Studies on the mechanisms of autophagy: maturation of the autophagic vacuole.
AuthorsDunn WA
JournalJ Cell Biol
PubMed ID2161853
'Data presented in the accompanying paper suggests nascent autophagic vacuoles are formed from RER (Dunn, W. A. 1990. J. Cell Biol. 110:1923-1933). In the present report, the maturation of newly formed or nascent autophagic vacuoles into degradative vacuoles was examined using morphological and biochemical methods combined with immunological probes. Within ... More
Monitoring autophagy in Alzheimer's disease and related neurodegenerative diseases.
AuthorsYang DS, Lee JH, Nixon RA,
JournalMethods Enzymol
PubMed ID19216904
'This chapter describes detailed methods to monitor autophagy in neurodegenerative disorders, especially in Alzheimer''s disease. Strategies to assess the competence of autophagy-related mechanisms in disease states ideally incorporate analyses of human disease and control tissues, which may include brain, fibroblasts, or other peripheral cells, in addition to animal and cell ... More
Impaired class II expression and antigen uptake in monocytic cells after HIV-1 infection.
AuthorsPolyak S, Chen H, Hirsch D, George I, Hershberg R, Sperber K
JournalJ Immunol
PubMed ID9278305
'Using the human macrophage hybridoma cell line 43 and primary monocytes, we investigated the regulation of class II expression and intracellular Ag trafficking after HIV-1 infection. The HIV-1-infected human macrophage hybridoma cell line, 43HIV, lost class II Ag expression, as determined by immunofluorescence, immunoprecipitation, and Northern blot analysis, 2 wk ... More
Retrograde transport from the pre-Golgi intermediate compartment and the Golgi complex is affected by the vacuolar H+-ATPase inhibitor bafilomycin A1.
AuthorsPalokangas H, Ying M, Väänänen K, Saraste J
JournalMol Biol Cell
PubMed ID9843588
'The effect of the vacuolar H+-ATPase inhibitor bafilomycin A1 (Baf A1) on the localization of pre-Golgi intermediate compartment (IC) and Golgi marker proteins was used to study the role of acidification in the function of early secretory compartments. Baf A1 inhibited both brefeldin A- and nocodazole-induced retrograde transport of Golgi ... More
Vesicles and cisternae in the trans Golgi apparatus of human fibroblasts are acidic compartments.
AuthorsAnderson RG, Pathak RK
JournalCell
PubMed ID3882239
'Recently we demonstrated that low-pH compartments can be visualized with the electron microscope using a basic congener of dinitrophenol, 3-(2,4-dinitroanilino)-3''-amino-N-methyldipropylamine (DAMP), which concentrates in acidic compartments and can be detected by immunocytochemistry with a monoclonal anti-dinitrophenol antibody. We now report that DAMP also accumulates in cisternae and vesicles associated with ... More
Immunology and the confocal microscope.
AuthorsOjcius DM, Niedergang F, Subtil A, Hellio R, Dautry-Varsat A
JournalRes Immunol
PubMed ID8817746
'The techniques of classical epifluorescence microscopy are already widely used by the immunological community to detect antigens at the cellular level. Coupled with the use of specific inhibitors that affect diverse intracellular events, these techniques have provided valuable information on the mechanisms involved in antigen presentation. The same biological samples ... More
Defective acidification of intracellular organelles in cystic fibrosis.
AuthorsBarasch J, Kiss B, Prince A, Saiman L, Gruenert D, al-Awqati Q
JournalNature
PubMed ID1712081
'The phenotype of cystic fibrosis (CF) includes abnormalities in transepithelial transport of Cl- (refs 1-5), decreased sialylation and increased sulphation and fucosylation of glycoproteins, and lung colonization with Pseudomonas. It is not apparent how these abnormalities are interrelated, nor how they result from loss of function of the CF gene-encoded ... More
Visualization of acidic compartments in cultured osteoclasts by use of an acidotrophic amine as a marker for low pH.
AuthorsInoue M, Yoshida H, Akisaka T
JournalCell Tissue Res
PubMed ID10639743
'Using the acidotrophic amine 3-(2,4-dinitroanillino)-3'-amino-N-methyldipropylamine (DAMP) as a marker for low pH and immunofluorescence cytochemistry, we examined acidic compartments of osteoclasts cultured on cover glasses or bone slices, where they could resorb the bone surface, forming resorptive lacunae. DAMP-positive structures were seen as vesicular and tubular forms in the cytoplasm, ... More
A view of acidic intracellular compartments.
AuthorsAnderson RG, Orci L
JournalJ Cell Biol
PubMed ID3279044
Chloride channels of intracellular organelles.
Authorsal-Awqati Q
JournalCurr Opin Cell Biol
PubMed ID7495569
Chloride channels are present in a variety of intracellular organelles (Golgi, endosomes, endoplasmic reticulum, and sarcoplasmic reticulum) where they serve largely to shunt the membrane potential created by other ion-translocating processes. Electrophysiological studies have shown that the Cl- channels of the endoplasmic and sarcoplasmic reticula facilitate the efflux of Ca2+. ... More
Experiments on the use of DAMP to study retina and cultured neurons.
AuthorsAugenbraun E, Sulzer D, Rayport S, Setlik W, Holtzman E
JournalJ Histochem Cytochem
PubMed ID1701464
Immunocytochemical localization of DAMP, a reagent used to detect low pH intracellular compartments, was studied in cultured neurons from rat hippocampus and in frog retinas. We find that DAMP is more sharply localized and that the immunocytochemical reaction is stronger when horseradish peroxidase or other proteins are included in the ... More
Functional dissociation of the basolateral transcytotic compartment from the apical phago-lysosomal compartment in human osteoclasts.
AuthorsMeagher J, Zellweger R, Filgueira L,
JournalJ Histochem Cytochem
PubMed ID15872059
Tartrate-resistant acid phosphatase (TRAP) is essential for elimination of Staphylococcus aureus, the main infectious agent responsible for osteomyelitis. This in vitro study investigated uptake and processing of fluorescence-labeled S. aureus by human osteoclasts and dendritic cells. The cells were stained for TRAP and the acidic compartment using a fluorescence-based protocol. ... More
pH-independent and -dependent cleavage of proinsulin in the same secretory vesicle.
AuthorsOrci L, Halban P, Perrelet A, Amherdt M, Ravazzola M, Anderson RG
JournalJ Cell Biol
PubMed ID8063854
By quantitative immunoelectron microscopy and HPLC, we have studied the effect of disrupting pH gradients, by ammonium chloride, on proinsulin conversion in the insulin-producing B-cells of the islets of langerhans. Proinsulin content and pH in single secretory vesicles were measured on consecutive serial sections immunostained alternately with anti-proinsulin or anti-dinitrophenol ... More
In situ detection of starvation-induced autophagy.
AuthorsMartinet W, De Meyer GR, Andries L, Herman AG, Kockx MM,
JournalJ Histochem Cytochem
PubMed ID16148314
Autophagy is a regulated bulk degradation process involved in many different human pathologies. Transmission electron microscopy (TEM) is currently the only reliable method for monitoring autophagy in situ. Because TEM is labor intensive, we questioned whether useful marker proteins can be found for unambiguous detection of autophagy in tissue via ... More
Early intracellular events during internalization of Listeria monocytogenes by J774 cells.
AuthorsWebster P
JournalJ Histochem Cytochem
PubMed ID11897803
The gram-positive bacillus Listeria monocytogenes gains entry into host cells through a phagosome membrane that forms around entering bacteria. During the early stages of internalization the invading bacteria appear to modify the protein composition of the forming phagosome membrane in J774 cells. MHC class II molecules on the cell surface ... More
Tamoxifen inhibits acidification in cells independent of the estrogen receptor.
AuthorsAltan N, Chen Y, Schindler M, Simon SM
JournalProc Natl Acad Sci U S A
PubMed ID10200279
Tamoxifen has been reported to have numerous physiological effects that are independent of the estrogen receptor, including sensitization of resistant tumor cells to many chemotherapeutic agents. Drug-resistant cells sequester weak base chemotherapeutics in acidic organelles away from their sites of action in the cytosol and nucleus. This work reports that ... More
The mannose 6-phosphate receptor and the biogenesis of lysosomes.
AuthorsGriffiths G, Hoflack B, Simons K, Mellman I, Kornfeld S
JournalCell
PubMed ID2964276
Localization of the 215 kd mannose 6-phosphate receptor (MPR) was studied in normal rat kidney cells. Low levels of receptor were detected in the trans Golgi network, Golgi stack, plasma membrane, and peripheral endosomes. The bulk of the receptor was localized to an acidic, reticular-vesicular structure adjacent to the Golgi ... More
Quantitative four-dimensional tracking of cytoplasmic and nuclear HIV-1 complexes.
AuthorsArhel N, Genovesio A, Kim KA, Miko S, Perret E, Olivo-Marin JC, Shorte S, Charneau P
JournalNat Methods
PubMed ID16990814
Emerging real-time techniques for imaging viral infections provide powerful tools for understanding the dynamics of virus-host cell interactions. Here we labeled human immunodeficiency virus-1 (HIV-1) integrase with a small tetracysteine tag, which preserved the virus' infectivity while allowing it to be labeled with the bis-arsenical fluorescein derivative FlAsH. This labeling ... More
Internalization of Chlamydia by dendritic cells and stimulation of Chlamydia-specific T cells.
AuthorsOjcius DM, Bravo de Alba Y, Kanellopoulos JM, Hawkins RA, Kelly KA, Rank RG, Dautry-Varsat A
JournalJ Immunol
PubMed ID9570547
Chlamydia species are the causative agents of trachoma, various forms of pneumonia, and the most common sexually transmitted diseases. Although the infection cycle has been extensively characterized in epithelial cells, where the Chlamydia entry-vacuoles avoid fusion with host-cell lysosomes, the cellular immune response has received less attention. Moreover, despite the ... More
Internalized plasma membrane cholesterol passes through an endosome compartment that is distinct from the acid vesicle-lysosome compartment.
AuthorsPorpaczy Z, Tomasek JJ, Freeman DA
JournalExp Cell Res
PubMed ID9260888
Cholesterol from the plasma membrane of MA-10 Leydig tumor cells is internalized into the cell and either esterified or used as substrate for steroid hormone synthesis. In the present studies we show that chloroquine and sphinganine cause LDL cholesterol and cholesteryl esters to accumulate in the cells. A lysosome fraction ... More
Partial characterization of cytoplasmic compartments involved in the endocytic process of Tritrichomonas foetus.
AuthorsAffonso AL, de Almeida JC, Benchimol M
JournalEur J Cell Biol
PubMed ID9084987
The endocytic pathway of Tritrichomonas foetus, a parasitic protozoan of cattle, was studied using (a) vital dyes, such as Lucifer yellow, neutral red and acridine orange, (b) cationized ferritin, (c) gold-labeled lactoferrin and lectins: HPA, UEA, PNA and LPA, and (d) DAMP (3-(2,4-dinitroanilino) 3' amino-N-methyldipropylamine). Light and confocal laser microscopy ... More
Regulation of pH by the M2 protein of influenza A viruses.
AuthorsCiampor F, Thompson CA, Grambas S, Hay AJ
JournalVirus Res
PubMed ID1626420
Inhibition of the function of the M2 protein by amantadine can cause a conformational change in the haemagglutinin (HA) of H7 influenza A viruses and the consequent expression of the low pH form of the glycoprotein on the surface of virus-infected cells. Immunofluorescence studies showed that this conversion occurs shortly ... More
Distinct protein sorting and localization to premelanosomes, melanosomes, and lysosomes in pigmented melanocytic cells.
AuthorsRaposo G, Tenza D, Murphy DM, Berson JF, Marks MS
JournalJ Cell Biol
PubMed ID11266471
Melanosomes and premelanosomes are lysosome-related organelles with a unique structure and cohort of resident proteins. We have positioned these organelles relative to endosomes and lysosomes in pigmented melanoma cells and melanocytes. Melanosome resident proteins Pmel17 and TRP1 localized to separate vesicular structures that were distinct from those enriched in lysosomal ... More
Visualization of acidic organelles in intact cells by electron microscopy.
AuthorsAnderson RG, Falck JR, Goldstein JL, Brown MS
JournalProc Natl Acad Sci U S A
PubMed ID6146980
We report the synthesis of a probe that permits the visualization by electron microscopy of acidic organelles in intact cells. This probe, 3-(2,4-dinitroanilino)-3'-amino-N-methyldipropylamine (DAMP), is a basic congener of dinitrophenol that readily diffuses into intact cells. Its primary and tertiary amino groups (apparent pKa, 10.6) allow it to be concentrated ... More
Cloning of ACP33 as a novel intracellular ligand of CD4.
AuthorsZeitlmann L, Sirim P, Kremmer E, Kolanus W
JournalJ Biol Chem
PubMed ID11113139
CD4 recruitment to T cell receptor (TCR)-peptide-major histocompatibility class II complexes is required for stabilization of low affinity antigen recognition by T lymphocytes. The cytoplasmic portion of CD4 is thought to amplify TCR-initiated signal transduction via its association with the protein tyrosine kinase p56(lck). Here we describe a novel functional ... More
Internalization of microbubbles by tumor cells in vivo and in vitro.
AuthorsBarbarese E, Ho SY, D'Arrigo JS, Simon RH
JournalJ Neurooncol
PubMed ID8583242
Lipid-coated microbubbles (LCM) administered intravenously (i.v.) to rats bearing brain tumor, specifically enhance tumor visualization by ultrasound [1]. In order to understand the basis for this observation, we have examined the interactions of LCM with glioblastoma (C6) and gliosarcoma (9L) tumor cells in vivo and in vitro. LCM and LCM ... More
Disturbed cholesterol traffic but normal proteolytic function in LAMP-1/LAMP-2 double-deficient fibroblasts.
AuthorsEskelinen EL, Schmidt CK, Neu S, Willenborg M, Fuertes G, Salvador N, Tanaka Y, Lüllmann-Rauch R, Hartmann D, Heeren J, von Figura K, Knecht E, Saftig P
JournalMol Biol Cell
PubMed ID15121881
Mice double deficient in LAMP-1 and -2 were generated. The embryos died between embryonic days 14.5 and 16.5. An accumulation of autophagic vacuoles was detected in many tissues including endothelial cells and Schwann cells. Fibroblast cell lines derived from the double-deficient embryos accumulated autophagic vacuoles and the autophagy protein LC3II ... More
Mechanisms of pH regulation in the regulated secretory pathway.
AuthorsWu MM, Grabe M, Adams S, Tsien RY, Moore HP, Machen TE
JournalJ Biol Chem
PubMed ID11402049
A precise pH gradient between organelles of the regulated secretory pathway is required for sorting and processing of prohormones. We studied pH regulation in live endocrine cells by targeting biotin-based pH indicators to cellular organelles expressing avidin-chimera proteins. In AtT-20 cells, we found that steady-state pH decreased from the endoplasmic ... More
Distinct endosomal compartments in early trafficking of low density lipoprotein-derived cholesterol.
AuthorsSugii S, Reid PC, Ohgami N, Du H, Chang TY
JournalJ Biol Chem
PubMed ID12721287
We previously studied the early trafficking of low density lipoprotein (LDL)-derived cholesterol in mutant Chinese hamster ovary cells defective in Niemann-Pick type C1 (NPC1) using cyclodextrin (CD) to monitor the arrival of cholesterol from the cell interior to the plasma membrane (PM) (Cruz, J. C., Sugii, S., Yu, C., and ... More
Conversion of proinsulin to insulin occurs coordinately with acidification of maturing secretory vesicles.
AuthorsOrci L, Ravazzola M, Amherdt M, Madsen O, Perrelet A, Vassalli JD, Anderson RG
JournalJ Cell Biol
PubMed ID3536964
Proinsulin is a single polypeptide chain composed of the B and A subunits of insulin joined by the C-peptide region. Proinsulin is converted to insulin during the maturation of secretory vesicles by the action of two proteases and conversion is inhibited by ionophores that disrupted intracellular H+ gradients. To determine ... More
Active vacuolar H+ATPase is required for both endocytic and exocytic processes during viral infection of BHK-21 cells.
AuthorsPalokangas H, Metsikkö K, Väänänen K
JournalJ Biol Chem
PubMed ID8021266
Bafilomycin A1 (Baf), a specific inhibitor of the vacuolar-type proton pump, inhibited the entry of Semliki Forest virus and vesicular stomatitis virus into BHK-21 cells. The inhibition occurred at concentrations that dissipated intracellular acidic compartments. Viral infection was totally inhibited by 30 nM Baf while endocytosis of the virus or ... More
Intracellular routes and selective retention of antigens in mildly acidic cathepsin D/lysosome-associated membrane protein-1/MHC class II-positive vesicles in immature dendritic cells.
Immature dendritic cells (DC) use both macropinocytosis and mannose receptor-mediated endocytosis to internalize soluble Ags efficiently. These Ags are ultimately presented to T cells after DC maturation and migration into the lymph nodes. We have previously described the immortalized myeloid cell line FSDC as displaying the characteristics of early DC ... More
Ehrlichia chaffeensis inclusions are early endosomes which selectively accumulate transferrin receptor.
AuthorsBarnewall RE, Rikihisa Y, Lee EH
JournalInfect Immun
PubMed ID9119487
Ehrlichia chaffeensis is an obligatory intracellular bacterium which infects macrophages and monocytes. Double immunofluorescence labeling was used to characterize the nature of E. chaffeensis inclusion in the human promyelocytic leukemia cell line THP-1. E. chaffeensis was labeled with dog anti-E. chaffeensis serum and fluorescein isothiocyanate-conjugated anti-dog immunoglobulin G (IgG). Lissamine ... More
Hyaluronan enters keratinocytes by a novel endocytic route for catabolism.
AuthorsTammi R, Rilla K, Pienimaki JP, MacCallum DK, Hogg M, Luukkonen M, Hascall VC, Tammi M
JournalJ Biol Chem
PubMed ID11451952
Hyaluronan synthesized in the epidermis has an exceptionally short half-life, indicative of its catabolism by epidermal keratinocytes. An intracellular pool of endogenously synthesized hyaluronan, from 1 to 20 fg/cell, inversely related to cell density, was observed in cultured rat epidermal keratinocytes. More than 80% of the intracellular hyaluronan was small ... More
Antigen trafficking and accessory cell function in respiratory epithelial cells.
AuthorsSalik E, Tyorkin M, Mohan S, George I, Becker K, Oei E, Kalb T, Sperber K
JournalAm J Respir Cell Mol Biol
PubMed ID10460754
We investigated accessory cell function, antigen (Ag) trafficking, and uptake of immune complexes in isolated nasal epithelial cells (NEC) and airway epithelial cells (AEC), as well as in the two respiratory epithelial cell lines A549 and BEAS-2B. The NEC and AEC were capable of supporting Ag-specific as well as phytohemagglutinin-induced ... More
Immunocytochemistry of calciosomes in liver and pancreas.
Calciosomes are small cytoplasmic vacuoles identified in various nonmuscle cell types by their content of protein(s) similar to calsequestrin (CS), the Ca2+ storage protein of the muscle sarcoplasmic reticulum (SR). These entities have been interpreted as the "primitive" counterpart of the SR, and suggested to be the organelle target of ... More
Differential localization and functional role of calsequestrin in growing and differentiated myoblasts.
AuthorsRaichman M, Panzeri MC, Clementi E, Papazafiri P, Eckley M, Clegg DO, Villa A, Meldolesi J
JournalJ Cell Biol
PubMed ID7844148
Calsequestrin (CSQ) is the low affinity, high capacity Ca(2+)-binding protein concentrated within specialized areas of the muscle fiber sarcoplasmic reticulum (a part of the ER) where it is believed to buffer large amounts of Ca2+. Upon activation of intracellular channels this Ca2+ pool is released, giving rise to the [Ca2+]i ... More
Proteolysis of the major yolk glycoproteins is regulated by acidification of the yolk platelets in sea urchin embryos.
The precise function of the yolk platelets of sea urchin embryos during early development is unknown. We have shown previously that the chemical composition of the yolk platelets remains unchanged in terms of phospholipid, triglyceride, hexose, sialic acid, RNA, and total protein content after fertilization and early development. However, the ... More
In exocrine pancreas, the basolateral endocytic pathway converges with the autophagic pathway immediately after the early endosome.
AuthorsTooze J, Hollinshead M, Ludwig T, Howell K, Hoflack B, Kern H
JournalJ Cell Biol
PubMed ID2166050
Intracisternal granules (ICGs) are insoluble aggregates of pancreatic digestive enzymes and proenzymes that develop within the lumen of the rough endoplasmic reticulum of exocrine pancreatic cells, especially in guinea pigs. These ICGs are eliminated by autophagy. By morphological criteria, we identified three distinct and sequential classes of autophagic compartments, which ... More
Deficient peptide loading and MHC class II endosomal sorting in a human genetic immunodeficiency disease: the Chediak-Higashi syndrome.
AuthorsFaigle W, Raposo G, Tenza D, Pinet V, Vogt AB, Kropshofer H, Fischer A, de Saint-Basile G, Amigorena S
JournalJ Cell Biol
PubMed ID9606205
The Chediak-Higashi syndrome (CHS) is a human recessive autosomal disease caused by mutations in a single gene encoding a protein of unknown function, called lysosomal-trafficking regulator. All cells in CHS patients bear enlarged lysosomes. In addition, T- and natural killer cell cytotoxicity is defective in these patients, causing severe immunodeficiencies. ... More
Regulation of class II expression in monocytic cells after HIV-1 infection.
AuthorsRakoff-Nahoum S, Chen H, Kraus T, George I, Oei E, Tyorkin M, Salik E, Beuria P, Sperber K
JournalJ Immunol
PubMed ID11490022
Human macrophage hybridoma cells were used to study HLA-DR expression after HIV-1 infection. HLA-DR surface expression was lost 2 wk after infection that was associated with decreased mRNA transcription. Transfecting HLA-DR-alpha and HLA-DR-beta cDNA driven by a nonphysiological CMV promoter restored expression, suggesting that regulatory DNA-binding proteins may be affected ... More
Dynamic measurement of the pH of the Golgi complex in living cells using retrograde transport of the verotoxin receptor.
AuthorsKim JH, Lingwood CA, Williams DB, Furuya W, Manolson MF, Grinstein S
JournalJ Cell Biol
PubMed ID8830769
The B subunit of verotoxin (VT1B) from enterohemorrhagic Escherichia coli is responsible for the attachment of the holotoxin to the cell surface, by binding to the glycolipid, globotriaosyl ceramide. After receptor-mediated endocytosis, the toxin is targeted to the Golgi complex by a process of retrograde transport. We took advantage of ... More
Acquisition of Lubrol insolubility, a common step for growth hormone and prolactin in the secretory pathway of neuroendocrine cells.
AuthorsLee MS, Zhu YL, Chang JE, Dannies PS
JournalJ Biol Chem
PubMed ID11024038
Rat prolactin in the dense cores of secretory granules of the pituitary gland is a Lubrol-insoluble aggregate. In GH(4)C(1) cells, newly synthesized rat prolactin and growth hormone were soluble, but after 30 min about 40% converted to a Lubrol-insoluble form. Transport from the endoplasmic reticulum is necessary for conversion to ... More
Concanamycin A, a powerful tool for characterization and estimation of contribution of perforin- and Fas-based lytic pathways in cell-mediated cytotoxicity.
AuthorsKataoka T, Shinohara N, Takayama H, Takaku K, Kondo S, Yonehara S, Nagai K
JournalJ Immunol
PubMed ID8621902
Perforin- and Fas-based cytolytic pathways are two major mechanisms of cell-mediated cytotoxicity. Recently, we have shown that an inhibitor of vacuolar type H+-ATPase, concanamycin A (CMA), inhibits perforin-based cytotoxic activity, mostly due to accelerated degradation of perforin by an increase in the pH of lytic granules. Here we show that ... More
Overexpression of calsequestrin in L6 myoblasts: formation of endoplasmic reticulum subdomains and their evolution into discrete vacuoles where aggregates of the protein are specifically accumulated.
AuthorsGatti G, Podini P, Meldolesi J
JournalMol Biol Cell
PubMed ID9307974
Calsequestrin (CSQ), the major low-affinity Ca(2+)-binding glycoprotein of striated muscle fibers, is concentrated to yield aggregates that occupy the lumen of the terminal cisternae of the sarcoplasmic reticulum (SR). When infected or transfected into L6 myoblast, the protein is also concentrated, however, in dense vacuoles apparently separate from the endoplasmic ... More
ATP-mediated killing of Mycobacterium bovis bacille Calmette-Guérin within human macrophages is calcium dependent and associated with the acidification of mycobacteria-containing phagosomes.
AuthorsStober CB, Lammas DA, Li CM, Kumararatne DS, Lightman SL, McArdle CA
JournalJ Immunol
PubMed ID11342651
We previously demonstrated that extracellular ATP stimulated macrophage death and mycobacterial killing within Mycobacterium bovis Bacille Calmette-Guérin (BCG)-infected human macrophages. ATP increases the cytosolic Ca(2+) concentration in macrophages by mobilizing intracellular Ca(2+) via G protein-coupled P2Y receptors, or promoting the influx of extracellular Ca(2+) via P2X purinoceptors. The relative contribution ... More
Modified lysosomal compartment as carrier of slowly and non-degradable tracers in macrophages.
AuthorsTassin MT, Lang T, Antoine JC, Hellio R, Ryter A
JournalEur J Cell Biol
PubMed ID2081525
A previous immunocytochemical study of macrophages infected with Bacillus subtilis showed that a cell wall antigen could be detected for several days in a population of small vesicles randomly distributed within the cells and apparently distinct from perinuclear lysosomes. These observations suggested the possibility that these vesicles might constitute a ... More
Thyrotropin induces the acidification of the secretory granules of parafollicular cells by increasing the chloride conductance of the granular membrane.
Secretory granules of sheep thyroid parafollicular cells contain serotonin, a serotonin-binding protein, and calcitonin. Parafollicular cells, isolated by affinity chromatography, were found to secrete serotonin when activated by thyrotropin (TSH) or elevated [Ca2+]e. TSH also induced a rise in [Ca2+]i. We studied the effect of these secretogogues on the pH ... More
Association of tissue factor pathway inhibitor with human umbilical vein endothelial cells.
AuthorsHansen JB, Olsen R, Webster P
JournalBlood
PubMed ID9345040
Tissue factor pathway inhibitor (TFPI) is a serine protease inhibitor of the extrinsic coagulation system, synthesized in endothelial cells, which has recently been shown to play an important role in the regulation of activated coagulation factors at the endothelial cell surface. In the present study we investigated the subcellular localization ... More