Mechanism of collagen activation in human platelets.
AuthorsRoberts DE, McNicol A, Bose R
JournalJ Biol Chem
PubMed ID14981087
The mechanism of collagen-induced human platelet activation was examined using Ca2+, Na+, and the pH-sensitive fluorescent dyes calcium green/fura red, sodium-binding benzofuran isophthalate, and 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Administration of a moderate dose of collagen (10 microg/ml) to human platelets resulted in an increase in [Ca2+](i) and platelet aggregation. The majority of this ... More
Cluster formation of inositol 1,4,5-trisphosphate receptor requires its transition to open state.
AuthorsTateishi Y, Hattori M, Nakayama T, Iwai M, Bannai H, Nakamura T, Michikawa T, Inoue T, Mikoshiba K
JournalJ Biol Chem
PubMed ID15583010
'The inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) Ca(2+) channel plays pivotal roles in many aspects of physiological and pathological events. It was previously reported that IP(3)R forms clusters on the endoplasmic reticulum when cytosolic Ca(2+) concentration ([Ca(2+)](C)) is elevated. However, the molecular mechanism of IP(3)R clustering remains largely unknown, and thus ... More
Triad formation: organization and function of the sarcoplasmic reticulum calcium release channel and triadin in normal and dysgenic muscle in vitro.
AuthorsFlucher BE, Andrews SB, Fleischer S, Marks AR, Caswell A, Powell JA
JournalJ Cell Biol
PubMed ID8245124
'Excitation-contraction (E-C) coupling is thought to involve close interactions between the calcium release channel (ryanodine receptor; RyR) of the sarcoplasmic reticulum (SR) and the dihydropyridine receptor (DHPR) alpha 1 subunit in the T-tubule membrane. Triadin, a 95-kD protein isolated from heavy SR, binds both the RyR and DHPR and may ... More
Real time fluorescence imaging of PLC gamma translocation and its interaction with the epidermal growth factor receptor.
AuthorsMatsuda M, Paterson HF, Rodriguez R, Fensome AC, Ellis MV, Swann K, Katan M
JournalJ Cell Biol
PubMed ID11331309
'The translocation of fluorescently tagged PLC gamma and requirements for this process in cells stimulated with EGF were analyzed using real time fluorescence microscopy applied for the first time to monitor growth factor receptor--effector interactions. The translocation of PLC gamma to the plasma membrane required the functional Src homology 2 ... More
Vav1 and Ly-GDI two regulators of Rho GTPases, function cooperatively as signal transducers in T cell antigen receptor-induced pathways.
AuthorsGroysman M, Hornstein I, Alcover A, Katzav S
JournalJ Biol Chem
PubMed ID12386169
'The Rho family GTPases are pivotal for T cell signaling; however, the regulation of these proteins is not fully known. One well studied regulator of Rho GTPases is Vav1; a hematopoietic cell-specific guanine nucleotide exchange factor critical for signaling in T cells, including stimulation of the nuclear factor of activated ... More
Detection of a trigger zone of bradykinin-induced fast calcium waves in PC12 neurites.
AuthorsReber BF, Schindelholz B
JournalPflugers Arch
PubMed ID8772141
'Bradykinin and caffeine were used as two different agonists to study inositol 1,4,5-trisphosphate (IP3)-sensitive and caffeine/ryanodine-sensitive intracellular Ca2+ release in the outgrowing neurites of nerve-growth-factor (NGF)-treated rat phaeochromocytoma cells (PC12). Changes in neuritic intracellular free Ca2+ ([Ca2+]i) in single cells were measured after loading with a 1:1 mixture of the ... More
AM-loading of fluorescent Ca2+ indicators into intact single fibers of frog muscle.
AuthorsZhao M, Hollingworth S, Baylor SM
JournalBiophys J
PubMed ID9168048
'The AM loading of a number of different fluorescent Ca2+ indicators was compared in intact single fibers of frog muscle. Among the 13 indicators studied, loading rates (the average increase in the fiber concentration of indicator per first 60 min of loading) varied approximately 100-fold, from approximately 3 microM/h to ... More
Apoptogenic ganglioside GD3 directly induces the mitochondrial permeability transition.
AuthorsKristal BS, Brown AM
JournalJ Biol Chem
PubMed ID10438487
'Early events in apoptotic cascades initiated by ceramides or by activation of the surface receptor CD95 (Fas/APO-1) include the formation of ganglioside GD3. GD3 appears to be both necessary and sufficient to propagate this lipid-mediated apoptotic pathway. Later events common to many apoptotic pathways include induction of the mitochondrial permeability ... More
Mapping the sensitivity of T cells with an optical trap: polarity and minimal number of receptors for Ca(2+) signaling.
AuthorsWei X, Tromberg BJ, Cahalan MD
JournalProc Natl Acad Sci U S A
PubMed ID10411899
'Contact with antigen-presenting cells (APCs) initiates an activation cascade within T lymphocytes, including a rise in cytosolic calcium, lymphokine production, and cell division. Although T cell-APC physical contact is required for an immune response, little is known about the patterns of cellular interactions and their relation to activation. Calcium imaging ... More
Correlation of NADH and Ca2+ signals in mouse pancreatic acinar cells.
AuthorsVoronina S, Sukhomlin T, Johnson PR, Erdemli G, Petersen OH, Tepikin A
JournalJ Physiol
PubMed ID11850500
'Relationships between calcium signals and NADH responses were investigated in pancreatic acinar cells stimulated with calcium-releasing secretagogues. Cytosolic calcium signals were studied using Fura Red or calcium-sensitive Cl(-) current. Mitochondrial calcium was measured using Rhod-2. The highest levels of NADH autofluorescence were found around the secretory granule region. Stimulation of ... More
Use of fluorescent Ca2+ dyes with green fluorescent protein and its variants: problems and solutions.
AuthorsBolsover S, Ibrahim O, O'luanaigh N, Williams H, Cockcroft S
JournalBiochem J
PubMed ID11368760
'We have studied the degree to which fluorescent Ca(2+) indicator dyes, and green fluorescent protein and its variants, can be used together. We find that the most commonly used fluorescent protein, enhanced green fluorescent protein (EGFP), seriously contaminates fura 2 signals. We suggest two alternative combinations for which there is ... More
Phosphatidylinositol 3-kinase-dependent extracellular calcium influx is essential for CX(3)CR1-mediated activation of the mitogen-activated protein kinase cascade.
'Fractalkine, the first member of the CX(3)C chemokine family, induces leukocyte chemotaxis through activation of its high affinity receptor, CX(3)CR1. Like other chemokine receptors, CX(3)CR1 is coupled to a pertussis toxin-sensitive heterotrimeric G(i) protein, which is necessary for rapid rise in the concentration of intracellular calcium. Using a Chinese hamster ... More
AuthorsMaruyama Y, Inooka G, Li YX, Miyashita Y, Kasai H
JournalEMBO J
PubMed ID8344243
'We investigated how agonist-induced patterned rises in cytosolic Ca2+ concentration ([Ca2+]i) regulate exocytotic secretion in the rat pancreatic acinar cell. The distribution of [Ca2+]i was visualized with a confocal microscope, which revealed that a Ca2+ ionophore, A23187, induced slow and homogeneous [Ca2+]i rises, while acetylcholine (ACh) always triggered primary Ca2+ ... More
Glutamate triggers rapid glucose transport stimulation in astrocytes as evidenced by real-time confocal microscopy.
AuthorsLoaiza A, Porras OH, Barros LF
JournalJ Neurosci
PubMed ID12917367
'Glutamate stimulates glycolysis in astrocytes, a phenomenon that couples astrocytic metabolism with neuronal activity. However, it is not known whether glutamate also affects glucose transporter-1 (GLUT1), the transporter responsible for glucose entry into astrocytes. To address this question, two different real-time single-cell hexose uptake assays were applied to cultured hippocampal ... More
Multidrug transporter activity in lymphocytes.
AuthorsElliott JI, Raguz S, Higgins CF,
JournalBr J Pharmacol
PubMed ID15492020
'Multidrug transporters play a dual role in haematopoietic cells, mediating the efflux of xenobiotics and regulating cell migration. For several reasons including the lack of specific antibodies, reports of multidrug transporter distribution on lymphocytes conflict. Murine B cells have been reported to completely lack transporter activity. Through analysis of parental ... More
Calcium homeostasis of isolated single cortical fibers of rat lens.
AuthorsSrivastava SK, Wang LF, Ansari NH, Bhatnagar A
JournalInvest Ophthalmol Vis Sci
PubMed ID9344353
'PURPOSE: To investigate the calcium homeostasis in single fiber cells isolated from rat ocular lens cortex and to quantify the changes in the concentration of free intracellular calcium [Ca2+]i during the process of disintegrative globulization. METHODS: Individual fiber cells from the cortex of the adult rat lens were isolated by ... More
Spatiotemporal analysis of calcium dynamics in the nucleus of hamster oocytes.
AuthorsShirakawa H, Miyazaki S
JournalJ Physiol
PubMed ID8814604
'1. Subcellular Ca2+ dynamics inside and around the nucleus of immature hamster oocytes were analysed with confocal Ca2+ imaging. 2. The ratio value between emission intensity of two injected fluorescent Ca2+ indicators, Calcium Green and Fura Red, was almost uniform over the entire oocyte, suggesting that nucleoplasmic Ca2+ concentration ([Ca2+]n) ... More
Nuclear calcium transport and the role of calcium in apoptosis.
AuthorsNicotera P, Zhivotovsky B, Orrenius S
JournalCell Calcium
PubMed ID7820847
'The last decade has been the rapid development of research investigating the molecular mechanisms whereby hormones, peptide growth factors and cytokines regulate cell metabolism, differentiation and proliferation. One general signalling mechanism used to transfer the information delivered by agonists into appropriate intracellular compartments involves the rapid Ca2+ redistribution throughout the ... More
Mechanisms of calcium release and propagation in cardiac cells. Do studies with confocal microscopy add to our understanding?
AuthorsWilliams DA
JournalCell Calcium
PubMed ID8131189
'Laser-scanning confocal microscopy (LSCM) has a number of recognised advantages over other techniques of light microscopy for the study of cell and tissue structure. These include increased image spatial resolution, and even more importantly, removal of out-of-focus information from 2-dimensional images of 3-dimensional structures. Moreover, these features have also recently ... More
Subcellular distribution of Ca2+ release channels underlying Ca2+ waves and oscillations in exocrine pancreas.
AuthorsKasai H, Li YX, Miyashita Y
JournalCell
PubMed ID8395348
'Agonists trigger Ca2+ waves and oscillations in exocrine gland cells. Our confocal Ca2+ imaging revealed three distinct phases during the Ca2+ waves in the rat pancreatic acinar cell. Rises in Ca2+ concentration were initiated at a small trigger zone, or T zone, in the granular area; then, Ca2+ waves rapidly ... More
Integrin alpha IIb beta 3-dependent calcium signals regulate platelet-fibrinogen interactions under flow. Involvement of phospholipase C gamma 2.
AuthorsGoncalves I, Hughan SC, Schoenwaelder SM, Yap CL, Yuan Y, Jackson SP
JournalJ Biol Chem
PubMed ID12832405
'Platelet adhesion to fibrinogen is important for platelet aggregation and thrombus growth. In this study we have examined the mechanisms regulating platelet adhesion on immobilized fibrinogen under static and shear conditions. We demonstrate that integrin alpha IIb beta 3 engagement of immobilized fibrinogen is sufficient to induce an oscillatory calcium ... More
Effects of Equex from different sources on post-thaw survival, longevity and intracellular Ca2+ concentration of dog spermatozoa.
AuthorsPeña AI, Lugilde LL, Barrio M, Herradón PG, Quintela LA
JournalTheriogenology
PubMed ID12566147
'The aims of the present study were to compare the effects of two commercial preparations (Equex STM Paste or Equex Pasta), whose active ingredient is sodium dodecyl sulphate (SDS), added to a Tris-egg yolk-based extender, on post-thaw sperm survival and longevity, as well as on the intracellular Ca(2+) concentration of ... More
Differences in the sensitivity to purinergic stimulation of myelinating and non-myelinating Schwann cells in peripheral human and rat nerve.
AuthorsMayer C, Quasthoff S, Grafe P
JournalGlia
PubMed ID9671967
'Schwann cells of the peripheral nervous system are distinguished by morphological and functional criteria in myelinating and non-myelinating subtypes. We and others have previously reported that Schwann cells in isolated peripheral human and rat nerve respond to extracellular application of ATP with a rise in the intracellular free calcium concentration ... More
Cytosolic calcium changes in a process of platelet adhesion and cohesion on a von Willebrand factor-coated surface under flow conditions.
AuthorsKuwahara M, Sugimoto M, Tsuji S, Miyata S, Yoshioka A
JournalBlood
PubMed ID10438701
'Recent flow studies indicated that platelets are transiently captured onto and then translocated along the surface through interaction of glycoprotein (GP) Ib with surface-immobilized von Willebrand factor (vWF). During translocation, platelets are assumed to be activated, thereafter becoming firmly adhered and cohered on the surface. In exploring the mechanisms by ... More
T cells from Jak3-deficient mice have intact TCR signaling, but increased apoptosis.
AuthorsThomis DC, Lee W, Berg LJ
JournalJ Immunol
PubMed ID9366394
'The Jak family tyrosine kinase, Jak3, is involved in signaling through cytokine receptors utilizing the common gamma-chain (gamma(c)). Mice and humans lacking Jak3 have severe immune deficiencies, including defects in B and T lymphocyte development and function. In particular, Jak3-deficient mice have mature T cells with an activated phenotype, yet ... More
Kinetics of stimulus-coupled secretion in dialyzed bovine chromaffin cells in response to trains of depolarizing pulses.
AuthorsSeward EP, Nowycky MC
JournalJ Neurosci
PubMed ID8551339
'Stimulus-secretion coupling in bovine chromaffin cells was investigated with whole-cell patch-clamp recordings and capacitance detection techniques to monitor exocytosis in response to trains of depolarizing pulses. Two kinetically discrete modes of exocytotic responses were observed. In one mode, the first depolarization of a train elicited a large increase in membrane ... More
Agonist-induced calcium response in single human platelets assayed in a microfluidic device.
'To facilitate drug discovery directed toward platelet-specific targets, we developed a platelet isolation and fluorophore-loading method that yields functionally responsive platelets in which we were able to detect agonist-induced calcium flux using a microfluidics-based screening platform. The platelet preparation protocol was designed to minimize preparation-induced platelet activation and to optimize ... More
Regulation of inositol 1,4,5-trisphosphate 3-kinases by calcium and localization in cells.
'Inositol 1,4,5-trisphosphate (Ins(1,4,5)P(3)) 3-kinases (IP(3)Ks) are a group of calmodulin-regulated inositol polyphosphate kinases (IPKs) that convert the second messenger Ins(1,4,5)P(3) into inositol 1,3,4,5-tetrakisphosphate. However, what they contribute to the complexities of Ca(2+) signaling, and how, is still not fully understood. In this study, we have used a simple Ca(2+) imaging ... More
AuthorsMetkar SS, Wang B, Catalan E, Anderluh G, Gilbert RJ, Pardo J, Froelich CJ,
JournalPLoS One
PubMed ID21931672
'The cytotoxic cell granule secretory pathway is essential for host defense. This pathway is fundamentally a form of intracellular protein delivery where granule proteases (granzymes) from cytotoxic lymphocytes are thought to diffuse through barrel stave pores generated in the plasma membrane of the target cell by the pore forming protein ... More
Prostaglandin E2 enhances osteoclastic differentiation of precursor cells through protein kinase A-dependent phosphorylation of TAK1.
AuthorsKobayashi Y, Mizoguchi T, Take I, Kurihara S, Udagawa N, Takahashi N
JournalJ Biol Chem
PubMed ID15647289
'Prostaglandin E2 (PGE2) synergistically enhances the receptor activator for NF-kappa B ligand (RANKL)-induced osteoclastic differentiation of the precursor cells. Here we investigated the mechanisms of the stimulatory effect of PGE2 on osteoclast differentiation. PGE2 enhanced osteoclastic differentiation of RAW264.7 cells in the presence of RANKL through EP2 and EP4 prostanoid ... More
Microscopic spiral waves reveal positive feedback in subcellular calcium signaling.
AuthorsLipp P, Niggli E
JournalBiophys J
PubMed ID8312468
'The regenerative Ca(2+)-induced Ca2+ release mechanism is an important amplifier of signal transduction in diverse cells. In heart muscle cells, this mechanism contributes to the Ca2+ transient activating the mechanical contraction, but it is also believed to drive Ca2+ waves propagating within the cytosol. We investigated the subcellular Ca2+ distribution ... More
Signal transduction in monocytes and granulocytes measured by multiparameter flow cytometry.
AuthorsLund-Johansen F, Olweus J
JournalCytometry
PubMed ID1451600
'The novel calcium indicator fura red and the oxidative burst indicator dihydrorhodamine (both excited at 488 nm) were used in combination with multiparameter flow cytometry to allow simultaneous kinetic measurements of calcium fluxes and oxidative bursts in monocytes and granulocytes. Using this method it was possible to obtain direct evidence ... More
Improved fluorescent (calcium indicator) dye uptake in brain slices by blocking multidrug resistance transporters.
AuthorsManzini I, Schweer TS, Schild D,
JournalJ Neurosci Methods
PubMed ID17767961
'ATP-binding cassette (ABC) transporters are a family of transmembrane proteins that, also known as multidrug resistance proteins, transport a wide variety of substrates across biological membranes in an energy-dependent manner. Recently it has been shown that members of this protein family interfere with fluorescent (calcium indicator) dye uptake in taste ... More
Calicum microdomains form within neutrophils at the neutrophil-tumor cell synapse: role in antibody-dependent target cell apoptosis.
AuthorsClark AJ, Diamond M, Elfline M, Petty HR,
JournalCancer Immunol Immunother
PubMed ID19593564
'Ca(2+) messages are broadly important in cellular signal transduction. In immune cells, Ca(2+) signaling is an essential step in many forms of activation. Neutrophil-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) is one form of leukocyte activation that plays an important role in tumor cell killing in vitro and in patient care. Using ... More
Calcium mobilization evoked by hepatocellular swelling is linked to activation of phospholipase Cgamma.
AuthorsMoore AL, Roe MW, Melnick RF, Lidofsky SD
JournalJ Biol Chem
PubMed ID12167665
'Recovery from swelling of hepatocytes and selected other epithelia is triggered by intracellular Ca(2+) release from the endoplasmic reticulum, which leads to fluid and electrolyte efflux through volume-sensitive K(+) and Cl(-) channels. The aim of this study was to determine the mechanisms responsible for swelling-mediated hepatocellular Ca(2+) mobilization. Swelling of ... More
A flow cytometric comparison of Indo-1 to fluo-3 and Fura Red excited with low power lasers for detecting Ca(2+) flux.
AuthorsBailey S, Macardle PJ
JournalJ Immunol Methods
PubMed ID16545393
'Indo-1 and high-power water-cooled lasers have been the standard for flow cytometric based Ca(2+) flux measurements. With advances in technology and the availability of low-power air-cooled lasers, there is interest in alternative protocols. Here, we have compared Indo-1 with the combination of fluo-3 and Fura Red calcium indicator dyes using ... More
Calcium signals in olfactory neurons.
AuthorsTareilus E, Noé J, Breer H
JournalBiochim Biophys Acta
PubMed ID7488645
'Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a ... More
Analysis of free intracellular calcium by flow cytometry: multiparameter and pharmacologic applications.
AuthorsBurchiel SW, Edwards BS, Kuckuck FW, Lauer FT, Prossnitz ER, Ransom JT, Sklar LA
JournalMethods
PubMed ID10873476
'Flow cytometry offers numerous advantages over traditional techniques for measuring intracellular Ca(2+) in lymphoid and nonlymphoid cells. In particular, the heterogeneity of cell responses can be defined by flow cytometry, and multiparameter analyses permit the determination of intracellular Ca(2+) in surface-marker-defined target cells as well as correlation of changes in ... More
Flow cytometric analysis of the effects of tri-n-butyltin chloride on cytosolic free calcium and thiol levels in isolated rainbow trout hepatocytes.
AuthorsReader S, Marion M, Denizeau F
JournalToxicology
PubMed ID8327995
'The toxic effects of tri-n-butyltin chloride (TBT) were investigated on isolated trout hepatocytes by flow cytometry (FCM). We developed a procedure permitting the study of cytosolic free calcium in these cells using the new fluorescent probe Fura Red. In parallel, changes in thiol levels upon exposure to TBT were also ... More
Increasing the affinity for tumor antigen enhances bispecific antibody cytotoxicity.
AuthorsMcCall AM, Shahied L, Amoroso AR, Horak EM, Simmons HH, Nielson U, Adams GP, Schier R, Marks JD, Weiner LM
JournalJ Immunol
PubMed ID11342630
'We tested the hypothesis that bispecific Abs (Bsab) with increased binding affinity for tumor Ags augment retargeted antitumor cytotoxicity. We report that an increase in the affinity of Bsab for the HER2/neu Ag correlates with an increase in the ability of the Bsab to promote retargeted cytotoxicity against HER2/neu-positive cell ... More
Regulation of the transient receptor potential channel TRPM2 by the Ca2+ sensor calmodulin.
AuthorsTong Q, Zhang W, Conrad K, Mostoller K, Cheung JY, Peterson BZ, Miller BA
JournalJ Biol Chem
PubMed ID16461353
'TRPM2, a member of the transient receptor potential (TRP) superfamily, is a Ca(2+)-permeable channel activated by oxidative stress or tumor necrosis factoralpha involved in susceptibility to cell death. TRPM2 activation is dependent on the level of intracellular Ca(2+). We explored whether calmodulin (CaM) is the Ca(2+) sensor for TRPM2. HEK ... More
Cold-sensitive Ca2+ influx in Paramecium.
AuthorsKuriu T, Nakaoka Y, Oosawa Y
JournalJ Membr Biol
PubMed ID8929290
'The concentration of intracellular calcium, [Ca2+]i, in Paramecium was imaged during cold-sensitive response by monitoring fluorescence of two calcium-sensitive dyes, Fluo-3 and Fura-Red. Cooling of a deciliated Paramecium caused a transient increase in [Ca2+]i at the anterior region of the cell. Increase in [Ca2+]i was not observed at any region ... More
Slow rise of Ca2+ and slow release of reactive oxygen species are two cross-talked events important in tumour necrosis factor-alpha-mediated apoptosis.
AuthorsKo S, Kwok TT, Fung KP, Choy YM, Lee CY, Kong SK
JournalFree Radic Res
PubMed ID10993483
'Tumour necrosis factor-alpha (TNF-alpha) was found to be a cell cycle-independent apoptogenic cytokine in cultured fibroblast L929 cells. This assertion is based on the observations (1) TNF-alpha increased the number of cells with hypo-diploid DNA in a time dependent manner as revealed by flow cytometry, and (2) TNF-alpha induced DNA ... More
Calcitonin gene-related peptide elevates calcium and polarizes membrane potential in MG-63 cells by both cAMP-independent and -dependent mechanisms.
AuthorsBurns DM, Stehno-Bittel L, Kawase T
JournalAm J Physiol Cell Physiol
PubMed ID15238361
'Published data suggest that the neuropeptide calcitonin gene-related peptide (CGRP) can stimulate osteoblastic bone formation; however, interest has focused on activation of cAMP-dependent signaling pathways in osteogenic cells without full consideration of the importance of cAMP-independent signaling. We have now examined the effects of CGRP on intracellular Ca(2+) concentration ([Ca(2+)](int)) ... More
Stimulation of CD95 (Fas) blocks T lymphocyte calcium channels through sphingomyelinase and sphingolipids.
AuthorsLepple-Wienhues A, Belka C, Laun T, Jekle A, Walter B, Wieland U, Welz M, Heil L, Kun J, Busch G, Weller M, Bamberg M, Gulbins E, Lang F
JournalProc Natl Acad Sci U S A
PubMed ID10570152
'Calcium influx through store-operated calcium release-activated calcium channels (CRAC) is required for T cell activation, cytokine synthesis, and proliferation. The CD95 (Apo-1/Fas) receptor plays a role in self-tolerance and tumor immune escape, and it mediates apoptosis in activated T cells. In this paper we show that CD95-stimulation blocks CRAC and ... More
Localized Ca2+ uncaging reveals polarized distribution of Ca2+-sensitive Ca2+ release sites: mechanism of unidirectional Ca2+ waves.
AuthorsAshby MC, Craske M, Park MK, Gerasimenko OV, Burgoyne RD, Petersen OH, Tepikin AV
JournalJ Cell Biol
PubMed ID12119355
'Ca2+-induced Ca2+ release (CICR) plays an important role in the generation of cytosolic Ca2+ signals in many cell types. However, it is inherently difficult to distinguish experimentally between the contributions of messenger-induced Ca2+ release and CICR. We have directly tested the CICR sensitivity of different regions of intact pancreatic acinar ... More
Different spatial patterns of [Ca2+] increase caused by N- and L-type Ca2+ channel activation in frog olfactory bulb neurones.
AuthorsBischofberger J, Schild D
JournalJ Physiol
PubMed ID8558465
'1. The intracellular calcium concentration ([Ca2+]i) in cultured olfactory bulb neurones of Xenopus laevis tadpoles was imaged using the calcium indicator dyes fluo-3 and Fura Red as well as a laser scanning microscope. 2. Upon extracellular application of brief pulses of a solution with high potassium concentration (high [K+]o), an ... More
Confocal calcium imaging reveals an ionotropic P2 nucleotide receptor in the paranodal membrane of rat Schwann cells.
AuthorsGrafe P, Mayer C, Takigawa T, Kamleiter M, Sanchez-Brandelik R
JournalJ Physiol
PubMed ID10050005
'1. The paranodal Schwann cell region is of major importance for the function of a myelinated axon. In the present study we searched for a possible ionotropic effect of extracellular ATP in this Schwann cell compartment. 2. Whole-cell patch-clamp recordings from cultured rat Schwann cells revealed that ATP and 2''-3''-O-(4-benzoylbenzoyl)-adenosine ... More
In situ imaging of intracellular calcium with ischemia in lung subpleural microvascular endothelial cells.
AuthorsTozawa K, al-Mehdi AB, Muzykantov V, Fisher AB
JournalAntioxid Redox Signal
PubMed ID11228743
'We propose that generation of reactive oxygen species (ROS) during ischemia is associated with an increase in intracellular calcium ([Ca2+]i) in pulmonary capillary endothelial cells. We used an isolated rat lung model and epifluorescence microscopy to evaluate [Ca2+]i in subpleural microvascular endothelial cells in situ by ratio imaging of the ... More
Lipid length controls antigen entry into endosomal and nonendosomal pathways for CD1b presentation.
AuthorsMoody DB, Briken V, Cheng TY, Roura-Mir C, Guy MR, Geho DH, Tykocinski ML, Besra GS, Porcelli SA
JournalNat Immunol
PubMed ID11938350
'CD1 proteins present various glycolipid antigens to T cells, but the cellular mechanisms that control which particular glycolipids generate T cell responses are not understood. We show here that T cell recognition of glucose monomycolate antigens with long (C(80)) alkyl chains involves the delivery of CD1b proteins and antigens to ... More
Intracellular calcium transients mediated by P2 receptors in the paranodal Schwann cell region of myelinated rat spinal root axons.
AuthorsMayer C, Wächtler J, Kamleiter M, Grafe P
JournalNeurosci Lett
PubMed ID9132688
'Receptors for neuroligands in the paranodal Schwann cell region of a myelinated nerve fiber could have important functions. We have used confocal laser scanning microscopy in combination with Ca(2+)-sensitive fluorescent dyes to study the possible effects of purinergic agonists on the free intracellular calcium concentration ([Ca2+]i) in paranodes of isolated ... More
In situ biochemical demonstration that P-glycoprotein is a drug efflux pump with broad specificity.
AuthorsChen Y, Simon SM
JournalJ Cell Biol
PubMed ID10704438
'While P-glycoprotein (Pgp) is the most studied protein involved in resistance to anti-cancer drugs, its mechanism of action is still under debate. Studies of Pgp have used cell lines selected with chemotherapeutics which may have developed many mechanisms of resistance. To eliminate the confounding effects of drug selection on understanding ... More
Intracellular ionized calcium.
AuthorsJune CH, Rabinovitch PS
JournalMethods Cell Biol
PubMed ID7861962
Measuring cytosolic Ca2+ in cells with fluorescent probes: an aid to understanding cell pathophysiology.
AuthorsHayes A, Cody SH, Williams DA
JournalInt Rev Exp Pathol
PubMed ID8860943
Use of confocal microscopy to investigate cell structure and function.
AuthorsBkaily G, Jacques D, Pothier P
JournalMethods Enzymol
PubMed ID10506971
The use of confocal microscopy in the investigation of cell structure and function in the heart, vascular endothelium and smooth muscle cells.
AuthorsBkaily G, Pothier P, D'Orléans-Juste P, Simaan M, Jacques D, Jaalouk D, Belzile F, Hassan G, Boutin C, Haddad G, Neugebauer W
JournalMol Cell Biochem
PubMed ID9278244
In recent years, fluorescence microscopy imaging has become an important tool for studying cell structure and function. This non invasive technique permits characterization, localisation and qualitative quantification of free ions, messengers, pH, voltage and a pleiad of other molecules constituting living cells. In this paper, we present results using various ... More
AuthorsParravicini V, Gadina M, Kovarova M, Odom S, Gonzalez-Espinosa C, Furumoto Y, Saitoh S, Samelson LE, O'Shea JJ, Rivera J
JournalNat Immunol
PubMed ID12089510
Fc epsilon RI activation of mast cells is thought to involve Lyn and Syk kinases proximal to the receptor and the signaling complex organized by the linker for activation of T cells (LAT). We report here that Fc epsilon RI also uses a Fyn kinase-dependent pathway that does not require ... More
P2 purinoceptor-mediated intracellular Ca2+ transients in human sural nerve.
AuthorsWächtler J, Mayer C, Quasthoff S, Adelsberger H, Grafe P
JournalNeuroreport
PubMed ID8817551
Segments of biopsied human sural nerve were stained with the Ca(2+)-sensitive fluorescent dyes Calcium Green-1 and Fura Red. The emission ratio was used to follow changes in the intracellular free Ca2+ concentration ([Ca2+]i). Application of ATP and analogues in concentrations between 0.3 and 300 microM via the bathing solution resulted ... More
Spatial characterisation of ryanodine-induced calcium release in mouse pancreatic acinar cells.
AuthorsAshby MC, Petersen OH, Tepikin AV
JournalBiochem J
PubMed ID12444927
In pancreatic acinar cells, agonists evoke intracellular Ca(2+) transients which are initiated in the apical region of these polarized cells. There are contradictory experimental data concerning Ca(2+) release from ryanodine receptors (RyRs) in the apical region. In the present study, we have used low doses of ryanodine to open RyRs ... More
New statistical methods enhance imaging of cameleon fluorescence resonance energy transfer in cultured zebrafish spinal neurons.
AuthorsFan X, Majumder A, Reagin SS, Porter EL, Sornborger AT, Keith CH, Lauderdale JD
JournalJ Biomed Opt
PubMed ID17614725
Cameleons are genetically encoded fluorescence resonance energy transfer (FRET)-based Ca(2+) indicators. Attempts to use cameleons to detect neural activity in vertebrate systems have been largely frustrated by the small FRET signal, in contradistinction to the higher signals seen in Drosophila and Caenorhabditis elegans. We have developed a statistical optimization method ... More
Noninvasive in vivo imaging of pancreatic islet cell biology.
AuthorsSpeier S, Nyqvist D, Cabrera O, Yu J, Molano RD, Pileggi A, Moede T, Köhler M, Wilbertz J, Leibiger B, Ricordi C, Leibiger IB, Caicedo A, Berggren PO,
JournalNat Med
PubMed ID18327249
Advanced imaging techniques have become a valuable tool in the study of complex biological processes at the cellular level in biomedical research. Here, we introduce a new technical platform for noninvasive in vivo fluorescence imaging of pancreatic islets using the anterior chamber of the eye as a natural body window. ... More
A new technique for assessing the microscopic distribution of cellular calcium exit sites.
AuthorsBelan PV, Gerasimenko OV, Berry D, Saftenku E, Petersen OH, Tepikin AV
JournalPflugers Arch
PubMed ID9019724
This paper contains a description of a new method designed to monitor the distribution of Ca2+ efflux from cells or small cellular aggregates. The idea behind this method is to use a fluorescent Ca2+ indicator bound to dextrans of high molecular weight to slow down Ca2+ diffusion. Due to the ... More
Sodium/calcium exchanger in rat olfactory neurons.
AuthorsNoé J, Tareilus E, Boekhoff I, Breer H
JournalNeurochem Int
PubMed ID9152993
The chemo-electrical transduction process in olfactory neurons is accompanied by a rapid and transient increase in intracellular calcium concentrations. The notion that Na+/Ca2+ exchanger activities may play a major role in extruding calcium ions out of the cell and maintaining Ca2+ homeostasis in olfactory receptor cells was assessed by means ... More
Filopodia that extend from neuronal growth cones sample the environment for extracellular guidance cues, but the signals they transmit to growth cones are unknown. Filopodia were observed generating localized transient elevations of intracellular calcium ([Ca2+]i) that propagate back to the growth cone and stimulate global Ca2+ elevations. The frequency of ... More
Stable Golgi-mitochondria complexes and formation of Golgi Ca(2+) gradients in pancreatic acinar cells.
We have determined the localization of the Golgi with respect to other organelles in living pancreatic acinar cells and the importance of this localization to the establishment of Ca(2+) gradients over the Golgi. Using confocal microscopy and the Golgi-specific fluorescent probe 6-((N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)hexanoyl)sphingosine, we found Golgi structures localizing to the outer ... More
An engineered GM-CSF-CCL2 fusokine is a potent inhibitor of CCR2-driven inflammation as demonstrated in a murine model of inflammatory arthritis.
AuthorsRafei M, Berchiche YA, Birman E, Boivin MN, Young YK, Wu JH, Heveker N, Galipeau J,
JournalJ Immunol
PubMed ID19592643
CCR2 is a chemokine receptor widely expressed by lymphomyeloid cells involved in maladaptive autoimmune ailments. Therefore CCR2 is of great interest as a biological target for immune suppression due to its direct implication in autoimmune diseases such as rheumatoid arthritis. We have generated a novel fusion protein using GM-CSF and ... More
Uses and future applications of flow cytometry in immunotoxicity testing.
AuthorsBurchiel SW, Lauer FT, Gurulé D, Mounho BJ, Salas VM
JournalMethods
PubMed ID10525435
Flow cytometry is an emerging technology that has numerous applications to immunotoxicity testing. The use and development of high-speed single-cell laser-based assays capable of quantitation of fluorescence, light scatter, and electrical impedance measurements can provide important information on xenobiotic-induced toxicity in defined target cell populations. The purpose of this article ... More
Calcium mediates bidirectional growth cone turning induced by myelin-associated glycoprotein.
AuthorsHenley JR, Huang KH, Wang D, Poo MM
JournalNeuron
PubMed ID15603734
Cytoplasmic second messengers, Ca2+ and cAMP, regulate nerve growth cone turning responses induced by many guidance cues, but the causal relationship between these signaling pathways has been unclear. We here report that, for growth cone turning induced by a gradient of myelin-associated glycoprotein (MAG), cAMP acts by modulating MAG-induced Ca2+ ... More
Localization of Ca2+ extrusion sites in pancreatic acinar cells.
We have investigated the localization of Ca2+ extrusion sites in mouse pancreatic acinar cells. Employing a new technique, in which high resolution localization of cellular Ca2+ exit is achieved by confocal microscopy and a Ca2+-sensitive fluorescent probe coupled to heavy dextran to slow down diffusion of extracellular Ca2+, it is ... More
Simultaneous dual-excitation ratiometry using orthogonal linear polarized lights.
AuthorsFukano T, Shimozono S, Miyawaki A
JournalBiochem Biophys Res Commun
PubMed ID15047150
Dual-excitation ratiometric dyes permit quantitative Ca2+ measurements by minimizing the effects of several artifacts that are unrelated to changes in the concentration of free Ca2+ ([Ca2+]). These dyes are excited alternately at two different wavelengths, and the pair of intensity measurements must be collected sequentially. Therefore, it is difficult to ... More
Quantum dot/peptide-MHC biosensors reveal strong CD8-dependent cooperation between self and viral antigens that augment the T cell response.
AuthorsAnikeeva N, Lebedeva T, Clapp AR, Goldman ER, Dustin ML, Mattoussi H, Sykulev Y
JournalProc Natl Acad Sci U S A
PubMed ID17077145
Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a myriad of virus-unrelated endogenous self pMHC-I complexes displayed on virus-infected cells. To elucidate the molecular recognition events on live CTL, we have utilized a self-assembled biosensor composed of semiconductor nanocrystals, quantum dots, carrying a controlled ... More
Calreticulin modulates capacitative Ca2+ influx by controlling the extent of inositol 1,4,5-trisphosphate-induced Ca2+ store depletion.
AuthorsXu W, Longo FJ, Wintermantel MR, Jiang X, Clark RA, DeLisle S
JournalJ Biol Chem
PubMed ID10973951
Calreticulin (CRT) is a highly conserved Ca(2+)-binding protein that resides in the lumen of the endoplasmic reticulum (ER). We overexpressed CRT in Xenopus oocytes to determine how it could modulate inositol 1,4,5-trisphosphate (InsP(3))-induced Ca(2+) influx. Under conditions where it did not affect the spatially complex elevations in free cytosolic Ca(2+) ... More
Changes in subsarcolemmal sodium concentration measured by Na-Ca exchanger activity during Na-pump inhibition and beta-adrenergic stimulation in guinea-pig ventricular myocytes.
AuthorsMain MJ, Grantham CJ, Cannell MB
JournalPflugers Arch
PubMed ID9359910
Measurement of Na-Ca exchange activity was used to examine subsarcolemmal sodium levels ([Na+]s) in single, voltage-clamped guinea-pig cardiac myocytes while Na-K pump activity was modulated pharmacologically. Changes in Nas were evaluated from phase-plane analysis of the changes in intracellular calcium, measured using the fluorescent indicators Fura-red and Fluo-3. Activation of ... More
Improved sensitivity in flow cytometric intracellular ionized calcium measurement using fluo-3/Fura Red fluorescence ratios.
AuthorsNovak EJ, Rabinovitch PS
JournalCytometry
PubMed ID7835163
Measurement of changes in intracellular ionized calcium concentrations ([Ca2+]i) has proved to be of wide use in the study of cellular responses to activating stimuli. The fluorescent dye Indo-1 has successfully been used in flow cytometry for this purpose, and when used as a ratiometric indicator it provides optimum sensitivity ... More
Critical intracellular Ca2+ concentration for all-or-none Ca2+ spiking in single smooth muscle cells.
AuthorsIino M, Yamazawa T, Miyashita Y, Endo M, Kasai H
JournalEMBO J
PubMed ID8262071
Neurotransmitters induce contractions of smooth muscle cells initially by mobilizing Ca2+ from intracellular Ca2+ stores through inositol 1,4,5-trisphosphate (InsP3) receptors. Here we studied roles of the molecules involved in Ca2+ mobilization in single smooth muscle cells. A slow rise in cytoplasmic Ca2+ ([Ca2+]i) in agonist-stimulated smooth muscle cells was followed ... More
NAADP, cADPR and IP3 all release Ca2+ from the endoplasmic reticulum and an acidic store in the secretory granule area.
AuthorsGerasimenko JV, Sherwood M, Tepikin AV, Petersen OH, Gerasimenko OV
JournalJ Cell Sci
PubMed ID16410548
Inositol trisphosphate and cyclic ADP-ribose release Ca2+ from the endoplasmic reticulum via inositol trisphosphate and ryanodine receptors, respectively. By contrast, nicotinic acid adenine dinucleotide phosphate may activate a novel Ca2+ channel in an acid compartment. We show, in two-photon permeabilized pancreatic acinar cells, that the three messengers tested could each ... More
Ca2+ sparks and Ca2+ waves activate different Ca(2+)-dependent ion channels in single myocytes from rat portal vein.
AuthorsMironneau J, Arnaudeau S, Macrez-Lepretre N, Boittin FX
JournalCell Calcium
PubMed ID8889206
Ca2+ release from intracellular stores was examined with the use of a confocal microscope in single, voltage-clamped myocytes from rat portal vein loaded with both Fluo-3 and Fura-red. Spontaneous local increases in [Ca2+]i from the sarcoplasmic reticulum, termed Ca2+ sparks, were observed in about 30% of the quiescent cells tested. ... More
Transgenic mice with green fluorescent protein-labeled pancreatic beta -cells.
AuthorsHara M, Wang X, Kawamura T, Bindokas VP, Dizon RF, Alcoser SY, Magnuson MA, Bell GI
JournalAm J Physiol Endocrinol Metab
PubMed ID12388130
We have generated transgenic mice that express green fluorescent protein (GFP) under the control of the mouse insulin I gene promoter (MIP). The MIP-GFP mice develop normally and are indistinguishable from control animals with respect to glucose tolerance and pancreatic insulin content. Histological studies showed that the MIP-GFP mice had ... More
Calcium imaging of murine thoracic aorta endothelium by confocal microscopy reveals inhomogeneous distribution of endothelial cells responding to vasodilator agents.
AuthorsMarie I, Bény JL
JournalJ Vasc Res
PubMed ID12097824
The aim of the study was to assess, in intact murine thoracic aorta in vitro, the distribution of endothelial cells responsive to endothelium-dependent vasodilators ACh, ATP, bradykinin and substance P, using laser line confocal microscopy in combination with two Ca2+ fluorescent dyes, Fluo-4 and Fura-red. We observed that 82 +/- ... More
Preformed oligomeric epidermal growth factor receptors undergo an ectodomain structure change during signaling.
AuthorsMartin-Fernandez M, Clarke DT, Tobin MJ, Jones SV, Jones GR
JournalBiophys J
PubMed ID11964230
Fluorescence resonance energy transfer (FRET) was used to reveal aspects of the mechanism of signal transduction by epidermal growth factor receptors (EGFR). The superpositions of epidermal growth factor (EGF), transforming growth factor-alpha (TGFalpha) and an antibody fragment (29.1) to the carbohydrate extremity of the receptor's ectodomain as measured by FRET, ... More
Real-time imaging of nuclear permeation by EGFP in single intact cells.
AuthorsWei X, Henke VG, Strübing C, Brown EB, Clapham DE
JournalBiophys J
PubMed ID12547812
The NPC is the portal for the exchange of proteins, mRNA, and ions between nucleus and cytoplasm. Many small molecules (<10 kDa) permeate the nucleus by simple diffusion through the pore, but molecules larger than 70 kDa require ATP and a nuclear localization sequence for their transport. In isolated Xenopus ... More
Rapid internalization and surface expression of a functional, fluorescently tagged G-protein-coupled glutamate receptor.
AuthorsDoherty AJ, Coutinho V, Collingridge GL, Henley JM
JournalBiochem J
PubMed ID10393101
l-Glutamate is the principal excitatory neurotransmitter in the vertebrate central nervous system, where it mediates many of its actions via G-protein-coupled metabotropic glutamate (mGlu) receptors. Since little is known about the dynamics of mGlu receptors at the plasma membrane, we have constructed a fusion protein comprising the mGlu receptor subtype ... More
Purinergic receptors have different effects in rat exocrine pancreas. Calcium signals monitored by fura-2 using confocal microscopy.
AuthorsNovak I, Nitschke R, Amstrup J
JournalCell Physiol Biochem
PubMed ID12077553
Pancreatic ducts have several types of purinergic P2 receptors, however, nothing is known about P2 receptors in acini. The aim was to establish whether acini express functional P2 receptors coupled to intracellular Ca2+ signals and to measure the signals ratiometrically in a confocal laser scanning microscope. Rat acini and ducts ... More
Role of smooth muscle cells on endothelial cell cytosolic free calcium in porcine coronary arteries.
AuthorsBudel S, Schuster A, Stergiopoulos N, Meister JJ, Bény JL
JournalAm J Physiol Heart Circ Physiol
PubMed ID11514282
We tested the hypothesis that the cytosolic free calcium concentration in endothelial cells is under the influence of the smooth muscle cells in the coronary circulation. In the left descending branch of porcine coronary arteries, cytosolic free calcium concentration ([Ca(2+)](i)) was estimated by determining the fluorescence ratio of two calcium ... More
Imaging of calcium release in inositol 1,4,5-trisphosphate-sensitive internal stores in permeabilized HSY cells using fluorescent indicators.
AuthorsTanimura A, Tojyo Y, Matsumoto Y, Yajima T
JournalCell Struct Funct
PubMed ID9639024
We described methods for imaging the IP3-induced Ca2+ release in Ca2+ storage organelles. IP3-induced changes in Ca2+ concentrations within Ca2+ stores ([Ca2+]L) in permeabilized HSY cells were monitored using the low affinity Ca2+ indicators, mag-fura-2 and mag-fura-red. The ratio images of mag-fura-2 were used to estimate the [Ca2+]L in the ... More
New aspects of nuclear calcium signalling.
AuthorsGerasimenko O, Gerasimenko J
JournalJ Cell Sci
PubMed ID15226390
Nuclear calcium signalling has been a controversial battlefield for many years and the question of how permeable the nuclear pore complexes (NPCs) are to Ca2+ has been the subject of a particularly hot dispute. Recent data from isolated nuclei suggest that the NPCs are open even after depletion of the ... More
T cell receptor ligation induces the formation of dynamically regulated signaling assemblies.
AuthorsBunnell SC, Hong DI, Kardon JR, Yamazaki T, McGlade CJ, Barr VA, Samelson LE
JournalJ Cell Biol
PubMed ID12356870
Tcell antigen receptor (TCR) ligation initiates tyrosine kinase activation, signaling complex assembly, and immune synapse formation. Here, we studied the kinetics and mechanics of signaling complex formation in live Jurkat leukemic T cells using signaling proteins fluorescently tagged with variants of enhanced GFP (EGFP). Within seconds of contacting coverslips coated ... More
Intracellular Mg2+ surge follows Ca2+ increase during depolarization in cultured neurons.
AuthorsGotoh H, Kajikawa M, Kato H, Suto K
JournalBrain Res
PubMed ID10320737
The intracellular magnesium and calcium concentrations in cultured dorsal root ganglion neurons were measured using a fluorescent Mg2+ indicator, Mag-Fura-2 and a Ca2+ indicator, Fura-2, respectively. The magnesium concentration in the cytoplasm was higher than that in the nuclei at rest; 0.68+/-0.10 mM (mean+/-S.E.M., n=7) in the cytoplasm and 0.11+/-0.05 ... More
Confocal ratiometric voltage imaging of cultured human keratinocytes reveals layer-specific responses to ATP.
Recent evidence suggests that changes in membrane potential influence the proliferation and differentiation of keratinocytes. To further elucidate the role of changes in membrane potential for their biological fate, the electrical behavior of keratinocytes needs to be studied under complex conditions such as multilayered cultures. However, electrophysiological recordings from cells ... More
Cytosolic-free calcium in smooth-muscle and endothelial cells in an intact arterial wall from rat mesenteric artery in vitro.
AuthorsOishi H, Budel S, Schuster A, Stergiopulos N, Meister JJ, Bény JL
JournalCell Calcium
PubMed ID11587550
The regulation of cytosolic-free calcium concentration of smooth-muscle and endothelial cells was mainly studied on cultured cells where the cross talk between these two coupled cell types is lost. In the present study, the cytosolic-free calcium concentration in the endothelial and the smooth-muscle cells was examined in an intact arterial ... More
Neuroligand-mediated calcium signaling in cultured human schwannoma cells.
AuthorsMayer C, Kamleiter M, Sanchez-Brandelik R, Rosenbaum C, Kluwe L, Hanemann CO, Grafe P
JournalJ Peripher Nerv Syst
PubMed ID10442685
Intracellular Ca2+ release regulates proliferation of nonexcitable cells, however, it is not known whether and which neuroligands modulate the free intracellular Ca2+ concentration in human schwannoma cells. Confocal laser scanning microscopy was used for the study of neuroligand-induced Ca2+ signaling in cultured human schwannoma cells loaded with the Ca2+-sensitive fluorescent ... More
Long distance communication between muscarinic receptors and Ca2+ release channels revealed by carbachol uncaging in cell-attached patch pipette.
AuthorsAshby MC, Camello-Almaraz C, Gerasimenko OV, Petersen OH, Tepikin AV
JournalJ Biol Chem
PubMed ID12657637
We have investigated the characteristics of cytosolic Ca2+ signals induced by muscarinic receptor activation of pancreatic acinar cells that reside within intact pancreatic tissue. We show that these cells exhibit global Ca2+ waves and local apical Ca2+ spikes. This is the first evidence for local Ca2+ signaling in undissociated pancreatic ... More
Use of co-loaded Fluo-3 and Fura Red fluorescent indicators for studying the cytosolic Ca(2+)concentrations distribution in living plant tissue.
AuthorsWalczysko P, Wagner E, Albrechtová JT
JournalCell Calcium
PubMed ID10942701
A method for visualisation of cytosolic [Ca(2+)] distribution was applied to living plant tissue. A mixture of the fluorescent probes Fluo-3 and Fura Red was used. The emitted fluorescence was scanned simultaneously in two channels with a laser-scanning confocal microscope and rationing was performed. The homogeneity of the Fluo-3/Fura Red ... More
Prostaglandin F2alpha potentiates the calcium dependent activation of mitochondrial metabolism in luteal cells.
AuthorsPitter JG, Szanda G, Duchen MR, Spät A
JournalCell Calcium
PubMed ID15541462
Cytoplasmic Ca2+ signals are transferred to the mitochondria and activate the Krebs cycle. We have compared the efficiency of this process for two Ca2+ mobilising agonists, PGF2alpha and ATP (acting at metabotropic P2 receptors) in rat luteal cells. [Ca2+]c, [Ca2+]m and mitochondrial NAD(P)H were monitored by means of microspectrofluorimetry and ... More
Subcellular compartmentalization of activation and desensitization of responses mediated by NK2 neurokinin receptors.
AuthorsVollmer JY, Alix P, Chollet A, Takeda K, Galzi JL
JournalJ Biol Chem
PubMed ID10608858
A functional fluorescent neurokinin NK2 receptor was constructed by joining enhanced green fluorescent protein to the amino-terminal end of the rat NK2 receptor and was expressed in human embryonic kidney cells. On cell suspensions, the binding of fluorescent Bodipy-labeled neurokinin A results in a saturatable and reversible decrease of NK2 ... More
Glucose availability alters ischaemia-induced changes in intracellular pH and calcium of isolated rat spinal roots.
AuthorsWächtler J, Mayer C, Rucker F, Grafe P
JournalBrain Res
PubMed ID8828583
Peripheral nerves in diabetic patients show an enhanced liability to ischaemic lesions. Using an in vitro model, we have now analysed the possible role of intracellular proton (pHi) and calcium concentrations ([Ca2+]i) for the pathophysiology of this phenomenon. Isolated rat spinal roots were preincubated for 3 to 6 h in ... More
Simultaneous monitoring of Zn2+ secretion and intracellular Ca2+ from islets and islet cells by fluorescence microscopy.
A method for simultaneously imaging Zn2+ secretion and intracellular Ca2+ at beta-cell clusters and single islets of Langerhans was developed. Cells were loaded with the Ca2+ indicator Fura Red, incubated in buffer containing the Zn2+ indicator FluoZin-3, and imaged via laser scanning fluorescence confocal microscopy. FluoZin-3 and Fura Red are ... More
Viral FLIP impairs survival of activated T cells and generation of CD8+ T cell memory.
AuthorsWu Z, Roberts M, Porter M, Walker F, Wherry EJ, Kelly J, Gadina M, Silva EM, DosReis GA, Lopes MF, O'Shea J, Leonard WJ, Ahmed R, Siegel RM
JournalJ Immunol
PubMed ID15128821
Viral FLIPs (vFLIPs) interfere with apoptosis signaling by death-domain-containing receptors in the TNFR superfamily (death receptors). In this study, we show that T cell-specific transgenic expression of MC159-vFLIP from the human Molluscum contagiosum virus blocks CD95-induced apoptosis in thymocytes and peripheral T cells, but also impairs postactivation survival of in ... More
Confocal imaging reveals activity-dependent intracellular Ca2+ transients in nociceptive human C fibres.
AuthorsMayer C, Quasthoff S, Grafe P
JournalPain
PubMed ID10431719
Unmyelinated nociceptive fibres are a key element in the human nociceptive system, however, it is very difficult to investigate such fibres in vivo in more detail. An alternate approach are studies on isolated human nerves. Here we describe that confocal Ca2+ imaging reveals new information about the physiology of human ... More
Blockage of voltage-gated calcium signaling impairs migration of glial cells in vivo.
AuthorsLohr C, Heil JE, Deitmer JW
JournalGlia
PubMed ID15712206
Migration of glial cells is an essential step in the development of the antennal lobe, the primary olfactory center of insects, to establish well-defined borders between olfactory glomeruli required for odor discrimination. In the present study, we used two-photon microscopy to visualize calcium signaling in developing antennal lobe glial cells ... More