scholarly journals Role of microtubule assembly in lysosomal enzyme secretion from human polymorphonuclear leukocytes. A reevaluation.

1977 ◽  
Vol 73 (1) ◽  
pp. 242-256 ◽  
Author(s):  
S Hoffstein ◽  
I M Goldstein ◽  
G Weissmann
Keyword(s):  
Plasma Membrane ◽  
Dose Response ◽  
Lysosomal Enzyme ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Microtubule Assembly ◽  
Enzyme Release ◽  
Thin Sections ◽  
Human Polymorphonuclear Leukocytes ◽  
In Cells

The dose-related inhibition by colchicine of both lysosomal enzyme release and microtubule assembly was studied in human polymorphonuclear leukocytes (PMN) exposed to the nonphagocytic stimulus, zymosan-treated serum (ZTS). Cells were pretreated with colchicine (60 min, 37 degrees C) with or without cytochalasin B (5 microng/ml, 10 min) and then stimulated with ZTS (10%). Microtubule numbers in both cytochalasin B-treated and untreated PMN were increased by stimulation and depressed below resting levels in a dose-response fashion by colchicine concentrations above 10(-7) M. These concentrations also inhibited enzyme release in a dose-response fashion although the inhibition of microtubule assembly was proportionately greater than the inhibition of enzyme release. Other aspects of PMN morphology were affected by colchicine. Cytochalasin B-treated PMN were rounded, and in thin sections the retracted plasma membrane appeared as invaginations oriented toward centrally located centrioles. Membrane invaginations were restricted to the cell periphery in cells treated with inhibitory concentrations of colchicine, and the centrioles and Golgi apparatus were displaced from their usual position. After stimulation and subsequent degranulation, the size and number of membrane invaginations greatly increased. They remained peripheral in cells pretreated with greater than 10(-7) M colchicine but were numerous in the pericentriolar region in cells treated with less than 10(-7) M. Similarly, untreated PMN that were permitted to phagocytose immune precipitates had many phagosomes adjacent to the centriole. After colchicine treatment, phagosomes were distributed randomly, without any preferential association with the centrioles. These data suggest that microtubules are involved in maintaining the internal organization of cells and the topologic relationships between organelles and the plasma membrane.

scholarly journals Mechanisms of lysosomal enzyme release from human polymorphonuclear leukocytes. Effects of phorbol myristate acetate.

1975 ◽  
Vol 66 (3) ◽  
pp. 647-652 ◽  
Author(s):  
I M Goldstein ◽  
S T Hoffstein ◽  
G Weissmann
Keyword(s):  
Phorbol Myristate Acetate ◽  
Lysosomal Enzyme ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Enzyme Release ◽  
Myristate Acetate ◽  
Azurophil Granule ◽  
Cytoplasmic Microtubules ◽  
Specific Granule ◽  
Human Polymorphonuclear Leukocytes

PMA enhanced release of the azurophil granule enzyme, beta-glucuronidase, as well as lysozyme, from cytochalasin B-treated PMN's exposed to either zymosan particles or C5a. PMA was active at nanomolar concentrations, was not toxic to the cells, and was most effective when present for brief durations (0-1 min) before exposure of the cells to the stimuli. Beta-glucuronidase was not released in significant amounts from PMN's exposed to PMA alone, in the absence of stimuli such as zymosan or C5a. In contrast, only the specific granule enzyme, lysozyme, was released from unstimulated cells. Electron micrographs of cells exposed to PMA revealed an increase in the number of visible cytoplasmic microtubules as compared to control cells. Enhancement of lysosomal enzyme (beta-glucuronidase) release by PMA appears to be independent of effects on release of specific granule enzymes (lysozyme), but rather is likely due to PMA-induced elevations of cellular cGMP.

scholarly journals Pertussis toxin inhibition of chemotactic factor-induced calcium mobilization and function in human polymorphonuclear leukocytes.

1985 ◽  
Vol 162 (1) ◽  
pp. 145-156 ◽  
Author(s):  
D W Goldman ◽  
F H Chang ◽  
L A Gifford ◽  
E J Goetzl ◽  
H R Bourne
Keyword(s):  
Pertussis Toxin ◽  
Lysosomal Enzyme ◽  
Polymorphonuclear Leukocytes ◽  
Regulatory Protein ◽  
Leukotriene B4 ◽  
Ionophore A23187 ◽  
Enzyme Release ◽  
Adp Ribosylation ◽  
Chemotactic Factors ◽  
Human Polymorphonuclear Leukocytes

Chemotactic factors stimulate a rapid increase in the cytosolic concentration of intracellular calcium ions ([Ca2+]in) in human polymorphonuclear leukocytes (PMNL), which may be an event that is critical to the expression of chemotaxis and other PMNL functions. Treatment of PMNL with pertussis toxin catalyzes ADP-ribosylation of a protein similar or identical to the inhibiting regulatory protein of adenylate cyclase, Gi, and suppresses the increase in [Ca2+]in elicited by leukotriene B4(LTB4) and formyl-methionyl-leucyl-phenylalanine. Chemotactic migration and lysosomal enzyme release elicited by chemotactic factors were inhibited by pertussis toxin with a concentration-dependence similar to that for inhibition of the increase in [Ca2+]in, without an effect on lysosomal enzyme release induced by the ionophore A23187 and phorbol myristate acetate. Activated pertussis toxin catalyzed the [32P]ADP-ribosylation of a 41 kD protein in homogenates of PMNL. The extent of [32P]ADP-ribosylation of this protein was reduced 59% by pretreatment of intact PMNL with pertussis toxin. Pertussis toxin selectively decreased the number of high-affinity receptors for LTB4 on PMNL by 60% without altering the number or binding properties of the low-affinity subset of receptors. Pertussis toxin modification of a membrane protein of PMNL analogous to Gi thus simultaneously alters chemotactic receptors and attenuates the changes in cytosolic calcium concentration and PMNL function caused by chemotactic factors.

scholarly journals Changes in ionic movements across rabbit polymorphonuclear leukocyte membranes during lysosomal enzyme release. Possible ionic basis for lysosomal enzyme release.

1977 ◽  
Vol 75 (3) ◽  
pp. 635-649 ◽  
Author(s):  
P H Naccache ◽  
H J Showell ◽  
E L Becker ◽  
R I Sha'afi
Keyword(s):  
Lysosomal Enzyme ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Calcium Influx ◽  
Flow Diagram ◽  
Ionophore A23187 ◽  
Enzyme Release ◽  
45Ca Efflux ◽  
Ionic Movements ◽  
Ionic Basis

Changes in the movements of Na+, K+, and Ca+2 across rabbit neutrophils under conditions of lysosomal enzyme release have been studied. We have found that in the presence of cytochalasin B, the chemotactic factor formyl methionyl leucyl phenylalanine (FMLP) induces within 30 s large enhancements in the influxes of both 22Na+ and 45Ca+2 and an increase in the cellular pool of exchangeable calcium. The magnitude of the changes induced by cytochalasin B and FMLP exceeds that induced by FMLP or cytochalasin B alone, and cannot be explained on the basis of an additive effect of the two agents. However, these compounds either separately or together produce much smaller enhancements in 45Ca efflux. The divalent cation ionophore A23187 also produces a rapid and large increase in the influxes of both 22Na and 45Ca+2 in the presence and absence of cytochalasin B. We have also found an excellent correlation between calcium influx and lysosomal enzyme release. 42K influx is not significantly affected by any of these compounds. On the other hand, a large and rapid increase of 42K efflux is observed under conditions which give rise to lysosomal enzyme release. A flow diagram of the events that are thought to accompany the stimulation of polymorphonuclear leukocytes (PMNs) by chemotactic or degranulating stimuli is presented.

scholarly journals Functional activity of enucleated human polymorphonuclear leukocytes.

1983 ◽  
Vol 97 (2) ◽  
pp. 368-377 ◽  
Author(s):  
D Roos ◽  
A A Voetman ◽  
L J Meerhof
Keyword(s):  
Plasma Membrane ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Unit Area ◽  
Chemotactic Activity ◽  
Myristate Acetate ◽  
Intact Cells ◽  
Ficoll Gradient ◽  
Pmn Functions ◽  
Human Polymorphonuclear Leukocytes

Enucleated human polymorphonuclear leukocytes (PMN) were prepared by centrifuging isolated, intact PMN over a discontinuous Ficoll gradient that contained 20 microM cytochalasin B. The enucleated cells (PMN cytoplasts) contained about one-third of the plasma membrane and about one-half of the cytoplasm present in intact PMN. The PMN cytoplasts contained no nucleus and hardly any granules. The volume of the PMN cytoplasts was about one-fourth of that of the original PMN. Greater than 90% of the PMN cytoplasts had an "outside-out" topography of the plasma membrane. Cytoplasts prepared from resting PMN did not generate superoxide radicals (O2-) or hydrogen peroxide. PMN cytoplasts incubated with opsonized zymosan particles or phorbol-myristate acetate induced a respiratory burst that was qualitatively (O2 consumption, O2- and H2O2 generation) and quantitatively (per unit area of plasma membrane) comparable with that of intact, stimulated PMN. Moreover, at low ratios of bacteria/cells, PMN cytoplasts ingested opsonized Staphylococcus aureus bacteria as well as did intact PMN. At higher ratios, the cytoplasts phagocytosed less well. The killing of these bacteria by PMN cytoplasts was slower than by intact cells. The chemotactic activity of PMN cytoplasts was very low. These results indicate that the PMN apparatus for phagocytosis, generation of bactericidal oxygen compounds, and killing of bacteria, as well as the mechanism for recognizing opsonins and activating PMN functions, are present in the plasma membrane and cytosol of these cells.

scholarly journals Microtubule dynamics and glutathione metabolism in phagocytizing human polymorphonuclear leukocytes.

1978 ◽  
Vol 76 (2) ◽  
pp. 439-447 ◽  
Author(s):  
B R Burchill ◽  
J M Oliver ◽  
C B Pearson ◽  
E D Leinbach ◽  
R D Berlin
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Reduced Glutathione ◽  
Human Peripheral Blood ◽  
Microtubule Assembly ◽  
Glutathione Metabolism ◽  
Resting Cells ◽  
Tertiary Butyl ◽  
Thin Sections ◽  
Butyl Hydroperoxide ◽  
Human Polymorphonuclear Leukocytes

Glutathione oxidants such as tertiary butyl hydroperoxide were shown previously to prevent microtubule assembly and cause breakdown of preassembled cytoplasmic microtubules in human polymorphonuclear leukocytes. The objectives of the present study were to determine the temporal relationship between the attachment and ingestion of phagocytic particles and the assembly of microtubules, and simultaneously to quantify the levels of reduced glutathione and products of its oxidation as potential physiological regulators of assembly. Polymorphonuclear leukocytes from human peripheral blood were induced to phagocytize opsonized zymosan at 30 degrees C. Microtubule assembly was assessed in the electron microscope by direct counts of microtubules in thin sections through centrioles. Acid extracts were assayed for reduced glutathione (GSH) and oxidized glutathione (GSSG), by the sensitive enzymatic procedure of Tietze. Washed protein pellets were assayed for free sulfhydryl groups and for mixed protein disulfides with glutathione (protein-SSG) after borohydride splitting of the disulfide bond. Resting cells have few assembled microtubules. Phagocytosis induces a cycle of rapid assembly followed by disassembly. Assembly is initiated by particle contact and is maximal by 3 min of phagocytosis. Disassembly after 5-9 min of phagocytosis is preceded by a slow rise in GSSG and coincides with a rapid rise in protein-SSG. Protein-SSG also increases under conditions in which butyl hydroperoxide inhibits the assembly of microtubules that normally follows binding of concanavalin A to leukocyte cell surface receptors. No evidence for direct involvement of GSH in the induction of assembly was obtained. The formation of protein-SSG, however, emerges as a possible regulatory mechanism for the inhibition of microtubule assembly and induction of their disassembly.

scholarly journals INHIBITION OF PHAGOCYTOSIS AND PLASMA MEMBRANE MOBILITY OF THE CULTIVATED MACROPHAGE BY CYTOCHALASIN B

1974 ◽  
Vol 62 (3) ◽  
pp. 647-659 ◽  
Author(s):  
Stanton G. Axline ◽  
Eve P. Reaven
Keyword(s):  
Plasma Membrane ◽  
Dose Response ◽  
Cell Shape ◽  
Cytochalasin B ◽  
Drug Effects ◽  
Hexose Transport ◽  
Response Curves ◽  
Uptake Inhibition ◽  
Thin Sections ◽  
Additional Support

Functional and morphologic effects of cytochalasin B on the cultivated macrophage were examined to determine the basis for plasma membrane movements of the type required for endocytosis and/or spreading on a substratum. Inhibition of phagocytosis and changes in cell shape by cytochalasin B exhibited nearly identical dose-response curves requiring 2–5 x 10-6 M and 1–2 x 10-5 M cytochalasin B to inhibit these functions by 50% and 100%, respectively. In contrast, hexose transport was ten times more sensitive to the drug requiring 2–3 x 10-7 M cytochalasin B to achieve 50% inhibition of 2-deoxyglucose uptake. Inhibition of phagocytosis and changes in cell shape could not be explained solely by drug effects on hexose transport. Analysis of serial thin sections showed that cytochalasin B doses inhibitory for hexose transport had no effect on distribution or organization of either of the two subplasmalemmal microfilament types. However, cytochalasin B concentrations (2.0 x 10-5 M) that inhibited phagocytosis and altered cell shape disorganized and/or disrupted oriented bundles of 40–50-Å subplasmalemmal microfilaments, but had no effect on the microfilamentous network. Comparative dose-response studies showing positive correlations among cytochalasin B effects on phagocytosis, changes in cell shape, and alterations in oriented subplasmalemmal microfilament bundles provide additional support for the hypothesis that microfilamentous structures play a role in translocation of plasma membrane required for endocytosis and cell motility.

scholarly journals Concanavalin A induces microtubule assembly and specific granule discharge in human polymorphonuclear leukocytes.

1976 ◽  
Vol 68 (3) ◽  
pp. 781-787 ◽  
Author(s):  
S Hoffstein ◽  
R Soberman ◽  
I Goldstein ◽  
G Weissmann
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Microtubule Assembly ◽  
Human Neutrophils ◽  
Con A ◽  
Specific Granules ◽  
Specific Granule ◽  
Human Polymorphonuclear Leukocytes

Human neutrophils stimulated by concanavalin A (Con A, 100 microng/ml) contained markedly enhanced numbers of microtubules and discharged peroxidase-negative (specific) but not peroxidase-position (azurophile) granules. Release of lysozyme from specific granules was dose and time dependent, could be inhibitied by alpha-methyl-D-mannoside, and enhanced by cytochalasin B. Many microtubules were associated with internalized plasma membrane bearing Con A binding sites.

scholarly journals Microfilaments and microtubules in calcium ionophore-induced secretion of lysosomal enzymes from human polymorphonuclear leukocytes.

1978 ◽  
Vol 78 (3) ◽  
pp. 769-781 ◽  
Author(s):  
S Hoffstein ◽  
G Weissmann
Keyword(s):  
Plasma Membrane ◽  
Lysosomal Enzymes ◽  
Cytochalasin B ◽  
Human Peripheral Blood ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Microtubule Assembly ◽  
Ionophore A23187 ◽  
Enzyme Release ◽  
Experimental Conditions

Human peripheral blood leukocytes (PMN) are induced to release lysosomal enzymes by the calcium ionophore A23187 in the presence but not the absence of extracellular Ca++. Whereas secretion induced by particulate or immune stimuli is accompanied by an increase in visible microtubules and is inhibitable by colchicine, secretion induced by A23187 and Ca++ was not accompanied by an increase in microtubule numbers and was not inhibited by colchicine. Ca++ did not appear to regulate microtubule assembly in these cells since resting PMN had a mean of 22.3 +/- 2.0 microtubules in the centriolar region as compared to 22.3 +/- 1.1 in ionophore-treated cells and 24.9 +/- 1.5 in cells exposed to ionophore and 1 mM Ca++. Bipolar filaments, 10 nm thick and 300--400 nm long, were numerous in the pericortical cytoplasm of cells exposed to both reagents. Microtubules in these cells were decorated with an electron-opaque fibrillar material. PMN exposed to A23187 and Ca++ were contracted in two directions at right angles to each other: (a) Contractions parallel to the plasma membrane resulted in extensive plication of the cell membrane. The cytoplasm subjacent to the plicae contained dense filamentous webs. Plication was prevented by cytochalasin B or reversed by subsequent exposure to an endocytic stimulus such as zymosan. (b) Contractions perpendicular to the plasma membrane, toward the cytocenter, resulted in the formation of vacuoles in normal PMN and of membrane invaginations in cytochalasin B-treated PMN. Whereas contractions parallel to the plasma membrane could occur in the absence of enzyme release (ionophore alone) and enzyme release could occur in the absence of such contractions (ionophore plus calcium plus cytochalasin B), contraction toward the cytocenter occurred in all experimental conditions in which significant enzyme release was obtained. Thus, lysosomal enzyme secretion in PMN involves contractile movements in the plasma membrane toward the lysosomes rather than the reverse. These calcium-mediated contractile events are mediated by cytochalasin B-insensitive microfilaments but not by microtubule assembly.

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