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Abstract
There is a vast array of dyes currently available for measurement of cytosolic calcium. These encompass single and dual excitation and single and dual emission probes. The choice of particular probe depends on the experimental question and the type of equipment to be used. It is therefore extremely difficult to define a universal approach that will suit all potential investigators. Preparations under investigation are loaded with the selected organic indicator dye by incubation with ester derivatives, by micropipet injection or reverse permeabilization. Indicators can also be targeted to a range of intracellular organelles. Calibration of a fluorescent signal into Ca(2+) concentration is in theory relatively simple but the investigator needs to take great care in this process. This chapter describes the theory of these processes and some of the pitfalls users should be aware of. Precise experimental details can be found in the subsequent chapters of this volume.
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Affiliation(s)
- Alec W M Simpson
- Department of Cell and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
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2
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ANDERSSON-ENGELS S, ROKAHR I, CARLSSON J. Time- and wavelength-resolved spectroscopy in two-photon excited fluorescence microscopy. J Microsc 2011. [DOI: 10.1111/j.1365-2818.1994.tb03515.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Müller O, Tian Q, Zantl R, Kahl V, Lipp P, Kaestner L. A system for optical high resolution screening of electrical excitable cells. Cell Calcium 2010; 47:224-33. [DOI: 10.1016/j.ceca.2009.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 10/15/2009] [Accepted: 11/27/2009] [Indexed: 11/28/2022]
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4
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Cohen R, Torres A, Ma HT, Holowka D, Baird B. Ca2+ waves initiate antigen-stimulated Ca2+ responses in mast cells. THE JOURNAL OF IMMUNOLOGY 2009; 183:6478-88. [PMID: 19864608 DOI: 10.4049/jimmunol.0901615] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ca(2+) mobilization is central to many cellular processes, including stimulated exocytosis and cytokine production in mast cells. Using single cell stimulation by IgE-specific Ag and high-speed imaging of conventional or genetically encoded Ca(2+) sensors in rat basophilic leukemia and bone marrow-derived rat mast cells, we observe Ca(2+) waves that originate most frequently from the tips of extended cell protrusions, as well as Ca(2+) oscillations throughout the cell that usually follow the initiating Ca(2+) wave. In contrast, Ag conjugated to the tip of a micropipette stimulates local, repetitive Ca(2+) puffs at the region of cell contact. Initiating Ca(2+) waves are observed in most rat basophilic leukemia cells stimulated with soluble Ag and are sensitive to inhibitors of Ca(2+) release from endoplasmic reticulum stores and to extracellular Ca(2+), but they do not depend on store-operated Ca(2+) entry. Knockdown of transient receptor potential channel (TRPC)1 and TRPC3 channel proteins by short hairpin RNA reduces the sensitivity of these cells to Ag and shifts the wave initiation site from protrusions to the cell body. Our results reveal spatially encoded Ca(2+) signaling in response to immunoreceptor activation that utilizes TRPC channels to specify the initiation site of the Ca(2+) response.
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Affiliation(s)
- Roy Cohen
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
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5
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Abstract
Calcium signals mediate diverse cellular functions in immunological cells. Early studies with mast cells, then a preeminent model for studying Ca2+-dependent exocytosis, revealed several basic features of calcium signaling in non-electrically excitable cells. Subsequent studies in these and other cells further defined the basic processes such as inositol 1,4,5-trisphosphate-mediated release of Ca2+ from Ca2+ stores in the endoplasmic reticulum (ER); coupling of ER store depletion to influx of external Ca2+ through a calcium-release activated calcium (CRAC) channel now attributed to the interaction of the ER Ca2+ sensor, stromal interacting molecule-1 (STIM1), with a unique Ca2+-channel protein, Orai1/CRACM1, and subsequent uptake of excess Ca2+ into ER and mitochondria through ATP-dependent Ca2+ pumps. In addition, transient receptor potential channels and ion exchangers also contribute to the generation of calcium signals that may be global or have dynamic (e.g., waves and oscillations) and spatial resolution for specific functional readouts. This review discusses past and recent developments in this field of research, the pharmacologic agents that have assisted in these endeavors, and the mast cell as an exemplar for sorting out how calcium signals may regulate multiple outputs in a single cell.
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Affiliation(s)
- Hong-Tao Ma
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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6
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Cheezum MK, Walker WF, Guilford WH. Quantitative comparison of algorithms for tracking single fluorescent particles. Biophys J 2001; 81:2378-88. [PMID: 11566807 PMCID: PMC1301708 DOI: 10.1016/s0006-3495(01)75884-5] [Citation(s) in RCA: 469] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Single particle tracking has seen numerous applications in biophysics, ranging from the diffusion of proteins in cell membranes to the movement of molecular motors. A plethora of computer algorithms have been developed to monitor the sub-pixel displacement of fluorescent objects between successive video frames, and some have been claimed to have "nanometer" resolution. To date, there has been no rigorous comparison of these algorithms under realistic conditions. In this paper, we quantitatively compare specific implementations of four commonly used tracking algorithms: cross-correlation, sum-absolute difference, centroid, and direct Gaussian fit. Images of fluorescent objects ranging in size from point sources to 5 microm were computer generated with known sub-pixel displacements. Realistic noise was added and the above four algorithms were compared for accuracy and precision. We found that cross-correlation is the most accurate algorithm for large particles. However, for point sources, direct Gaussian fit to the intensity distribution is the superior algorithm in terms of both accuracy and precision, and is the most robust at low signal-to-noise. Most significantly, all four algorithms fail as the signal-to-noise ratio approaches 4. We judge direct Gaussian fit to be the best algorithm when tracking single fluorophores, where the signal-to-noise is frequently near 4.
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Affiliation(s)
- M K Cheezum
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA
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7
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Bacon KB. Calcium mobilization and phosphoinositide turnover as measure of chemokine receptor function in lymphocytes. Methods Enzymol 1997; 288:362-83. [PMID: 9357004 DOI: 10.1016/s0076-6879(97)88024-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- K B Bacon
- Department of Immunobiology, DNAX Research Institute, Palo Alto, California 94304-1104, USA
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8
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Mau SE, Witt MR, Saermark T, Vilhardt H. Substance P increases intracellular Ca2+ in individual rat pituitary lactotrophs, somatotrophs, and gonadotrophs. Mol Cell Endocrinol 1997; 126:193-201. [PMID: 9089657 DOI: 10.1016/s0303-7207(96)03988-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The present study has investigated transients in the intracellular calcium concentration [Ca2+]i in response to substance P (SP) in single pituitary cells. SP raised [Ca2+]i in three subtypes of pituitary cells: lactotrophs, somatotrophs, and gonadotrophs. In all three cell subtypes the [Ca2+]i response to SP was amplitude-modulated and a concentration of 100 nM was necessary to elicit well pronounced two phased [Ca2+]i transients. The first phase was associated with increased generation of inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) in all three cell types. In lactotrophs, the second phase, but not the first, was blunted by depletion of extracellular Ca2+ (Ca2+ free EGTA incubation buffer) and by addition of dopamine (1 microM). In somatotrophs, the second phase of the SP-induced [Ca2+]i response was inhibited by depletion of extracellular Ca2+ and by addition of somatostatin (100 nM), while the first phase was unaffected by this treatment. In gonadotrophs, the second phase, but not the first, was inhibited by the Ca2+ channel blocker methoxyverapamil and depletion of extracellular Ca2+. SP was compared with other agonists having an action on lactotrophs, somatotrophs or gonadotrophs. These experiments demonstrated that SP was a weaker agonist in terms of maximal [Ca2+]i response than thyrotropin-releasing hormone (TRH) (in lactotrophs), growth hormone-releasing hexapeptide (in somatotrophs) and GnRH (in gonadotrophs). On the basis of these results it is concluded that SP exerts direct Ca2+ mobilizing effects in single lactotrophs, somatotrophs, and gonadotrophs derived from male peripubertal rats. The first phase in SP-induced [Ca2+]i transients is likely to be brought about by inositol 1,4,5-trisphosphate-mediated Ca2+ release from internal stores while the second phase reflects an influx of calcium through voltage-gated calcium channels.
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Affiliation(s)
- S E Mau
- Department of Medical Physiology, Panum Institute, University of Copenhagen, Denmark.
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9
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Abstract
The performance characteristics of two sets of triple-band epifluorescence filters have been evaluated for use with digitally enhanced fluorescence microscopy. Use of such filters, at most, requires movement of the excitation filter, while the dichroic and emission filters remain fixed, allowing multi-wavelength imaging to be performed on standard microscopes. The dyes appropriate for use with these particular filters include Texas Red (TR), Bodipy (BD), FITC and Cascade Blue (CB), four fluorophores now commonly conjugated to both immunochemical probes and other proteins and lipids of biological interest. Good spectral separation existed for most experimental conditions allowing accurate localization of the different fluorophores during multi-wavelength imaging. Anomalous responses were observed during near-UV excitation at high concentration for some dyes. Scanning spectrofluorometry demonstrated that concentration-dependent spectral shifts occurred, resulting in large increases in near-UV absorbance. Despite the complexity of concentration and dye-interaction effects, quantitative measurements of dye concentration could be made, even in regions of multiple dye co-localization. Therefore, multi-band pass filters are an additional valuable approach for performing quantitative fluorescence microscopic imaging.
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Affiliation(s)
- R J Lowy
- Physiology Department, Armed Forces Radiobiology Research Institute, Bethesda, MD 20889-5603, USA
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10
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Electrophysiological Analysis of Ion Channel Function. Neurotoxicology 1995. [DOI: 10.1016/b978-012168055-8/50010-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Horikoshi Y, Furuno T, Teshima R, Sawada J, Nakanishi M. Thapsigargin-induced nuclear calcium signals in rat basophilic leukaemia cells. Biochem J 1994; 304 ( Pt 1):57-60. [PMID: 7998957 PMCID: PMC1137451 DOI: 10.1042/bj3040057] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
By a confocal fluorescence microscope with an argon-ion laser (488 nm) and a He-Cd laser (325 nm) we have studied thapsigargin-induced calcium signals in individual rat basophilic leukaemia (RBL-2H3) cells. In the presence or absence of external calcium ions, thapsigargin-induced calcium signals were transferred to the nucleus as well as to the cytoplasm of RBL-2H3 cells. The calcium signals were generally much stronger in the nucleus than in the cytoplasm. However, some of the RBL-2H3 cells had apparently reduced nuclear calcium signals. They had a basophil-like bilobed (multilobed) nucleus, although most RBL-2H3 cells had a mast-cell-like monolobed nucleus. In the cells with a bilobed nucleus, IgE-receptor-mediated calcium signals were neither transferred to the nucleus nor to the cytoplasm. The results gave a new insight into the understanding of the mechanism of the nuclear calcium signals in RBL-2H3 cells.
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Affiliation(s)
- Y Horikoshi
- Faculty of Pharmaceutical Sciences, Nagoya City University, Japan
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12
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Ghosh RN, Webb WW. Automated detection and tracking of individual and clustered cell surface low density lipoprotein receptor molecules. Biophys J 1994; 66:1301-18. [PMID: 8061186 PMCID: PMC1275851 DOI: 10.1016/s0006-3495(94)80939-7] [Citation(s) in RCA: 243] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have developed a technique to detect, recognize, and track each individual low density lipoprotein receptor (LDL-R) molecule and small receptor clusters on the surface of human skin fibroblasts. Molecular recognition and high precision (30 nm) simultaneous automatic tracking of all of the individual receptors in the cell surface population utilize quantitative time-lapse low light level digital video fluorescence microscopy analyzed by purpose-designed algorithms executed on an image processing work station. The LDL-Rs are labeled with the biologically active, fluorescent LDL derivative dil-LDL. Individual LDL-Rs and unresolved small clusters are identified by measuring the fluorescence power radiated by the sub-resolution fluorescent spots in the image; identification of single particles is ascertained by four independent techniques. An automated tracking routine was developed to track simultaneously, and without user intervention, a multitude of fluorescent particles through a sequence of hundreds of time-lapse image frames. The limitations on tracking precision were found to depend on the signal-to-noise ratio of the tracked particle image and mechanical drift of the microscope system. We describe the methods involved in (i) time-lapse acquisition of the low-light level images, (ii) simultaneous automated tracking of the fluorescent diffraction limited punctate images, (iii) localizing particles with high precision and limitations, and (iv) detecting and identifying single and clustered LDL-Rs. These methods are generally applicable and provide a powerful tool to visualize and measure dynamics and interactions of individual integral membrane proteins on living cell surfaces.
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Affiliation(s)
- R N Ghosh
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
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13
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Larkum ME, Warren DA, Bennett MR. Calcium concentration changes in the calyciform nerve terminal of the avian ciliary ganglion after tetanic stimulation. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1994; 46:175-88. [PMID: 8014371 DOI: 10.1016/0165-1838(94)90035-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A study has been made of the changes in calcium concentration in the calyciform nerve terminal ([Ca]c) and in the neurone soma ([Ca]s) of avian ciliary ganglion cells following tetanic stimulation of the nerve terminal. Dissociated ciliary neurones were loaded with the calcium indicator Fura-2 and digital imaging techniques used to determine the spatial and temporal distribution of calcium in the cells during post-tetanic potentiation (PTP) and long-term potentiation (LTP). Stimulation of the calyciform terminal with an extracellular electrode at 10 Hz for 2 s increased both [Ca]s and [Ca]s over 3-fold, with the [Ca] increasing for each impulse in the facilitatory train. The increase in [Ca]s could be prevented by allowing the terminal to degenerate in culture before stimulation. Stimulation of the calyciform terminal with a long tetanus of 30 Hz for 20 s gave an over 4-fold increase in both [Ca]c and [Ca]s by the end of the train. Analysis of the decline in [Ca]c after the train showed that it disappeared from the calyx along a double exponential time course with time constants of about 1 min and 50 min, respectively. These times are similar to those of PTP and LTP in the ganglia, and are almost independent of the extracellular calcium level. In order to determine whether the influx of calcium ions during a tetanus was through N-type calcium channels, these were blocked with adenosine (100 microM). Adenosine blocked the increase in both [Ca]s and [Ca]c that normally accompanies a tetanus. Thapsigargin (200 nM) did not affect [Ca]c or [Ca]s, but blocked transient increases in [Ca] caused by caffeine (10 mM) in both 3 mM and Ca2+ free bath solutions. These results are discussed in relation to the role of intracellular calcium in initiating LTP after a tetanus to the nerve terminals.
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Affiliation(s)
- M E Larkum
- Department of Physiology, University of Sydney, NSW, Australia
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14
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Lakowicz JR, Szmacinski H, Nowaczyk K, Lederer WJ, Kirby MS, Johnson ML. Fluorescence lifetime imaging of intracellular calcium in COS cells using Quin-2. Cell Calcium 1994; 15:7-27. [PMID: 8149407 PMCID: PMC6906927 DOI: 10.1016/0143-4160(94)90100-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We describe the first fluorescence lifetime images of cells. To demonstrate this new capability we measured intracellular images of Ca2+ in COS cells based on the Ca(2+)-dependent fluorescence lifetime of Quin-2. Apparent fluorescence lifetimes were measured by the phase-modulation method using a gain-modulated image intensifier and a slow-scan CCD camera. We describe methods to correct the images for photobleaching during acquisition of the data, and to correct for the position-dependent response of the image intensifier. The phase angle Quin-2 images were found to yield lower than expected Ca2+ concentrations, which appears to be the result of the formation of fluorescent photoproducts by Quin-2. Fluorescence lifetime imaging (FLIM) does not require wavelength-radiometric probes and appears to provide new opportunities for chemical imaging of cells.
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Affiliation(s)
- J R Lakowicz
- Department of Biological Chemistry, University of Maryland School of Medicine, Baltimore
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15
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Forsby A, Witt R, Walum E. Sesquiterpenoid unsaturated dialdehydes increase the concentration of intracellular free Ca2+ in human neuroblastoma SH-SY5Y cells. NATURAL TOXINS 1994; 2:89-95. [PMID: 8075898 DOI: 10.1002/nt.2620020207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of the three sesquiterpenoid unsaturated dialdehydes--polygodial, isovelleral, and epipolygodial--on intracellular free Ca2+ concentration, [Ca2+]i, was investigated in the human neuroblastoma cell line SH-SY5Y. [Ca2+]i was measured by the Fura-2 spectrophotofluorometric technique in multi-cell and single-cell experiments. Polygodial and isovelleral induced an increase in [Ca2+]i at low concentrations (0.1 and 0.5 micrograms/ml, respectively) but epipolygodial affected [Ca2+]i only at a high concentration (10 micrograms/ml). The results indicated that there was a relationship between the effect on [Ca2+]i and the pungency of the sesquiterpenes tested. Experiments in a Ca(2+)-free extracellular solution showed that Ca2+ was also released from intracellular calcium stores. Images from single-cell experiments indicated that polygodial induced fluctuations in the [Ca2+]i in some cells. The mechanism behind the sesquiterpene induced increase of the [Ca2+]i was not identified but a possible mobilization of inositol phosphates is considered.
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Affiliation(s)
- A Forsby
- Department of Animal Physiology, University of Lund, Sweden
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16
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Hartman RS, Lau K, Chou W, Coates TD. Development of a shape vector that identifies critical forms assumed by human polymorphonuclear neutrophils during chemotaxis. CYTOMETRY 1993; 14:832-9. [PMID: 8243213 DOI: 10.1002/cyto.990140717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Human polymorphonuclear neutrophils undergo characteristic shape changes that are critical to their ability to move and ingest their targets. We present here the construction of a simple shape vector, calculated from the coordinates of the cell perimeter, that can identify critical forms that a neutrophil assumes during the course of ameboid movement. The vector can be used to find neutrophils of a specific shape from the image analyzer data produced during a typical neutrophil tracking experiment.
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Affiliation(s)
- R S Hartman
- Division of Pediatric Hematology/Oncology, Childrens Hospital of Los Angeles, University of Southern California School of Medicine 90027
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17
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Szmacinski H, Gryczynski I, Lakowicz JR. Calcium-dependent fluorescence lifetimes of Indo-1 for one- and two-photon excitation of fluorescence. Photochem Photobiol 1993; 58:341-5. [PMID: 8234466 DOI: 10.1111/j.1751-1097.1993.tb09571.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We characterized the fluorescence intensity decays of Indo-1, which is commonly used as an emission wavelength-ratiometric calcium probe. The apparent lifetime of the long-wavelength side of the emission of Indo-1 is dependent on Ca2+. This long-wavelength emission displays the characteristics of an excited-state reaction, that is, a negative preexponential component in the multiexponential analysis. The emission spectra and lifetime of Indo-1 appear to be identical for one-photon and two-photon excitation at 351 and 702 mn, respectively, suggesting that the relative one- and two-photon cross sections are similar for the calcium-free and calcium-bound forms of Indo-1. Also, the two-photon cross section of Indo-1 is relatively high, about 4 x 10(-49) cm4 s/photon molecule at 690 nm for both the calcium-free and calcium-bound forms. Hence, Indo-1 can be used for calcium imaging based on one- or two-photon excitation, using either emission wavelength ratios or lifetime imaging methods.
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Affiliation(s)
- H Szmacinski
- Department of Biological Chemistry, University of Maryland at Baltimore 21201
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18
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Weinstock RS, Saville CM, Messina JL. Role of cytosolic calcium in regulation of cytoskeletal gene expression by insulin. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 264:E519-25. [PMID: 8476030 DOI: 10.1152/ajpendo.1993.264.4.e519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin and calcium ionophores rapidly stimulated transcription of the cytoskeletal beta- and gamma-actin genes in serum-deprived rat H4-II-E hepatoma cells. The calcium ionophore A23187 (1 microM) stimulated transcription of the beta-actin gene by 7.3-, 5.4-, and 2.6-fold and the gamma-actin gene by 5.9-, 5.6-, and 2.6-fold at 15, 30, and 60 min, respectively. Ionomycin (1 microM) similarly increased beta- and gamma-actin transcription. Insulin stimulated beta-actin transcription 11.4-fold and gamma-actin 8.4-fold at 30 min. alpha-Tubulin transcription was induced by both insulin and calcium ionophores but to a lesser degree. The effects of A23187 or ionomycin together with insulin for 30 min were no greater than those of insulin alone. Insulin alone, however, did not significantly increase measurable intracellular calcium concentrations in fura-2-loaded cells. When cytosolic calcium was chelated using quin2 acetoxymethyl ester, the ability of A23187 to increase beta- and gamma-actin transcription was completely abolished, whereas insulin's ability to stimulate actin transcription was only partially inhibited. This suggests that the regulation of gene transcription by insulin may include calcium-dependent pathways but strongly implies that calcium-independent pathways are also utilized.
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Affiliation(s)
- R S Weinstock
- Department of Veterans Affairs Medical Center, Syracuse, New York
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19
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Nakato K, Furuno T, Inagaki K, Teshima R, Terao T, Nakanishi M. Cytosolic and intranuclear calcium signals in rat basophilic leukemia cells as revealed by a confocal fluorescence microscope. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 209:745-9. [PMID: 1425678 DOI: 10.1111/j.1432-1033.1992.tb17343.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A confocal fluorescence microscope with an argon-ion laser (488 nm) and a He-Cd laser (325 nm) was used to study spatial heterogeneity of the calcium signals in rat basophilic leukemia 2H3 cloned cell line (RBL-2H3). After stimulation with antigen (2,4-dinitrophenol-conjugated bovine serum albumin), fluo-3-fluorescence intensities increased in individual RBL-2H3 cells with different lag times. Time-dependent profiles of the fluo-3-fluorescence intensities resembled closely the patterns of the sequential fluorescence-ratio images of fura-2, which were used to measure the intracellular free-calcium concentration ([Ca2+]i) in individual RBL-2H3 cells using a conventional fluorescence microscope. The present results obtained using the confocal fluorescence microscope showed spatial heterogeneities of fluo-3-fluorescence intensities, suggesting the existence of spatial heterogeneity of [Ca2+]i in RBL-2H3 cells. That is, the results showed that calcium signals first occurred transiently at pseudopodia in RBL-2H3 cells, then the signals transferred to the central parts of the cells. In addition, from the fluorescence images of co-loaded Hoechst 33342 (bisbenzimide H 33342, a DNA-specific probe) which were produced by excitation with a He-Cd laser, it was found that the fluorescence images of the nucleus were quite similar to those of the calcium signals mentioned above. This suggested that the receptor-mediated calcium signals were transferred not only to the cytoplasm but also to the nucleus.
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Affiliation(s)
- K Nakato
- Faculty of Pharmaceutical Sciences, Nagoya City University, Japan
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20
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Theler JM, Wollheim CB, Schlegel W. Rapid 'on-line' image processing as a tool in the evaluation of kinetic and morphological aspects of receptor-induced cell activation. JOURNAL OF RECEPTOR RESEARCH 1991; 11:627-39. [PMID: 1653352 DOI: 10.3109/10799899109066431] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Transmembrane signalling involves rapid and spatially well defined changes in cytosolic free Ca2+, [Ca2+]i. Specific technologies involving image processing permit the analysis of kinetic and morphological aspects of [Ca2+]i at the subcellular level with the fluorescent Ca2+ probe fura-2. Fluorescence excitation wavelengths (340 nm or 380 nm) are alternated in synchrony with the acquisition at video rate of images captured with an intensified CCD camera. Images are digitized, recursively filtered, divided, and displayed after calibration of the 'ratio' image into a numerical [Ca2+]i scale. The image processor IMAGINE (Synoptics Ltd., UK) permits these operations at video rate. This produces 'on-line' [Ca2+]i images in real time which are stored on video tapes for subsequent analysis. The present communication summarizes the rationale for the selection of our current technologies. A comparison with alternative solutions should highlight the particular advantages and drawbacks of our approach. The present text thus should serve as a help for investigators who try to assemble image processing tools for work in the receptor and cellular signalling field.
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Affiliation(s)
- J M Theler
- Dept. of Medicine, University of Geneva, Switzerland
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21
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Tsay TT, Inman R, Wray B, Herman B, Jacobson K. Characterization of low-light-level cameras for digitized video microscopy. J Microsc 1990; 160:141-59. [PMID: 2292794 DOI: 10.1111/j.1365-2818.1990.tb03054.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The use of low-light-level video cameras and solid-state image detectors in conjunction with image digitizers for optical microscopy is increasing dramatically as more people learn about such systems, and as they become more powerful, less expensive, and easier to use. However, there is currently little information available allowing comparison between cameras, or for determining camera suitability for a given experiment. In this paper, we describe a series of tests designed to characterize the performance of low-light-level cameras. The results of these tests should assist in the selection of appropriate cameras for given video microscopy applications.
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Affiliation(s)
- T T Tsay
- Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599
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Williams DA, Cody SH, Gehring CA, Parish RW, Harris PJ. Confocal imaging of ionised calcium in living plant cells. Cell Calcium 1990; 11:291-7. [PMID: 2113832 DOI: 10.1016/0143-4160(90)90006-g] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Laser-scanning confocal microscopy has been used in conjunction with Fluo-3, a highly fluorescent visible wavelength probe for Ca2+, to visualize Ca2(+)-dynamics in the function of living plant cells. This combination has overcome many of the problems that have limited the use of fluorescence imaging techniques in the study of the role of cations (Ca2+ and H+) in plant cell physiology and enables these processes to be studied in single cells within intact plant tissue preparations. Maize coleoptiles respond to application of ionophores and plant growth hormones with elevations in cytosolic Ca2+ that can be resolved with a high degree of spatial resolution and can be interpreted quantitatively.
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Affiliation(s)
- D A Williams
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
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