Histamine regulates cytokine production in maturing dendritic cells, resulting in altered T cell polarization.
AuthorsMazzoni A, Young HA, Spitzer JH, Visintin A, Segal DM
JournalJ Clin Invest
PubMed ID11748270
'Atopic diseases such as allergy and asthma are characterized by increases in Th2 cells and serum IgE antibodies. The binding of allergens to IgE on mast cells triggers the release of several mediators, of which histamine is the most prevalent. Here we show that histamine, together with a maturation signal, ... More
Recombinant expression of the plasma membrane Na(+)/Ca(2+) exchanger affects local and global Ca(2+) homeostasis in Chinese hamster ovary cells.
AuthorsBrini M, Manni S, Carafoli E
JournalJ Biol Chem
PubMed ID12145298
'The cardiac type Na(+)/Ca(2+) exchanger (NCX1) has been transiently expressed in Chinese hamster ovary cells, which do not contain an endogenous exchanger, together with aequorin chimeras that are targeted to different intracellular compartments to investigate intracellular Ca(2+) homeostasis. The expression of NCX decreased the endoplasmic reticulum Ca(2+) concentration, [Ca(2+)](er), in ... More
Signaling alterations in activation-induced nonresponsive CD8 T cells.
AuthorsTham EL, Mescher MF
JournalJ Immunol
PubMed ID11489986
'Costimulation-dependent production and autocrine use of IL-2 by activated CD8 T cells results in initial clonal expansion, but this is transient. The cells quickly become anergic, unable to produce IL-2 in response to Ag and costimulation, irrespective of the form of costimulation. This activation-induced non-responsiveness (AINR) differs from "classical" anergy ... 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
Differences in regulation between nuclear and cytoplasmic Ca2+ in cultured smooth muscle cells.
AuthorsHimpens B, De Smedt H, Droogmans G, Casteels R
JournalAm J Physiol
PubMed ID1386189
'The free Ca2+ concentrations in the nucleus ([Ca2+]n) and cytoplasm ([Ca2+]c) of cultured smooth muscle cells were estimated using the fluorescent dye indo-1 and the ACAS 570 confocal laser microscope. In resting DDT1MF2 smooth muscle cells [Ca2+]n was found to be lower than [Ca2+]c. Both values increased transiently in response ... More
Influx of calcium through a redox-sensitive plasma membrane channel in thymocytes causes early necrotic cell death induced by the epipolythiodioxopiperazine toxins.
Authors Hurne Alanna M; Chai Christina L L; Moerman Katherine; Waring Paul;
JournalJ Biol Chem
PubMed ID12063251
'Gliotoxin, a member of the epipolythiodioxopiperazine (ETP) class of toxins, induces both apoptotic and necrotic cell death in a concentration-dependent manner. Whereas the specific trigger for apoptotic death caused by these toxins is unclear, the reactive disulfide bond in the ETP toxins is required for biological activity. Thus it is ... More
Endogenously expressed Trp1 is involved in store-mediated Ca2+ entry by conformational coupling in human platelets.
AuthorsRosado JA, Brownlow SL, Sage SO
JournalJ Biol Chem
PubMed ID12196544
'Physical interaction between transient receptor potential (Trp) channels and inositol 1,4,5-trisphosphate receptors (IP(3)Rs) has been presented as a candidate mechanism for the activation of store-mediated Ca(2+) entry. The role of a human homologue of Drosophila transient receptor potential channel, hTrp1, in the conduction of store-mediated Ca(2+) entry was examined in ... More
The Ca2+ dynamics of isolated mouse beta-cells and islets: implications for mathematical models.
AuthorsZhang M, Goforth P, Bertram R, Sherman A, Satin L
JournalBiophys J
PubMed ID12719219
'[Ca(2+)](i) and electrical activity were compared in isolated beta-cells and islets using standard techniques. In islets, raising glucose caused a decrease in [Ca(2+)](i) followed by a plateau and then fast (2-3 min(-1)), slow (0.2-0.8 min(-1)), or a mixture of fast and slow [Ca(2+)](i) oscillations. In beta-cells, glucose transiently decreased and ... More
Induction of maturation-promoting factor during Xenopus oocyte maturation uncouples Ca(2+) store depletion from store-operated Ca(2+) entry.
AuthorsMachaca K, Haun S
JournalJ Cell Biol
PubMed ID11781335
'During oocyte maturation, eggs acquire the ability to generate specialized Ca(2+) signals in response to sperm entry. Such Ca(2+) signals are crucial for egg activation and the initiation of embryonic development. We examined the regulation during Xenopus oocyte maturation of store-operated Ca(2+) entry (SOCE), an important Ca(2+) influx pathway in ... More
Depletion of calcium stores in injured sensory neurons: anatomic and functional correlates.
AuthorsGemes G, Rigaud M, Weyker PD, Abram SE, Weihrauch D, Poroli M, Zoga V, Hogan QH,
JournalAnesthesiology
PubMed ID19602957
'BACKGROUND: Painful nerve injury leads to disrupted Ca signaling in primary sensory neurons, including decreased endoplasmic reticulum (ER) Ca storage. This study examines potential causes and functional consequences of Ca store limitation after injury. METHODS: Neurons were dissociated from axotomized fifth lumbar (L5) and the adjacent L4 dorsal root ganglia ... More
Protein kinase C mediates insulin-inhibited Ca2+ transport and contraction of vascular smooth muscle.
AuthorsKahn AM, Allen JC, Seidel CL, Song T
JournalAm J Hypertens
PubMed ID10821340
'Insulin acutely inhibits contraction of primary cultured vascular smooth muscle (VSM) cells from canine femoral artery by inhibiting contractile agonist-induced Ca2+ influx. Insulin also inhibits contraction at step(s) distal to intracellular Ca2+ concentration (Ca2+i) by stimulating cyclic guanosine monophosphate (GMP) production. We wished to see whether these effects of insulin ... More
Mechanism and specificity of lanthanide series cation transport by ionophores A23187, 4-BrA23187, and ionomycin.
AuthorsWang E, Taylor RW, Pfeiffer DR
JournalBiophys J
PubMed ID9726927
'A23187, 4-BrA23187, and ionomycin transport several lanthanide series trivalent cations at efficiencies similar to Ca2+, when compared at cation concentrations of approximately 10(-5) M, ionophore concentrations of approximately 10(-6) M, and a pH of 7.00. Selectivity sequences and the range of relative rates are as follows: A23187, Nd3+ > La3+ ... More
Extracellular ATP-induced inward current in isolated epithelial cells of the endolymphatic sac.
AuthorsWu D, Mori N
JournalBiochim Biophys Acta
PubMed ID10366668
'Using whole-cell patch-clamp technique and Fura-2 fluorescence measurement, the presence of ATP-activated ion channels and its dependence on intracellular Ca2+ concentration ([Ca2+]i) in the epithelial cells of the endolymphatic sac were investigated. In zero current-clamp configuration, the average resting membrane potential was -66.8+/-1.3 mV (n=18). Application of 30 microM ATP ... More
Unique signaling properties of B cell antigen receptor in mature and immature B cells: implications for tolerance and activation.
AuthorsBenschop RJ, Brandl E, Chan AC, Cambier JC
JournalJ Immunol
PubMed ID11591737
'Immature B cells display increased sensitivity to tolerance induction compared with their mature counterparts. The molecular mechanisms underlying these differences are poorly defined. In this study, we demonstrate unique maturation stage-dependent differences in B cell Ag receptor (BCR) signaling, including BCR-mediated calcium mobilization responses. Immature B cells display greater increases ... More
Specific recognition of apoptotic cells reveals a ubiquitous and unconventional innate immunity.
AuthorsCvetanovic M, Mitchell JE, Patel V, Avner BS, Su Y, van der Saag PT, Witte PL, Fiore S, Levine JS, Ucker DS
JournalJ Biol Chem
PubMed ID16707494
'The purpose of physiological cell death is the noninflammatory clearance of cells that have become inappropriate or nonfunctional. Consistent with this function, the recognition of apoptotic cells by professional phagocytes, including macrophages and dendritic cells, triggers a set of potent anti-inflammatory responses manifest on multiple levels. The immediate-early inhibition of ... More
A pivotal role of Rho GTPase in the regulation of morphology and function of dendritic cells.
AuthorsKobayashi M, Azuma E, Ido M, Hirayama M, Jiang Q, Iwamoto S, Kumamoto T, Yamamoto H, Sakurai M, Komada Y
JournalJ Immunol
PubMed ID11564770
'Dendritic cell (DC) is the most potent activator of CD4+ T cells and has unique dendrites and veils. To explore the function of Rho in DC, exoenzyme C3 from Clostridium botulinum was used as a specific inhibitor of Rho. Treatment of DC with C3 (DC/C3) resulted in profound morphological changes ... More
Multiple intracellular pathways for regulation of chloride secretion in cultured pig tracheal submucosal gland cells.
AuthorsZhang AL, Roomans GM
JournalEur Respir J
PubMed ID10232428
'Tracheal submucosal glands are of great relative importance in the secretion of chloride and water to the airway lumen. This study aimed to examine whether the cystic fibrosis transmembrane conductance regulator (CFTR) is involved in cyclic adenosine monophosphate (cAMP) or Ca2+-activated Cl- secretion. Regulation of Cl- secretion in cell cultures ... More
Phosphatidylserine exposure in B lymphocytes: a role for lipid packing.
AuthorsElliott JI, Sardini A, Cooper JC, Alexander DR, Davanture S, Chimini G, Higgins CF,
JournalBlood
PubMed ID16684961
'Plasma membrane lipids are usually distributed asymmetrically, with phosphatidylserine (PS) confined to the inner leaflet. PS exposure at the outer leaflet occurs early in apoptosis, but it is also constitutive on some nonapoptotic cell populations where it plays a role in cell signaling. How PS is transported ("flopped") to the ... More
Induction of neuronal cell death by Rab5A-dependent endocytosis of alpha-synuclein.
AuthorsSung JY, Kim J, Paik SR, Park JH, Ahn YS, Chung KC
JournalJ Biol Chem
PubMed ID11316809
'The presynaptic alpha-synuclein is a prime suspect for contributing to Lewy pathology and clinical aspects of diseases, including Parkinson''s disease, dementia with Lewy bodies, and a Lewy body variant of Alzheimer''s disease. Here we examined the pathogenic mechanism of neuronal cell death induced by alpha-synuclein. The exogenous addition of alpha-synuclein ... More
Ca(2+) regulation of gap junctional coupling in lens epithelial cells.
AuthorsChurchill GC, Lurtz MM, Louis CF
JournalAm J Physiol Cell Physiol
PubMed ID11502574
'The quantitative effects of Ca(2+) signaling on gap junctional coupling in lens epithelial cells have been determined using either the spread of Mn(2+) that is imaged by its ability to quench the fluorescence of fura 2 or the spread of the fluorescent dye Alexa Fluor 594. Gap junctional coupling was ... More
Characterisation of the rat SK4/IK1 K(+) channel.
Authorsvon Hahn T, Thiele I, Zingaro L, Hamm K, Garcia-Alzamora M, Köttgen M, Bleich M, Warth R
JournalCell Physiol Biochem
PubMed ID11509830
'BACKGROUND AND AIMS: The Ca(2+)-activated K(+) channel rSK4 is the rat homologue of the human SK4/IK1 (KCNN4) channel. In colonic mucosa rSK4 plays a key role during acetylcholin-induced secretion. This study was aimed to characterize the properties of the rat SK4 channel. METHODS: Electrophysiological measurements were performed on rSK4 expressing ... More
Spectral imaging fluorescence microscopy.
AuthorsHaraguchi T, Shimi T, Koujin T, Hashiguchi N, Hiraoka Y
JournalGenes Cells
PubMed ID12296819
The spectral resolution of fluorescence microscope images in living cells is achieved by using a confocal laser scanning microscope equipped with grating optics. This capability of temporal and spectral resolution is especially useful for detecting spectral changes of a fluorescent dye; for example, those associated with fluorescence resonance energy transfer ... More
An easy ratiometric compensation for the extracellular Ca2+ indicator-caused fluorescence artifact.
AuthorsKukkonen JP,
JournalAnal Biochem
PubMed ID19376081
Measurement of intracellular Ca(2+) dynamics is one of the most central real-time assays for cellular signaling. Ratiometric methods reduce the need for internal calibration and also effectively compensate for most artifacts when used in imaging. However, ratiometric calculation cannot compensate for extracellularly leaked (and fluorescent) Ca(2+) indicator and will instead ... More
Measurement of free [Ca2+] changes in agonist-sensitive internal stores using compartmentalized fluorescent indicators.
AuthorsHofer AM,
JournalMethods Mol Biol
PubMed ID16422202
This chapter provides a guide for the use of compartmentalized fluorescentdyes to measure free [Ca2+] in the agonist-sensitive internal store of single cells. The basic steps involve incubating cells with the AM-ester derivative of the appropriate dye (resulting in partitioning of the probe in both the cytoplasm and organelles), and ... More
Coupling of the TCR to integrin activation by Slap-130/Fyb.
AuthorsPeterson EJ, Woods ML, Dmowski SA, Derimanov G, Jordan MS, Wu JN, Myung PS, Liu QH, Pribila JT, Freedman BD, Shimizu Y, Koretzky GA
JournalScience
PubMed ID11567141
SLAP-130/Fyb (SLP-76-associated phosphoprotein or Fyn-binding protein; also known as Fyb/Slap) is a hematopoietic-specific adapter, which associates with and modulates function of SH2-containing leukocyte phosphoprotein of 76 kilodaltons (SLP-76). T cells from mice lacking SLAP-130/Fyb show markedly impaired proliferation following CD3 engagement. In addition, the T cell receptor (TCR) in SLAP-130/Fyb ... More
In vivo targeting of organic calcium sensors via genetically selected peptides.
AuthorsMarks KM, Rosinov M, Nolan GP
JournalChem Biol
PubMed ID15123264
A library of constrained peptides that form stable folded structures was screened for aptamers that bind with high affinity to the fluorescent dye Texas red. Two selected clones had binding constants to Texas red of 25 and 80 pM as phage and binding had minimal effects on the fluorescence of ... More
A simple method for quantitative calcium imaging in unperturbed developing neurons.
AuthorsAlbantakis L, Lohmann C,
JournalJ Neurosci Methods
PubMed ID19682493
Calcium imaging has been widely used to address questions of neuronal function and development. To gain deeper insights into the actions of calcium as a second messenger, but also to measure synaptic function, it is necessary to quantify the level of calcium at rest and during calcium transients. While quantification ... More
Clathrin-mediated endocytosis in snake motor terminals is directly facilitated by intracellular Ca2+.
AuthorsTeng H, Wilkinson RS,
JournalJ Physiol
PubMed ID15860527
At the snake neuromuscular junction, low temperature (LT, 5-7 degrees C) blocks clathrin-mediated endocytosis (CME) while exocytosis is largely unaffected. Thus compensatory endocytosis that normally follows transmitter release is inhibited, or 'delayed' until the preparation is warmed to room temperature (RT). This delay was exploited to observe how changes in ... More
Defective mast cell effector functions in mice lacking the CRACM1 pore subunit of store-operated calcium release-activated calcium channels.
AuthorsVig M, DeHaven WI, Bird GS, Billingsley JM, Wang H, Rao PE, Hutchings AB, Jouvin MH, Putney JW, Kinet JP,
JournalNat Immunol
PubMed ID18059270
CRACM1 (also called Orai1) constitutes the pore subunit of store-operated calcium release-activated calcium channels. A point mutation in the gene encoding CRACM1 is associated with severe combined immunodeficiency disease in humans. Here we generated CRACM1-deficient mice in which beta-galactosidase activity 'reported' CRACM1 expression. CRACM1-deficient mice were smaller in size. Mast ... More
STIM1 gates the store-operated calcium channel ORAI1 in vitro.
AuthorsZhou Y, Meraner P, Kwon HT, Machnes D, Oh-hora M, Zimmer J, Huang Y, Stura A, Rao A, Hogan PG,
JournalNat Struct Mol Biol
PubMed ID20037597
Store-operated Ca(2+) entry through the plasma membrane Ca(2+) release-activated Ca(2+) (CRAC) channel in mammalian T cells and mast cells depends on the sensor protein stromal interaction molecule 1 (STIM1) and the channel subunit ORAI1. To study STIM1-ORAI1 signaling in vitro, we have expressed human ORAI1 in a sec6-4 strain of ... More
PINK1-associated Parkinson's disease is caused by neuronal vulnerability to calcium-induced cell death.
AuthorsGandhi S, Wood-Kaczmar A, Yao Z, Plun-Favreau H, Deas E, Klupsch K, Downward J, Latchman DS, Tabrizi SJ, Wood NW, Duchen MR, Abramov AY,
JournalMol Cell
PubMed ID19285945
Mutations in PINK1 cause autosomal recessive Parkinson's disease. PINK1 is a mitochondrial kinase of unknown function. We investigated calcium homeostasis and mitochondrial function in PINK1-deficient mammalian neurons. We demonstrate physiologically that PINK1 regulates calcium efflux from the mitochondria via the mitochondrial Na(+)/Ca(2+) exchanger. PINK1 deficiency causes mitochondrial accumulation of calcium, ... More
New Ca2+ fluoroionophores based on the BODIPY fluorophore.
AuthorsGee KR, Rukavishnikov A, Rothe A
JournalComb Chem High Throughput Screen
PubMed ID12769680
Calcium (Ca(2+)) fluoroionophores are useful in cell-based functional assays of G-protein coupled receptor (GPCR) activation or ion channel modulation. In this paper we describe new calcium probes that improve or overcome certain deficiencies in existing probes. These new fluoroionophores are based on acylation of amino-BAPTA [BAPTA = glycine, N,N'-(1,2-ethanediyl-bis(oxy-2,1-phenylene)) bis(N-(carboxymethyl))] ... More
Proteolytic activity in intact sheets of polarized epithelial cells as determined by a cell-permeable fluorogenic substrate.
AuthorsKarlsson JO, Lundquist J, Skoglund I, Nilsson M
JournalCell Biol Int
PubMed ID10816325
The purpose of the present investigation was to develop a system for continuous evaluation of extralysosomal proteolytic activity and its regulation in polarized epithelial cells. Filter inserts containing a tight monolayer of primary cultured pig thyrocytes were placed in a thermostated aluminium block. The cell-permeable, fluorogenic calpain and proteasome substrate ... More
Mitochondrial pH monitored by a new engineered green fluorescent protein mutant.
AuthorsAbad MF, Di Benedetto G, Magalhães PJ, Filippin L, Pozzan T
JournalJ Biol Chem
PubMed ID14701849
We here describe a new molecularly engineered green fluorescent protein chimera that shows a high sensitivity to pH in the alkaline range. This probe was named mtAlpHi, for mitochondrial alkaline pH indicator, and possesses several key properties that render it optimal for studying the dynamics of mitochondrial matrix pH, e.g. ... More
Deglucuronidation of a flavonoid, luteolin monoglucuronide, during inflammation.
AuthorsShimoi K, Saka N, Nozawa R, Sato M, Amano I, Nakayama T, Kinae N
JournalDrug Metab Dispos
PubMed ID11717168
In this study, we investigated whether luteolin monoglucuronide was converted to free aglycone during inflammation using human neutrophils stimulated with ionomycin/cytochalasin B and rats treated with lipopolysaccharide (LPS). beta-Glucuronidase activity was assayed using 4-methylumbelliferyl-glucuronide and methanol extracts of rat plasma containing luteolin monoglucuronide. The released 4-methylumbelliferone, a fluorescent molecule, was ... More
Crosstalk between cytosolic pH and intracellular calcium in human lymphocytes: effect of 4-aminopyridin, ammoniun chloride and ionomycin.
AuthorsCabado AG, Alfonso A, Vieytes MR, González M, Botana MA, Botana LM
JournalCell Signal
PubMed ID11027951
Stimulation of lymphocytes by specific antigens is followed by the activation of different signal transduction mechanisms, such as alterations in the cytoplasmic levels of Ca(2+), H(+) and variations in membrane potential. To study interrelationships among these parameters, changes in pHi and Ca(2+) were measured with the fluorescent probes BCECF and ... More
Simultaneous in situ monitoring of intracellular Ca2+ and NO in endothelium of coronary arteries.
AuthorsYi FX, Zhang AY, Campbell WB, Zou AP, Van Breemen C, Li PL
JournalAm J Physiol Heart Circ Physiol
PubMed ID12388315
We developed an in situ assay system to simultaneously monitor intracellular Ca(2+) concentration ([Ca(2+)](i), fura 2 as indicator) and nitric oxide (NO) levels [4,5-diaminofluorescein as probe] in the intact endothelium of small bovine coronary arteries by using a fluorescent microscopic imaging technique with high-speed wavelength switching. Bradykinin (BK; 1 microM) ... More
Phospholipase Cdelta4 is required for Ca2+ mobilization essential for acrosome reaction in sperm.
AuthorsFukami K, Yoshida M, Inoue T, Kurokawa M, Fissore RA, Yoshida N, Mikoshiba K, Takenawa T
JournalJ Cell Biol
PubMed ID12695499
Zona pellucida (ZP)-induced acrosome reaction in sperm is a required step for mammalian fertilization. However, the precise mechanism of the acrosome reaction remains unclear. We previously reported that PLCdelta4 is involved in the ZP-induced acrosome reaction in mouse sperm. Here we have monitored Ca2+ responses in single sperm, and we ... More
Simultaneous measurement of multiple active kinase states using polychromatic flow cytometry.
AuthorsPerez OD, Nolan GP
JournalNat Biotechnol
PubMed ID11821861
Intracellular assays of signaling systems have been limited by an inability to correlate functional subsets of cells in complex populations on the basis of active kinase states. Such correlations could be important in distinguishing changes in signaling status that arise in rare cell subsets during functional activation or in disease ... More
Actin polymerization in neutrophils is triggered without a requirement for a rise in cytoplasmic Ca2+.
Authorsal-Mohanna FA, Hallett MB
JournalBiochem J
PubMed ID2158299
Stimulation of rat neutrophils with the peptide fMetLeuPhe caused (i) the appearance of a 40 kDa protein in the Triton-X-100-insoluble cytoskeleton, (ii) the disappearance of DNAase inhibition from the cytosol and (iii) the appearance of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phallacidin (NBD-phallacidin) binding sites. All three observations were consistent with a rapid and transient assembly ... More
A method for the absolute quantification of cDNA using real-time PCR.
AuthorsWhelan JA, Russell NB, Whelan MA
JournalJ Immunol Methods
PubMed ID12957413
Real-time PCR is an extremely powerful technique, however, often its results are open to interpretation since there is no convention for data presentation. This anomaly has arisen because many applications rely on non-standard calibration genes, which themselves often change in value during experimental manipulation. We present a novel method for ... More
Calcium-induced alterations in mitochondrial morphology quantified in situ with optical scatter imaging.
AuthorsBoustany NN, Drezek R, Thakor NV
JournalBiophys J
PubMed ID12202392
Optical scatter imaging (OSI), a technique we developed recently, was used to measure the ratio of wide-to-narrow angle scatter (OSIR) within endothelial cells subjected to calcium overload (1.6 mM) after permeabilization by ionomycin. Within a few minutes of calcium overload, the mitochondria, which started as elongated organelles, rounded up into ... More
Dense core secretory vesicles revealed as a dynamic Ca(2+) store in neuroendocrine cells with a vesicle-associated membrane protein aequorin chimaera.
AuthorsMitchell KJ, Pinton P, Varadi A, Tacchetti C, Ainscow EK, Pozzan T, Rizzuto R, Rutter GA
JournalJ Cell Biol
PubMed ID11571310
The role of dense core secretory vesicles in the control of cytosolic-free Ca(2+) concentrations ([Ca(2+)](c)) in neuronal and neuroendocrine cells is enigmatic. By constructing a vesicle-associated membrane protein 2-synaptobrevin.aequorin chimera, we show that in clonal pancreatic islet beta-cells: (a) increases in [Ca(2+)](c) cause a prompt increase in intravesicular-free Ca(2+) concentration ... More
Calcium regulation of exocytosis in PC12 cells.
AuthorsChen YA, Scales SJ, Duvvuri V, Murthy M, Patel SM, Schulman H, Scheller RH
JournalJ Biol Chem
PubMed ID11359785
The calcium (Ca(2+)) regulation of neurotransmitter release is poorly understood. Here we investigated several aspects of this process in PC12 cells. We first showed that osmotic shock by 1 m sucrose stimulated rapid release of neurotransmitters from intact PC12 cells, indicating that most of the vesicles were docked at the ... More
Sustained calcium entry through P2X nucleotide receptor channels in human airway epithelial cells.
AuthorsZsembery A, Boyce AT, Liang L, Peti-Peterdi J, Bell PD, Schwiebert EM
JournalJ Biol Chem
PubMed ID12566439
Purinergic receptor stimulation has potential therapeutic effects for cystic fibrosis (CF). Thus, we explored roles for P2Y and P2X receptors in stably increasing [Ca(2+)](i) in human CF (IB3-1) and non-CF (16HBE14o(-)) airway epithelial cells. Cytosolic Ca(2+) was measured by fluorospectrometry using the fluorescent dye Fura-2/AM. Expression of P2X receptor (P2XR) ... More
The intraacrosomal calcium pool plays a direct role in acrosomal exocytosis.
AuthorsDe Blas G, Michaut M, Treviño CL, Tomes CN, Yunes R, Darszon A, Mayorga LS
JournalJ Biol Chem
PubMed ID12379648
The acrosome reaction is a unique type of regulated exocytosis. The single secretory granule of the sperm fuses at multiple points with the overlying plasma membrane. In the past few years we have characterized several aspects of this process using streptolysin O-permeabilized human spermatozoa. Here we show that Rab3A triggers ... More
Determination of in situ dissociation constant for Fura-2 and quantitation of background fluorescence in astrocyte cell line U373-MG.
AuthorsPetr MJ, Wurster RD
JournalCell Calcium
PubMed ID9105732
Accurate estimates of cytosolic free Ca2+ with fluorescence indicators are dependent on the determination of the in situ dissociation constants (kd) of the intracellular dyes and the correction for background fluorescence. The in situ dissociation constant for Ca2+ and indicator dye Fura-2/AM varies significantly from the in vitro published values ... More
Inhibition of activated/memory (CD45RO(+)) T cells by oxidative stress associated with block of NF-kappaB activation.
AuthorsMalmberg KJ, Arulampalam V, Ichihara F, Petersson M, Seki K, Andersson T, Lenkei R, Masucci G, Pettersson S, Kiessling R
JournalJ Immunol
PubMed ID11509600
Impaired immune responses in cancer patients have been associated with oxidative stress. Increased levels of reactive oxygen species released from activated, tumor-infiltrating macrophages or granulocytes may therefore constitute a hurdle for effective immunotherapy against cancer. In this study, we investigated functional consequences and molecular events in T cells exposed to ... More
Probing intracellular dynamics in living cells with near-field optics.
AuthorsBui JD, Zelles T, Lou HJ, Gallion VL, Phillips MI, Tan W
JournalJ Neurosci Methods
PubMed ID10476678
Near-field optics (NFO) overcomes the diffraction limit of light microscopes and permits visualization of single molecules. However, despite numerous applications of NFO in the physical sciences, there is still a paucity of applications in the neurosciences. In this work, the authors have developed NFO probes to image intracellular dynamic processes ... More
Ryanodine receptor type I and nicotinic acid adenine dinucleotide phosphate receptors mediate Ca2+ release from insulin-containing vesicles in living pancreatic beta-cells (MIN6).
AuthorsMitchell KJ, Lai FA, Rutter GA
JournalJ Biol Chem
PubMed ID12538591
We have demonstrated recently (Mitchell, K. J., Pinton, P., Varadi, A., Tacchetti, C., Ainscow, E. K., Pozzan, T., Rizzuto, R., and Rutter, G. A. (2001) J. Cell Biol. 155, 41-51) that ryanodine receptors (RyR) are present on insulin-containing secretory vesicles. Here we show that pancreatic islets and derived beta-cell lines ... More
Expression and regulation of calpain in rat pancreatic acinar cells.
AuthorsWeber H, Hopp HH, Wagner AC, Noack T, Jonas L, Lüthen F, Schuff-Werner P
JournalPancreas
PubMed ID11741184
INTRODUCTION: Calpains, cytosolic Ca(2+)-dependent cysteine proteases, are expressed in a variety of mammalian cells and have been found to participate in stimulus-secretion coupling in platelets and alveolar cells. AIMS: In pancreatic acinar cells, expression of calpains and their role in the secretory process have not yet been elucidated. Both subjects, ... More
Mitochondria recycle Ca(2+) to the endoplasmic reticulum and prevent the depletion of neighboring endoplasmic reticulum regions.
AuthorsArnaudeau S, Kelley WL, Walsh JV, Demaurex N
JournalJ Biol Chem
PubMed ID11358971
To study Ca(2+) fluxes between mitochondria and the endoplasmic reticulum (ER), we used "cameleon" indicators targeted to the cytosol, the ER lumen, and the mitochondrial matrix. High affinity mitochondrial probes saturated in approximately 20% of mitochondria during histamine stimulation of HeLa cells, whereas a low affinity probe reported averaged peak ... More
Phospholipases C and A2 control lysosome-mediated IL-1 beta secretion: Implications for inflammatory processes.
AuthorsAndrei C, Margiocco P, Poggi A, Lotti LV, Torrisi MR, Rubartelli A
JournalProc Natl Acad Sci U S A
PubMed ID15192144
Blocking the activity of IL-1 beta has entered the clinical arena of treating autoimmune diseases. However, a successful outcome of this approach requires a clear definition of the mechanisms controlling IL-1 beta release. These are still unclear as IL-1 beta, lacking a secretory signal peptide, follows a nonclassical pathway of ... More
Reciprocal expression of the TNF family receptor herpes virus entry mediator and its ligand LIGHT on activated T cells: LIGHT down-regulates its own receptor.
AuthorsMorel Y, Schiano de Colella JM, Harrop J, Deen KC, Holmes SD, Wattam TA, Khandekar SS, Truneh A, Sweet RW, Gastaut JA, Olive D, Costello RT
JournalJ Immunol
PubMed ID11035077
The TNF receptor (TNFR) family plays a central role in the development of the immune response. Here we describe the reciprocal regulation of the recently identified TNFR superfamily member herpes virus entry mediator (HVEM) (TR2) and its ligand LIGHT (TL4) on T cells following activation and the mechanism of this ... More
Ionomycin, a carboxylic acid ionophore, transports Pb(2+) with high selectivity.
AuthorsErdahl WL, Chapman CJ, Taylor RW, Pfeiffer DR
JournalJ Biol Chem
PubMed ID10702273
Studies utilizing phospholipid vesicle loaded with chelator/indicators for polyvalent cations show that ionomycin transports divalent cations with the selectivity sequence Pb(2+) > Cd(2+) > Zn(2+) > Mn(2+) > Ca(2+) > Cu(2+) > Co(2+) > Ni(2+) > Sr(2+). The selectivity of this ionophore for Pb(2+) is in contrast to that observed ... More
Biomineralization is a highly regulated process that plays a major role during the development of skeletal tissues. Despite its obvious importance, little is known about its regulation. Previously, it has been demonstrated that retinoic acid (RA) stimulates terminal differentiation and mineralization of growth plate chondrocytes (Iwamoto, M., I.M. Shapiro, K. ... More
Regulation of intracellular calcium in human breast cancer cells.
AuthorsSergeev IN, Rhoten WB
JournalEndocrine
PubMed ID10221599
Regulation of intracellular Ca2+ in breast cancer may be important in modulating cell proliferation, differentiation, apoptosis, and cytotoxicity, as well as contributing to mechanisms of action of anticancer agents. One of these agents, the steroid hormone 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], is intimately involved in maintaining cellular Ca2+ homeostasis. The purpose of ... More
Intracellular compartmentalization of fura-2 dye demonstrated by laser-excitation fluorescence microscopy: a problem in measuring cytosolic free calcium concentration using fura-2 fluorescence in vascular smooth muscle cells.
AuthorsTakeuchi K, Sato SI, Abe K, Kimura M, Abe TA, Yoshinaga K, Inaba H
JournalTohoku J Exp Med
PubMed ID2815073
Recently, we have developed a novel laser-excitation fluorescence microscope system to study intracellular calcium (Ca2+) in individual cultured vascular smooth muscle (VSM) cells using fluorescent indicators for (Ca2+). In the course of our study, it was shown that the subcellular fluorescence distribution of fura-2 was not homogeneous in VSM cells ... More
Actions of ionomycin, 4-BrA23187 and a novel electrogenic Ca2+ ionophore on mitochondria in intact cells.
AuthorsAbramov AY, Duchen MR
JournalCell Calcium
PubMed ID12531186
We have used fluorescence digital imaging techniques to explore the actions of two groups of Ca(2+) ionophores: (i). ferutinin, an electrogenic naturally occurring ionophore, and (ii). the neutral ionophores 4-BrA23187 and ionomycin, on cytosolic [Ca(2+)] ([Ca(2+)](c)), mitochondrial [Ca(2+)] ([Ca(2+)](m)) and mitochondrial membrane potential (deltapsi(m)) in HepG2 cells and primary hippocampal ... More
Activated human T lymphocytes exhibit reduced susceptibility to methylmercury chloride-induced apoptosis.
AuthorsClose AH, Guo TL, Shenker BJ
JournalToxicol Sci
PubMed ID10367343
Mercurials have been shown to cause apoptosis in human T cells. The objective of this study was to evaluate and compare the relative susceptibility of resting versus activated T cells to methyl mercury chloride (MeHgCl)-induced cell death. Apoptosis was assessed by Hoechst 33258 and 7-AAD staining and annexin V binding. ... More
Estrogen exerts a spatial and temporal influence on reactive oxygen species generation that precedes calcium uptake in high-capacity mitochondria: implications for rapid nongenomic signaling of cell growth.
AuthorsParkash J, Felty Q, Roy D
JournalBiochemistry
PubMed ID16503642
Novel findings that emerged from this study underscore the fact that the dynamic nature of mitochondria leads to functional heterogeneity of [Ca(2+)](mito) with respect to estrogen actions in MCF7 cells. We show that estrogen exposure to cells increased [Ca(2+)](mito) in a high-calcium capacity mitochondrial population but not in low-calcium capacity ... More
Effect of arachidonic acid reacylation on leukotriene biosynthesis in human neutrophils stimulated with granulocyte-macrophage colony-stimulating factor and formyl-methionyl-leucyl-phenylalanine.
AuthorsZarini S, Gijón MA, Folco G, Murphy RC
JournalJ Biol Chem
PubMed ID16495221
Priming of human neutrophils with granulocyte-macrophage colony-stimulating factor (GM-CSF) followed by treatment with formyl-methionyl-leucyl-phenylalanine (fMLP) stimulates cells in a physiologically relevant manner with modest 5-lipoxygenase activation and formation of leukotrienes. However, pretreatment of neutrophils with thimerosal, an organomercury thiosalicylic acid derivative, led to a dramatic increase (>50-fold) in the production ... More
Measurement of cytoplasmic calcium concentration in the rods of wild-type and transducin knock-out mice.
A 10 microm spot of argon laser light was focused onto the outer segments of intact mouse rods loaded with fluo-3, fluo-4 or fluo-5F, to estimate dark, resting free Ca(2+) concentration ([Ca(2+)](i)) and changes in [Ca(2+)](i) upon illumination. Dye concentration was adjusted to preserve the normal physiology of the rod, ... More
Differential use of myristoyl groups on neuronal calcium sensor proteins as a determinant of spatio-temporal aspects of Ca2+ signal transduction.
Authors O'Callaghan Dermott W; Ivings Lenka; Weiss Jamie L; Ashby Michael C; Tepikin Alexei V; Burgoyne Robert D;
JournalJ Biol Chem
PubMed ID11836243
The localizations of three members of the neuronal calcium sensor (NCS) family were studied in HeLa cells. Using hippocalcin-EYFP and NCS-1-ECFP, it was found that their localization differed dramatically in resting cells. NCS-1 had a distinct predominantly perinuclear localization (similar to trans-Golgi markers), whereas hippocalcin was present diffusely throughout the ... More
Regulation of Ca(2+) signals in a parotid cell line Par-C5.
The Ca(2+) signaling system in an established immortalized rat parotid acinar cell line, Par-C5, was examined using the Ca(2+)-sensitive fluorescent indicator fura-2 and by measuring inositol 1,4,5-trisphosphate (IP(3)) formation. Agonist-induced increase in intracellular Ca(2+) ([Ca(2+)](i)) by mobilization of intracellular stores and influx across the cell membrane was stimulated by acetylcholine ... More
On the sequential determinants of calpain cleavage.
AuthorsTompa P, Buzder-Lantos P, Tantos A, Farkas A, Szilágyi A, Bánóczi Z, Hudecz F, Friedrich P
JournalJ Biol Chem
PubMed ID14988399
The structural clues of substrate recognition by calpain are incompletely understood. In this study, 106 cleavage sites in substrate proteins compiled from the literature have been analyzed to dissect the signal for calpain cleavage and also to enable the design of an ideal calpain substrate and interfere with calpain action ... More
Oncogenic KIT Modulates Type I IFN-Mediated Antitumor Immunity in GIST.
Authors
JournalCancer Immunol Res
PubMed ID33648985
Two-component spike nanoparticle vaccine protects macaques from SARS-CoV-2 infection.
Authors
JournalCell
PubMed ID33577765
TRPA1-FGFR2 binding event is a regulatory oncogenic driver modulated by miRNA-142-3p.
Authors
JournalNat Commun
PubMed ID29038531
T and B cell abnormalities, pneumocystis pneumonia, and chronic lymphocytic leukemia associated with an AIOLOS defect in patients.
Authors
JournalJ Exp Med
PubMed ID34694366
In vitro reconstitution of B cell receptor-antigen interactions to evaluate potential vaccine candidates.
Authors
JournalNat Protoc
PubMed ID26741406
A reverse signaling pathway downstream of Sema4A controls cell migration via Scrib.
Authors
JournalJ Cell Biol
PubMed ID28007914
NOTCH1 is a mechanosensor in adult arteries.
Authors
JournalNat Commun
PubMed ID29158473
Structural and functional properties of a magnesium transporter of the SLC11/NRAMP family.
Authors
JournalElife
PubMed ID35001872
Chanzyme TRPM7 Mediates the Ca2+ Influx Essential for Lipopolysaccharide-Induced Toll-Like Receptor 4 Endocytosis and Macrophage Activation.