scholarly journals Activation of human neutrophils by mastoparan. Reorganization of the cytoskeleton, formation of phosphatidylinositol 3,4,5-trisphosphate, secretion up-regulation of complement receptor type 3 and superoxide anion production are stimulated by mastoparan

1992 ◽  
Vol 282 (2) ◽  
pp. 393-397 ◽  
Author(s):  
J Norgauer ◽  
M Eberle ◽  
H D Lemke ◽  
K Aktories

In human neutrophils, mastoparan induced rapid F-actin polymerization which was followed by a slow and sustained depolymerization to below the initial F-actin content. Incubation of neutrophils with pertussis toxin inhibited mastoparan-stimulated actin polymerization; however it did not prevent sustained depolymerization of F-actin. Analyses of phospholipids performed in parallel revealed that mastoparan stimulated rapid formation of phosphatidylinositol 3,4,5-trisphosphate (PIP3) and consumption of phosphatidylinositol 4,5-bisphosphate (PIP2). Pertussis toxin treatment blocked mastoparan-induced formation of PIP3. Furthermore, mastoparan stimulated the release of N-acetylglucosaminidase from primary granules. Cytochalasin B enhanced mastoparan-stimulated secretion. Mastoparan triggered superoxide radical production in a cytochalasin B-sensitive manner and induced complement type 3 receptor (CR3) up-regulation.

1986 ◽  
Vol 237 (2) ◽  
pp. 601-604 ◽  
Author(s):  
S W Edwards ◽  
T F Swan

The role of myeloperoxidase in the regulation of the respiratory burst of human neutrophils activated by the chemotactic peptide (N-formyl-L-methionyl-L-leucyl-L-phenylalanine) plus cytochalasin B was determined by using anti-(human myeloperoxidase) antibody. The respiratory burst activated under these conditions consisted of an initial (1-2 min) phase with high rates of O2 uptake, luminol-dependent chemiluminescence and superoxide radical (O2-.) generation and a second, more sustained, phase of lower magnitude of chemiluminescence and O2 uptake: O2-. generation did not occur during this second phase. In cell suspensions stimulated in the presence of anti-(human myeloperoxidase) antibody, the magnitude of the initial phase of both O2 uptake and O2-. generation was unaffected, but these high rates were maintained over much longer periods than in control suspensions. It is therefore proposed that a product of myeloperoxidase normally regulates the duration of O2-. generation during the respiratory burst, possibly by inhibition of NADPH oxidase.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2286 ◽  
Author(s):  
Chuan-Yen Wei ◽  
Shih-Wei Wang ◽  
Jin-Wang Ye ◽  
Tsong-Long Hwang ◽  
Ming-Jen Cheng ◽  
...  

A new aporphine, 3-hydroxyhernandonine (1) and a new lignin, 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), have been isolated from the root wood of Hernanadia nymphaeifolia, together with thirteen known compounds (3–15). The structures of these compounds were determined through mass spectrometry (MS) and spectroscopic analyses. The known isolate, 2-O-methyl-7-oxolaetine (3), was first isolated from natural sources. Among the isolated compounds, 3-hydroxyhernandonine (1), 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), hernandonine (4), oxohernangerine (5), and oxohernagine (6) displayed inhibition (IC50 values ≤5.72 μg/mL) of superoxide anion production by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). In addition, 3-hydroxyhernandonine (1), 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), oxohernangerine (5), and oxohernagine (6) suppressed fMLP/CB-induced elastase release with IC50 values ≤5.40 μg/mL.


2009 ◽  
Vol 102 (8) ◽  
pp. 1125-1135 ◽  
Author(s):  
Alberto Dávalos ◽  
Gema de la Peña ◽  
Carolina C. Sánchez-Martín ◽  
M. Teresa Guerra ◽  
Begoña Bartolomé ◽  
...  

The NADPH oxidase enzyme system is the main source of superoxide anions in phagocytic and vascular cells. NADPH oxidase-dependent superoxide generation has been found to be abnormally enhanced in several chronic diseases. Evidence is accumulating that polyphenols may have the potential to improve cardiovascular health, although the mechanism is not fully established. Consumption of concentrated red grape juice, rich in polyphenols, has been recently shown to reduce NADPH oxidase activity in circulating neutrophils from human subjects. In the present work we studied whether red grape juice polyphenols affected NADPH oxidase subunit expression at the transcription level. For this, we used human neutrophils and mononuclear cells from peripheral blood, HL-60-derived neutrophils and the endothelial cell line EA.hy926.Superoxide production was measured with 2′7′-dichlorofluorescein diacetate or lucigenin, mRNA expression by real-time RT-PCR and protein expression by Western blot. Each experiment was performed at least three times. In all cell types tested, red grape juice, dealcoholised red wine and pure polyphenols decreased superoxide anion production. Red grape juice and dealcoholised red wine selectively reduced p47phox, p22phox and gp91phox expression at both mRNA and protein levels, without affecting the expression of p67phox. Pure polyphenols, particularly quercetin, also reduced NADPH oxidase subunit expression, especially p47phox, in all cell types tested. The present results showing that red grape juice polyphenols reduce superoxide anion production provide an alternative mechanism by which consumption of grape derivatives may account for a reduction of oxidative stress associated with cardiovascular and/or inflammatory diseases related to NADPH oxidase superoxide overproduction.


1994 ◽  
Vol 102 (3) ◽  
pp. 310-314 ◽  
Author(s):  
Johannes Norgauer ◽  
Jean Krutmann ◽  
Gustav J. Dobos ◽  
Alexis E. Traynor-Kaplan ◽  
Zenaida G. Oades ◽  
...  

1990 ◽  
Vol 96 (1) ◽  
pp. 99-106
Author(s):  
H.U. Keller ◽  
V. Niggli ◽  
A. Zimmermann ◽  
R. Portmann

The present study demonstrates new properties of H-7. The protein kinase inhibitor H-7 is a potent activator of several neutrophil functions. Stimulation of initially spherical nonmotile neutrophils elicits vigorous shape changes within a few seconds, increases in cytoskeletal actin, altered F-actin distribution, increased adhesiveness and a relatively small increase in pinocytic activity. H-7 has also chemokinetic activities. Depending on the experimental condition, H-7 may elicit or inhibit neutrophil locomotion. It failed to induce chemotaxis. Thus, the response pattern elicited by H-7 is different from that of other leukocyte activators such as chemotactic peptides, PMA or diacylglycerols. The finding that H-7 can elicit shape changes, actin polymerization and pinocytosis suggests that these events can occur without activation of protein kinase C (PKC). PMA-induced shape changes and stimulation of pinocytosis were not inhibited by H-7.


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