biochem Biophys Res Commun 2015; 465:613-9. [PMID: 26315268 DOI: 10.1016/j.bbrc.2015.08.072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 08/17/2015] [Indexed: 11/21/2022]
Abstract
The localization of adenylyl cyclase A (ACA) to uropod of cells is required for the stream formation during Dictyostelium development. RacC is a Dictyostelium orthologue of Cdc42. We identified a streaming defect of racC(-) cells as they are clearly less polarized and form smaller and fragmented streams. ACA-YFP is mainly associated with intracellular vesicular structures, but not with the plasma membrane in racC(-) cells. racC(-) cells have a slightly higher number of vesicles than Ax3 cells, suggesting that the defect of ACA trafficking is not simply due to the lack of vesicle formation. While the ACA-YFP vesicles traveled with an average velocity of 9.1 μm/min in Ax3 cells, a slow and diffusional movement without direction with an average velocity of 4 μm/min was maintained in racC(-) cells. Images acquired by using total internal reflection fluorescence (TIRF) microscopy and fluorescence recovery after photobleaching (FRAP) analysis revealed that a significantly decreased number of ACA-YFP vesicles appeared near the cell membrane, indicating a defect in ACA-YFP vesicle trafficking. These results suggest an important role of RacC in the rapid and directional movements of ACA vesicles on microtubules to the plasma membrane, especially to the back of polarized cell.
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15
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Pillon NJ, Azizi PM, Li YE, Liu J, Wang C, Chan KL, Hopperton KE, Bazinet RP, Heit B, Bilan PJ, Lee WL, Klip A. Palmitate-induced inflammatory pathways in human adipose microvascular endothelial cells promote monocyte adhesion and impair insulin transcytosis. Am J Physiol Endocrinol Metab 2015; 309:E35-44. [PMID: 25944880 DOI: 10.1152/ajpendo.00611.2014] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 04/25/2015] [Indexed: 02/01/2023]
Abstract
Obesity is associated with inflammation and immune cell recruitment to adipose tissue, muscle and intima of atherosclerotic blood vessels. Obesity and hyperlipidemia are also associated with tissue insulin resistance and can compromise insulin delivery to muscle. The muscle/fat microvascular endothelium mediates insulin delivery and facilitates monocyte transmigration, yet its contribution to the consequences of hyperlipidemia is poorly understood. Using primary endothelial cells from human adipose tissue microvasculature (HAMEC), we investigated the effects of physiological levels of fatty acids on endothelial inflammation and function. Expression of cytokines and adhesion molecules was measured by RT-qPCR. Signaling pathways were evaluated by pharmacological manipulation and immunoblotting. Surface expression of adhesion molecules was determined by immunohistochemistry. THP1 monocyte interaction with HAMEC was measured by cell adhesion and migration across transwells. Insulin transcytosis was measured by total internal reflection fluorescence microscopy. Palmitate, but not palmitoleate, elevated the expression of IL-6, IL-8, TLR2 (Toll-like receptor 2), and intercellular adhesion molecule 1 (ICAM-1). HAMEC had markedly low fatty acid uptake and oxidation, and CD36 inhibition did not reverse the palmitate-induced expression of adhesion molecules, suggesting that inflammation did not arise from palmitate uptake/metabolism. Instead, inhibition of TLR4 to NF-κB signaling blunted palmitate-induced ICAM-1 expression. Importantly, palmitate-induced surface expression of ICAM-1 promoted monocyte binding and transmigration. Conversely, palmitate reduced insulin transcytosis, an effect reversed by TLR4 inhibition. In summary, palmitate activates inflammatory pathways in primary microvascular endothelial cells, impairing insulin transport and increasing monocyte transmigration. This behavior may contribute in vivo to reduced tissue insulin action and enhanced tissue infiltration by immune cells.
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Affiliation(s)
- Nicolas J Pillon
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paymon M Azizi
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada; Keenan Research Centre, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Yujin E Li
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jun Liu
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Changsen Wang
- Keenan Research Centre, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Kenny L Chan
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kathryn E Hopperton
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Bryan Heit
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada; and
| | - Philip J Bilan
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Warren L Lee
- Keenan Research Centre, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Amira Klip
- Cell Biology Program, the Hospital for Sick Children, Toronto, Ontario, Canada;
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16
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Rezatofighi SH, Gould S, Vo BT, Vo BN, Mele K, Hartley R. Multi-Target Tracking With Time-Varying Clutter Rate and Detection Profile: Application to Time-Lapse Cell Microscopy Sequences. IEEE TRANSACTIONS ON MEDICAL IMAGING 2015; 34:1336-1348. [PMID: 25594963 DOI: 10.1109/tmi.2015.2390647] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Quantitative analysis of the dynamics of tiny cellular and sub-cellular structures, known as particles, in time-lapse cell microscopy sequences requires the development of a reliable multi-target tracking method capable of tracking numerous similar targets in the presence of high levels of noise, high target density, complex motion patterns and intricate interactions. In this paper, we propose a framework for tracking these structures based on the random finite set Bayesian filtering framework. We focus on challenging biological applications where image characteristics such as noise and background intensity change during the acquisition process. Under these conditions, detection methods usually fail to detect all particles and are often followed by missed detections and many spurious measurements with unknown and time-varying rates. To deal with this, we propose a bootstrap filter composed of an estimator and a tracker. The estimator adaptively estimates the required meta parameters for the tracker such as clutter rate and the detection probability of the targets, while the tracker estimates the state of the targets. Our results show that the proposed approach can outperform state-of-the-art particle trackers on both synthetic and real data in this regime.
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17
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Bauereiss A, Welzel O, Jung J, Grosse-Holz S, Lelental N, Lewczuk P, Wenzel EM, Kornhuber J, Groemer TW. Surface Trafficking of APP and BACE in Live Cells. Traffic 2015; 16:655-75. [PMID: 25712587 PMCID: PMC6680167 DOI: 10.1111/tra.12270] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 02/06/2015] [Accepted: 02/09/2015] [Indexed: 12/22/2022]
Abstract
Amyloid‐β (Aβ)‐peptide, the major constituent of the plaques that develop during Alzheimer's disease, is generated via the cleavage of Aβ precursor protein (APP) by β‐site APP‐cleaving enzyme (BACE). Using live‐cell imaging of APP and BACE labeled with pH‐sensitive proteins, we could detect the release events of APP and BACE and their distinct kinetics. We provide kinetic evidence for the cleavage of APP by α‐secretase on the cellular surface after exocytosis. Furthermore, simultaneous dual‐color evanescent field illumination revealed that the two proteins are trafficked to the surface in separate compartments. Perturbing the membrane lipid composition resulted in a reduced frequency of exocytosis and affected BACE more strongly than APP. We propose that surface fusion frequency is a key factor regulating the aggregation of APP and BACE in the same membrane compartment and that this process can be modulated via pharmacological intervention.
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Affiliation(s)
- Anna Bauereiss
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Oliver Welzel
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Jasmin Jung
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Simon Grosse-Holz
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Natalia Lelental
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Piotr Lewczuk
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Eva M Wenzel
- Institute for Cancer Research, Department of Biochemistry, The Norwegian Radium Hospital, Montebello, N-0310, Oslo, Norway
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Teja W Groemer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
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18
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Schumacher K, Matz M, Brüning D, Baumann K, Rustenbeck I. Granule mobility, fusion frequency and insulin secretion are differentially affected by insulinotropic stimuli. Traffic 2015; 16:493-509. [PMID: 25615411 DOI: 10.1111/tra.12261] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 01/05/2015] [Accepted: 01/09/2015] [Indexed: 01/01/2023]
Abstract
The pre-exocytotic behavior of insulin granules was studied against the background of the entirety of submembrane granules in MIN6 cells, and the characteristics were compared with the macroscopic secretion pattern and the cytosolic Ca(2+) concentration of MIN6 pseudo-islets at 22°C, 32°C and 37°C. The mobility of granules labeled by insulin-EGFP and the fusion events were assessed by TIRF microscopy utilizing an observer-independent algorithm. In the z-dimension, 40 mm K(+) or 30 mm glucose increased the granule turnover. The effect of high K(+) was quickly reversible. The increase by glucose was more sustained and modified the efficacy of a subsequent K(+) stimulus. The effect size of glucose increased with physiological temperature whereas that of high K(+) did not. The mobility in the x/y-dimension and the fusion rates were little affected by the stimuli, in contrast to secretion. Fusion and secretion, however, had the same temperature dependence. Granules that appeared and fused within one image sequence had significantly larger caging diameters than pre-existent granules that underwent fusion. These in turn had a different mobility than residence-matched non-fusing granules. In conclusion, delivery to the membrane, tethering and fusion of granules are differently affected by insulinotropic stimuli. Fusion rates and secretion do not appear to be tightly coupled.
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Affiliation(s)
- Kirstin Schumacher
- Institute of Pharmacology and Toxicology, University of Braunschweig, Braunschweig, Germany
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19
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Liu L, Woolf A, Rodriguez AW, Capasso F. Absolute position total internal reflection microscopy with an optical tweezer. Proc Natl Acad Sci U S A 2014; 111:E5609-15. [PMID: 25512542 PMCID: PMC4284537 DOI: 10.1073/pnas.1422178112] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A noninvasive, in situ calibration method for total internal reflection microscopy (TIRM) based on optical tweezing is presented, which greatly expands the capabilities of this technique. We show that by making only simple modifications to the basic TIRM sensing setup and procedure, a probe particle's absolute position relative to a dielectric interface may be known with better than 10 nm precision out to a distance greater than 1 μm from the surface. This represents an approximate 10× improvement in error and 3× improvement in measurement range over conventional TIRM methods. The technique's advantage is in the direct measurement of the probe particle's scattering intensity vs. height profile in situ, rather than relying on assumptions, inexact system analogs, or detailed knowledge of system parameters for calibration. To demonstrate the improved versatility of the TIRM method in terms of tunability, precision, and range, we show our results for the hindered near-wall diffusion coefficient for a spherical dielectric particle.
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Affiliation(s)
- Lulu Liu
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138; and
| | - Alexander Woolf
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138; and
| | | | - Federico Capasso
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138; and
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20
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Boulanger J, Gueudry C, Münch D, Cinquin B, Paul-Gilloteaux P, Bardin S, Guérin C, Senger F, Blanchoin L, Salamero J. Fast high-resolution 3D total internal reflection fluorescence microscopy by incidence angle scanning and azimuthal averaging. Proc Natl Acad Sci U S A 2014; 111:17164-9. [PMID: 25404337 PMCID: PMC4260613 DOI: 10.1073/pnas.1414106111] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Total internal reflection fluorescence microscopy (TIRFM) is the method of choice to visualize a variety of cellular processes in particular events localized near the plasma membrane of live adherent cells. This imaging technique not relying on particular fluorescent probes provides a high sectioning capability. It is, however, restricted to a single plane. We present here a method based on a versatile design enabling fast multiwavelength azimuthal averaging and incidence angles scanning to computationally reconstruct 3D images sequences. We achieve unprecedented 50-nm axial resolution over a range of 800 nm above the coverslip. We apply this imaging modality to obtain structural and dynamical information about 3D actin architectures. We also temporally decipher distinct Rab11a-dependent exocytosis events in 3D at a rate of seven stacks per second.
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Affiliation(s)
| | - Charles Gueudry
- Plateforme Imagerie Cellulaire et Tissulaire-Infrastructure en Biologie Santé et Agronomie Institut Curie, 75005 Paris, France; Roper Scientific SAS, 91017 Evry, France; and
| | - Daniel Münch
- Plateforme Imagerie Cellulaire et Tissulaire-Infrastructure en Biologie Santé et Agronomie Institut Curie, 75005 Paris, France; Roper Scientific SAS, 91017 Evry, France; and
| | | | - Perrine Paul-Gilloteaux
- UMR144 CNRS/Institut Curie, 75005 Paris, France; Plateforme Imagerie Cellulaire et Tissulaire-Infrastructure en Biologie Santé et Agronomie Institut Curie, 75005 Paris, France
| | | | - Christophe Guérin
- Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Grenoble 38054, France
| | - Fabrice Senger
- Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Grenoble 38054, France
| | - Laurent Blanchoin
- Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Grenoble 38054, France
| | - Jean Salamero
- UMR144 CNRS/Institut Curie, 75005 Paris, France; Plateforme Imagerie Cellulaire et Tissulaire-Infrastructure en Biologie Santé et Agronomie Institut Curie, 75005 Paris, France;
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21
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Luo W, Xia T, Xu L, Chen YG, Fang X. Visualization of the post-Golgi vesicle-mediated transportation of TGF-β receptor II by quasi-TIRFM. JOURNAL OF BIOPHOTONICS 2014; 7:788-798. [PMID: 23606367 DOI: 10.1002/jbio.201300020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/25/2013] [Accepted: 03/25/2013] [Indexed: 06/02/2023]
Abstract
Transforming growth factor β receptor II (Tβ RII) is synthesized in the cytoplasm and then transported to the plasma membrane of cells to fulfil its signalling duty. Here, we applied live-cell fluorescence imaging techniques, in particular quasi-total internal reflection fluorescence microscopy, to imaging fluorescent protein-tagged Tβ RII and monitoring its secretion process. We observed punctuate-like Tβ RII-containing post-Golgi vesicles formed in MCF7 cells. Single-particle tracking showed that these vesicles travelled along the microtubules at an average speed of 0.51 μm/s. When stimulated by TGF-β ligand, these receptor-containing vesicles intended to move towards the plasma membrane. We also identified several factors that could inhibit the formation of such post-Golgi vesicles. Although the inhibitory mechanisms still remain unknown, the observed characteristics of Tβ RII-containing vesicles provide new information on intracellular Tβ RII transportation. It also renders Tβ RII a good model system for studying post-Golgi vesicle-trafficking and protein transportation.
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Affiliation(s)
- Wangxi Luo
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructures and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P.R. China
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22
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Brunstein M, Hérault K, Oheim M. Eliminating unwanted far-field excitation in objective-type TIRF. Part II. combined evanescent-wave excitation and supercritical-angle fluorescence detection improves optical sectioning. Biophys J 2014; 106:1044-56. [PMID: 24606929 PMCID: PMC4026779 DOI: 10.1016/j.bpj.2013.12.051] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 12/18/2013] [Accepted: 12/23/2013] [Indexed: 12/29/2022] Open
Abstract
Azimuthal beam scanning makes evanescent-wave (EW) excitation isotropic, thereby producing total internal reflection fluorescence (TIRF) images that are evenly lit. However, beam spinning does not fundamentally address the problem of propagating excitation light that is contaminating objective-type TIRF. Far-field excitation depends more on the specific objective than on cell scattering. As a consequence, the excitation impurities in objective-type TIRF are only weakly affected by changes of azimuthal or polar beam angle. These are the main results of the first part of this study (Eliminating unwanted far-field excitation in objective-type TIRF. Pt.1. Identifying sources of nonevanescent excitation light). This second part focuses on exactly where up beam in the illumination system stray light is generated that gives rise to nonevanescent components in TIRF. Using dark-field imaging of scattered excitation light we pinpoint the objective, intermediate lenses and, particularly, the beam scanner as the major sources of stray excitation. We study how adhesion-molecule coating and astrocytes or BON cells grown on the coverslip surface modify the dark-field signal. On flat and weakly scattering cells, most background comes from stray reflections produced far from the sample plane, in the beam scanner and the objective lens. On thick, optically dense cells roughly half of the scatter is generated by the sample itself. We finally show that combining objective-type EW excitation with supercritical-angle fluorescence (SAF) detection efficiently rejects the fluorescence originating from deeper sample regions. We demonstrate that SAF improves the surface selectivity of TIRF, even at shallow penetration depths. The coplanar microscopy scheme presented here merges the benefits of beam spinning EW excitation and SAF detection and provides the conditions for quantitative wide-field imaging of fluorophore dynamics at or near the plasma membrane.
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Affiliation(s)
- Maia Brunstein
- CNRS, UMR 8154, Paris, F-75006 France; INSERM, U603, Paris, F-75006 France; Laboratoire de Neurophysiologie et Nouvelles Microscopies, Université Paris Descartes, PRES Sorbonne Paris Cité, Paris, F-75006 France
| | - Karine Hérault
- CNRS, UMR 8154, Paris, F-75006 France; INSERM, U603, Paris, F-75006 France; Laboratoire de Neurophysiologie et Nouvelles Microscopies, Université Paris Descartes, PRES Sorbonne Paris Cité, Paris, F-75006 France
| | - Martin Oheim
- CNRS, UMR 8154, Paris, F-75006 France; INSERM, U603, Paris, F-75006 France; Laboratoire de Neurophysiologie et Nouvelles Microscopies, Université Paris Descartes, PRES Sorbonne Paris Cité, Paris, F-75006 France.
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23
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Matz M, Schumacher K, Hatlapatka K, Lorenz D, Baumann K, Rustenbeck I. Observer-independent quantification of insulin granule exocytosis and pre-exocytotic mobility by TIRF microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:206-218. [PMID: 24230985 DOI: 10.1017/s1431927613013767] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Total internal reflection fluorescence microscopy of fluorescently labeled secretory granules permits monitoring of exocytosis and the preceding granule behavior in one experiment. While observer-dependent evaluation may be sufficient to quantify exocytosis, most of the other information contained in the video files cannot be accessed this way. The present program performs observer-independent detection of exocytosis and tracking of the entire submembrane population of insulin granules. A precondition is the exact localization of the peak of the granule fluorescence. Tracking is based on the peak base radius, peak intensity, and the precrossing itineraries. Robustness of the tracking was shown by simulated tracks of original granule patterns. Mobility in the X-Y dimension is described by the caging diameter which in contrast to the widely used mean square displacement has an inherent time resolution. Observer-independent detection of exocytosis in MIN6 cells labeled with insulin-EGFP is based on the maximal decrease in fluorescence intensity and position of the centroid of the dissipating cloud of released material. Combining the quantification of KCl-induced insulin exocytosis with the analysis of prefusion mobility showed that during the last 3 s pre-exocytotic granules had a smaller caging diameter than control granules and that it increased significantly immediately before fusion.
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Affiliation(s)
- Magnus Matz
- Institute of Medicinal and Pharmaceutical Chemistry, University of Braunschweig, Braunschweig D38106, Germany
| | - Kirstin Schumacher
- Institute of Pharmacology and Toxicology, University of Braunschweig, Braunschweig D38106, Germany
| | - Kathrin Hatlapatka
- Institute of Pharmacology and Toxicology, University of Braunschweig, Braunschweig D38106, Germany
| | - Dirk Lorenz
- Institute of Analysis and Algebra, University of Braunschweig, Braunschweig D38106, Germany
| | - Knut Baumann
- Institute of Medicinal and Pharmaceutical Chemistry, University of Braunschweig, Braunschweig D38106, Germany
| | - Ingo Rustenbeck
- Institute of Pharmacology and Toxicology, University of Braunschweig, Braunschweig D38106, Germany
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24
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Hudecz D, Rocks L, Fitzpatrick LW, Herda LM, Dawson KA. Reproducibility in biological models of the blood-brain barrier. EUROPEAN JOURNAL OF NANOMEDICINE 2014. [DOI: 10.1515/ejnm-2014-0021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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25
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Klockow JL, Hettie KS, Glass TE. ExoSensor 517: a dual-analyte fluorescent chemosensor for visualizing neurotransmitter exocytosis. ACS Chem Neurosci 2013; 4:1334-8. [PMID: 23926946 DOI: 10.1021/cn400128s] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A dual-analyte fluorescent chemosensor (ExoSensor 517) for the direct visualization of neurotransmitters released upon exocytosis is presented. The sensor exploits the high concentration of neurotransmitters (e.g., glutamate, norepinephrine, and dopamine) and the pH gradient between the vesicle and synaptic cleft. The cooperative recognition elements require both binding and a change in environmental pH to afford a fluorescence response which makes ExoSensor 517 one of the first integrated molecular logic gates to be used for biological applications.
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Affiliation(s)
- Jessica L. Klockow
- Department of Chemistry, University of Missouri—Columbia, 601 South College
Avenue, Columbia, Missouri 65211, United States
| | - Kenneth S. Hettie
- Department of Chemistry, University of Missouri—Columbia, 601 South College
Avenue, Columbia, Missouri 65211, United States
| | - Timothy E. Glass
- Department of Chemistry, University of Missouri—Columbia, 601 South College
Avenue, Columbia, Missouri 65211, United States
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26
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Otterstrom J, van Oijen AM. Visualization of membrane fusion, one particle at a time. Biochemistry 2013; 52:1654-68. [PMID: 23421412 DOI: 10.1021/bi301573w] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Protein-mediated fusion between phospholipid bilayers is a fundamental and necessary mechanism for many cellular processes. The short-lived nature of the intermediate states visited during fusion makes it challenging to capture precise kinetic information using classical, ensemble-averaging biophysical techniques. Recently, a number of single-particle fluorescence microscopy-based assays that allow researchers to obtain highly quantitative data about the fusion process by observing individual fusion events in real time have been developed. These assays depend upon changes in the acquired fluorescence signal to provide a direct readout for transitions between the various fusion intermediates. The resulting data yield meaningful and detailed kinetic information about the transitory states en route to productive membrane fusion. In this review, we highlight recent in vitro and in vivo studies of membrane fusion at the single-particle level in the contexts of viral membrane fusion and SNARE-mediated synaptic vesicle fusion. These studies afford insight into mechanisms of coordination between fusion-mediating proteins as well as coordination of the overall fusion process with other cellular processes. The development of single-particle approaches to investigate membrane fusion and their successful application to a number of model systems have resulted in a new experimental paradigm and open up considerable opportunities to extend these methods to other biological processes that involve membrane fusion.
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Affiliation(s)
- Jason Otterstrom
- Harvard Biophysics Program, Harvard Medical School , 240 Longwood Avenue, Boston, Massachusetts 02115, United States
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27
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Application of the IMM-JPDA filter to multiple target tracking in total internal reflection fluorescence microscopy images. ACTA ACUST UNITED AC 2013. [PMID: 23285571 DOI: 10.1007/978-3-642-33415-3_44] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
We propose a multi-target tracking method using an Interacting Multiple Model Joint Probabilistic Data Association (IMM-JPDA) filter for tracking vesicles in total internal reflection fluorescence microscopy (TIRFM) sequences. We enhance the accuracy and reliability of the algorithm by tailoring an appropriate framework to this application. Evaluation of our algorithm is performed on both realistic synthetic data and real TIRFM data. Our results are compared against related methods and a commercial tracking software.
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28
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Burchfield JG, Lu J, Fazakerley DJ, Tan SX, Ng Y, Mele K, Buckley MJ, Han W, Hughes WE, James DE. Novel systems for dynamically assessing insulin action in live cells reveals heterogeneity in the insulin response. Traffic 2013; 14:259-73. [PMID: 23252720 DOI: 10.1111/tra.12035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/13/2012] [Accepted: 12/18/2012] [Indexed: 12/23/2022]
Abstract
Regulated GLUT4 trafficking is a key action of insulin. Quantitative stepwise analysis of this process provides a powerful tool for pinpointing regulatory nodes that contribute to insulin regulation and insulin resistance. We describe a novel GLUT4 construct and workflow for the streamlined dissection of GLUT4 trafficking; from simple high throughput screens to high resolution analyses of individual vesicles. We reveal single cell heterogeneity in insulin action highlighting the utility of this approach - each cell displayed a unique and highly reproducible insulin response, implying that each cell is hard-wired to produce a specific output in response to a given stimulus. These data highlight that the response of a cell population to insulin is underpinned by extensive heterogeneity at the single cell level. This heterogeneity is pre-programmed within each cell and is not the result of intracellular stochastic events.
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Affiliation(s)
- James G Burchfield
- Diabetes and Obesity Research Program, The Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
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29
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Oleinick A, Lemaître F, Collignon MG, Svir I, Amatore C. Vesicular release of neurotransmitters: converting amperometric measurements into size, dynamics and energetics of initial fusion pores. Faraday Discuss 2013; 164:33-55. [DOI: 10.1039/c3fd00028a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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30
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Lindberg E, Mizukami S, Ibata K, Fukano T, Miyawaki A, Kikuchi K. Development of cell-impermeable coelenterazine derivatives. Chem Sci 2013. [DOI: 10.1039/c3sc51985f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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31
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A multiple model probability hypothesis density tracker for time-lapse cell microscopy sequences. INFORMATION PROCESSING IN MEDICAL IMAGING : PROCEEDINGS OF THE ... CONFERENCE 2013. [PMID: 24683962 DOI: 10.1007/978-3-642-38868-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Quantitative analysis of the dynamics of tiny cellular and subcellular structures in time-lapse cell microscopy sequences requires the development of a reliable multi-target tracking method capable of tracking numerous similar targets in the presence of high levels of noise, high target density, maneuvering motion patterns and intricate interactions. The linear Gaussian jump Markov system probability hypothesis density (LGJMS-PHD) filter is a recent Bayesian tracking filter that is well-suited for this task. However, the existing recursion equations for this filter do not consider a state-dependent transition probability matrix. As required in many biological applications, we propose a new closed-form recursion that incorporates this assumption and introduce a general framework for particle tracking using the proposed filter. We apply our scheme to multi-target tracking in total internal reflection fluorescence microscopy (TIRFM) sequences and evaluate the performance of our filter against the existing LGJMS-PHD and IMM-JPDA filters.
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32
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Stamper IJ, Wang X. Mathematical modeling of insulin secretion and the role of glucose-dependent mobilization, docking, priming and fusion of insulin granules. J Theor Biol 2012; 318:210-25. [PMID: 23154190 DOI: 10.1016/j.jtbi.2012.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 10/28/2012] [Accepted: 11/02/2012] [Indexed: 01/08/2023]
Abstract
In this paper we develop a new mathematical model of glucose-induced insulin secretion from pancreatic islet β-cells, and we use this model to investigate the rate limiting factors. We assume that insulin granules reside in different pools inside each β-cell, and that all β-cells respond homogeneously to glucose with the same recruitment thresholds. Consistent with recent experimental observations, our model also accounts for the fusion of newcomer granules that are not pre-docked at the plasma membrane. In response to a single step increase in glucose concentration, our model reproduces the characteristic biphasic insulin release observed in multiple experimental systems, including perfused pancreata and isolated islets of rodent or human origin. From our model analysis we note that first-phase insulin secretion depends on rapid depletion of the primed, release-ready granule pools, while the second phase relies on granule mobilization from the reserve. Moreover, newcomers have the potential to contribute significantly to the second phase. When the glucose protocol consists of multiple changes in sequence (a so-called glucose staircase), our model predicts insulin spikes of increasing height, as has been seen experimentally. This increase stems from the glucose-dependent increase in the fusion rate of insulin granules at the plasma membrane of single β-cells. In contrast, previous mathematical models reproduced the staircase experiment by assuming heterogeneous β-cell activation. In light of experimental data indicating limited heterogeneous activation for β-cells within intact islets, our findings suggest that a graded, dose-dependent cell response to glucose may contribute to insulin secretion patterns observed in multiple experiments, and thus regulate in vivo insulin release. In addition, the strength of insulin granule mobilization, priming and fusion are critical limiting factors in determining the total amount of insulin release.
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Affiliation(s)
- I Johanna Stamper
- Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama, AL 35294, USA.
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Multiple roles for the actin cytoskeleton during regulated exocytosis. Cell Mol Life Sci 2012; 70:2099-121. [PMID: 22986507 DOI: 10.1007/s00018-012-1156-5] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/28/2012] [Accepted: 08/30/2012] [Indexed: 01/01/2023]
Abstract
Regulated exocytosis is the main mechanism utilized by specialized secretory cells to deliver molecules to the cell surface by virtue of membranous containers (i.e., secretory vesicles). The process involves a series of highly coordinated and sequential steps, which include the biogenesis of the vesicles, their delivery to the cell periphery, their fusion with the plasma membrane, and the release of their content into the extracellular space. Each of these steps is regulated by the actin cytoskeleton. In this review, we summarize the current knowledge regarding the involvement of actin and its associated molecules during each of the exocytic steps in vertebrates, and suggest that the overall role of the actin cytoskeleton during regulated exocytosis is linked to the architecture and the physiology of the secretory cells under examination. Specifically, in neurons, neuroendocrine, endocrine, and hematopoietic cells, which contain small secretory vesicles that undergo rapid exocytosis (on the order of milliseconds), the actin cytoskeleton plays a role in pre-fusion events, where it acts primarily as a functional barrier and facilitates docking. In exocrine and other secretory cells, which contain large secretory vesicles that undergo slow exocytosis (seconds to minutes), the actin cytoskeleton plays a role in post-fusion events, where it regulates the dynamics of the fusion pore, facilitates the integration of the vesicles into the plasma membrane, provides structural support, and promotes the expulsion of large cargo molecules.
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Le NCH, Dao DV, Yokokawa R, Nguyen TD, Wells JC, Sugiyama S. Highly-sensitive fluorescence detection and imaging with microfabricated total internal reflection (TIR)-based devices. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s12213-012-0043-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Yokokawa R, Kitazawa Y, Terao K, Okonogi A, Kanno I, Kotera H. A perfusable microfluidic device with on-chip total internal reflection fluorescence microscopy (TIRFM) for in situ and real-time monitoring of live cells. Biomed Microdevices 2012; 14:791-7. [DOI: 10.1007/s10544-012-9656-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Masedunskas A, Porat-Shliom N, Weigert R. Regulated exocytosis: novel insights from intravital microscopy. Traffic 2012; 13:627-34. [PMID: 22243493 DOI: 10.1111/j.1600-0854.2012.01328.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/11/2012] [Accepted: 01/13/2012] [Indexed: 12/20/2022]
Abstract
Regulated exocytosis is a fundamental process that every secretory cell uses to deliver molecules to the cell surface and the extracellular space by virtue of membranous carriers. This process has been extensively studied using various approaches such as biochemistry, electrophysiology and electron microscopy. However, recent developments in time-lapse light microscopy have made possible imaging individual exocytic events, hence, advancing our understanding of this process at a molecular level. In this review, we focus on intravital microscopy (IVM), a light microscopy-based approach that enables imaging subcellular structures in live animals, and discuss its recent application to study regulated exocytosis. IVM has revealed differences in regulation and modality of regulated exocytosis between in vitro and in vivo model systems, unraveled novel aspects of this process that can be appreciated only in in vivo settings and provided valuable and novel information on its molecular machinery. In conclusion, we make the case for IVM being a mature technique that can be used to investigate the molecular machinery of several intracellular events under physiological conditions.
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Affiliation(s)
- Andrius Masedunskas
- Intracellular Membrane Trafficking Unit, Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Dr. 303A, Bethesda, MD 20892-4340, USA
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Using Total Internal Reflection Fluorescence Microscopy (TIRFM) to Visualise Insulin Action. VISUALIZATION TECHNIQUES 2012. [DOI: 10.1007/978-1-61779-897-9_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Visualizing the endocytic and exocytic processes of wheat germ agglutinin by quantum dot-based single-particle tracking. Biomaterials 2011; 32:7616-24. [DOI: 10.1016/j.biomaterials.2011.06.046] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 06/20/2011] [Indexed: 11/18/2022]
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Mi HW, Lee MC, Chiang YC, Chow LP, Lin CP. Single-Molecule Imaging of Bmp4 Dimerization on Human Periodontal Ligament Cells. J Dent Res 2011; 90:1318-24. [DOI: 10.1177/0022034511418340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We expressed bone morphogenetic protein 4 (BMP4) fused with enhanced green fluorescent protein (BMP4-EGFP) in the secretory pathways of producer cells. Fluorescent EGFP was acquired only after we interrupted the transport of BMP4-EGFP by culturing cells at a lower temperature (20°C), and the dynamics of BMP4-EGFP could be monitored by single-molecule microscopy. Western blotting analysis confirmed that exposure to low temperature helped the integrated formation of BMP4-EGFP fusion proteins. In this study, for the first time, we could image the fluorescently labeled BMP4 molecules localized on the plasma membrane of living hPDL cells. The one-step photobleaching with EGFP and the “blinking” behavior of quantum dots suggest that the fluorescent spots represent the events of single BMP4 molecules. Single-molecule tracking showed that the BMP receptors (BMPR) dimerize after BMP4 stimulation, or that a complex of one BMP4 molecule and a pre-formed BMPR dimer develops first, followed by the binding of the second BMP4 molecule. Furthermore, BMP4-EGFP enhanced the osteogenic differentiation of hPDL cells via signal transduction involving BMP receptors. This single-molecule imaging technique might be a valuable tool for the future development of BMP4 gene therapy and regenerative medicine mediated by hPDLs. Abbreviations: BMP4, bone morphogenetic protein 4; BMPR, BMP receptor; EGFP, enhanced green fluorescent protein; hPDL cells, human periodontal ligament cells; QDs, quantum dots; TIRFM, total internal reflection fluorescence microscopy; 293 cells, human embryonic kidney cells; oDM, osteogenic differentiation medium; HcoI, type I collagen; ALP, alkaline phosphatase; BSP, bone sialoprotein; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.
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Affiliation(s)
- H.-W. Mi
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University and National Taiwan University Hospital, No.1, Changde St., Jhongjheng District, Taipei 100, Taiwan, ROC
| | - M.-C. Lee
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Y.-C. Chiang
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University and National Taiwan University Hospital, No.1, Changde St., Jhongjheng District, Taipei 100, Taiwan, ROC
| | - L.-P. Chow
- Graduate Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - C.-P. Lin
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University and National Taiwan University Hospital, No.1, Changde St., Jhongjheng District, Taipei 100, Taiwan, ROC
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Meunier A, Jouannot O, Fulcrand R, Fanget I, Bretou M, Karatekin E, Arbault S, Guille M, Darchen F, Lemaître F, Amatore C. Coupling amperometry and total internal reflection fluorescence microscopy at ITO surfaces for monitoring exocytosis of single vesicles. Angew Chem Int Ed Engl 2011; 50:5081-4. [PMID: 21523868 DOI: 10.1002/anie.201101148] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Indexed: 11/11/2022]
Affiliation(s)
- Anne Meunier
- Département de Chimie, Ecole Normale Supérieure UMR 8640 (CNRS-ENS-UPMC Univ Paris 06), 24 rue Lhomond, 75005 Paris, France
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Meunier A, Jouannot O, Fulcrand R, Fanget I, Bretou M, Karatekin E, Arbault S, Guille M, Darchen F, Lemaître F, Amatore C. Coupling Amperometry and Total Internal Reflection Fluorescence Microscopy at ITO Surfaces for Monitoring Exocytosis of Single Vesicles. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101148] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Kudlinski A, Barviau B, Leray A, Spriet C, Héliot L, Mussot A. Control of pulse-to-pulse fluctuations in visible supercontinuum. OPTICS EXPRESS 2010; 18:27445-27454. [PMID: 21197020 DOI: 10.1364/oe.18.027445] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Long-pulse supercontinuum sources are initiated by modulation instability and consequently suffer from stochastic shot-to-shot variations of their spectral power density. In this paper, we provide a measurement of pulse-to-pulse fluctuations over the whole supercontinuum spectrum, and we show that their spectral dependence follows the group index curve of the fiber. Then, we demonstrate a significant reduction of supercontinuum pulse-to-pulse fluctuations in the visible by using a photonic crystal fiber with longitudinally tailored guidance properties. We finally show numerically that this new source would allow a significant improvement of the signal-to-noise ratio in fluorescence microscopy.
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Affiliation(s)
- A Kudlinski
- Université Lille 1, IRCICA, FR CNRS 3024, Laboratoire PhLAM, UMR CNRS 8523, Villeneuve d'Ascq, France.
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Stenkula KG, Lizunov VA, Cushman SW, Zimmerberg J. Insulin controls the spatial distribution of GLUT4 on the cell surface through regulation of its postfusion dispersal. Cell Metab 2010; 12:250-9. [PMID: 20816091 PMCID: PMC3427691 DOI: 10.1016/j.cmet.2010.08.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 05/19/2010] [Accepted: 06/07/2010] [Indexed: 01/06/2023]
Abstract
While the glucose transporter-4 (GLUT4) is fundamental to insulin-regulated glucose metabolism, its dynamic spatial organization in the plasma membrane (PM) is unclear. Here, using multicolor TIRF microscopy in transfected adipose cells, we demonstrate that insulin regulates not only the exocytosis of GLUT4 storage vesicles but also PM distribution of GLUT4 itself. In the basal state, domains (clusters) of GLUT4 molecules in PM are created by an exocytosis that retains GLUT4 at the fusion site. Surprisingly, when insulin induces a burst of GLUT4 exocytosis, it does not merely accelerate this basal exocytosis but rather stimulates approximately 60-fold another mode of exocytosis that disperses GLUT4 into PM. In contradistinction, internalization of most GLUT4, regardless of insulin, occurs from pre-existing clusters via the subsequent recruitment of clathrin. The data fit a new kinetic model that features multifunctional clusters as intermediates of exocytosis and endocytosis.
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Affiliation(s)
- Karin G Stenkula
- Experimental Diabetes, Metabolism, and Nutrition Section, Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Lopez JA, Burchfield JG, Blair DH, Mele K, Ng Y, Vallotton P, James DE, Hughes WE. Identification of a distal GLUT4 trafficking event controlled by actin polymerization. Mol Biol Cell 2009; 20:3918-29. [PMID: 19605560 DOI: 10.1091/mbc.e09-03-0187] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The insulin-stimulated trafficking of GLUT4 to the plasma membrane in muscle and fat tissue constitutes a central process in blood glucose homeostasis. The tethering, docking, and fusion of GLUT4 vesicles with the plasma membrane (PM) represent the most distal steps in this pathway and have been recently shown to be key targets of insulin action. However, it remains unclear how insulin influences these processes to promote the insertion of the glucose transporter into the PM. In this study we have identified a previously uncharacterized role for cortical actin in the distal trafficking of GLUT4. Using high-frequency total internal reflection fluorescence microscopy (TIRFM) imaging, we show that insulin increases actin polymerization near the PM and that disruption of this process inhibited GLUT4 exocytosis. Using TIRFM in combination with probes that could distinguish between vesicle transport and fusion, we found that defective actin remodeling was accompanied by normal insulin-regulated accumulation of GLUT4 vesicles close to the PM, but the final exocytotic fusion step was impaired. These data clearly resolve multiple steps of the final stages of GLUT4 trafficking, demonstrating a crucial role for actin in the final stage of this process.
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Affiliation(s)
- Jamie A Lopez
- Diabetes and Obesity Research Program, The Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
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