Effect of phorbol myristate acetate and the chemotactic peptide fNLPNTL on shape and movement of human neutrophils

1987 ◽  
Vol 88 (3) ◽  
pp. 399-406 ◽  
Author(s):  
F.J. Roos ◽  
A. Zimmermann ◽  
H.U. Keller

The results show that the distinct types of shape produced by phorbol myristate acetate (PMA) and by chemotactic peptides (fNLPNTL) are associated with distinct types of neutrophil movement. Whereas the chemotactic peptide can induce front-tail polarity characterized by an expanding front, a contracted tail and preferential unidirectional movements of intracellular organelles, PMA can only elicit non-polar movements characterized by random formation and retraction of projections all over the surface, intracellular movements of organelles being ill-defined and changing in direction. Combined stimulation of human neutrophils with PMA and fNLPNTL results in a suppression of peptide-induced polarity and the formation of non-polar motile cells resembling those stimulated with PMA alone. The results suggest that the diacylglycerol-protein kinase C pathway may be instrumental in transducing or modulating signals to the locomotor apparatus of the cell. PMA-treated cells are, however, still capable of developing directional responses when appropriately stimulated. The findings lead to the hypothesis that distinct types of neutrophil movements are preferentially associated with distinct functions.

Blood ◽  
1981 ◽  
Vol 58 (1) ◽  
pp. 129-134 ◽  
Author(s):  
D English ◽  
JS Roloff ◽  
JN Lukens

Abstract Human neutrophils exposed to chemotactic concentrations of zymosan- activated serum (ZAS) and a formylated chemotactic peptide (FMLP, 10(- 7)--10(-9) M) were markedly enhanced in their ability to generate superoxide (O2-) upon stimulation with either sodium fluoride or phorbol myristate acetate (PMA). For both fluoride and PMA, enhancement was characterized by a decrease in the lag from stimulation to initiation of superoxide release and by an increase in the rate of superoxide generation--representing faster activation and increased activity of O2- generating enzyme, respectively. Chemotactic concentrations of casein, normal serum, and casein-treated serum enhanced the activity, but not the rate of activation, of the fluoride- stimulated superoxide generating system. This effect on activity was not so impressive as that obtained with FMLP or ZAS. The mechanisms by which FMLP enhanced responsiveness to fluoride and PMA were found to be different. Optimal enhancement for fluoride-stimulated responses required extracellular Ca++. Extracellular glucose, but not extracellular Ca++, was required for enhancement of FMLP of PMA- stimulated responses. A similar glucose requirement could not be demonstrated for chemotactic peptide enhancement of the superoxide- generating system stimulated by fluoride. Fluoride and PMA apparently activate the neutrophil O2- generating enzyme by pathways that are not identical. However, responsiveness of the enzyme to both agents is susceptible to modulation by cellular responses to chemotactic peptides.


Blood ◽  
1981 ◽  
Vol 58 (1) ◽  
pp. 129-134 ◽  
Author(s):  
D English ◽  
JS Roloff ◽  
JN Lukens

Human neutrophils exposed to chemotactic concentrations of zymosan- activated serum (ZAS) and a formylated chemotactic peptide (FMLP, 10(- 7)--10(-9) M) were markedly enhanced in their ability to generate superoxide (O2-) upon stimulation with either sodium fluoride or phorbol myristate acetate (PMA). For both fluoride and PMA, enhancement was characterized by a decrease in the lag from stimulation to initiation of superoxide release and by an increase in the rate of superoxide generation--representing faster activation and increased activity of O2- generating enzyme, respectively. Chemotactic concentrations of casein, normal serum, and casein-treated serum enhanced the activity, but not the rate of activation, of the fluoride- stimulated superoxide generating system. This effect on activity was not so impressive as that obtained with FMLP or ZAS. The mechanisms by which FMLP enhanced responsiveness to fluoride and PMA were found to be different. Optimal enhancement for fluoride-stimulated responses required extracellular Ca++. Extracellular glucose, but not extracellular Ca++, was required for enhancement of FMLP of PMA- stimulated responses. A similar glucose requirement could not be demonstrated for chemotactic peptide enhancement of the superoxide- generating system stimulated by fluoride. Fluoride and PMA apparently activate the neutrophil O2- generating enzyme by pathways that are not identical. However, responsiveness of the enzyme to both agents is susceptible to modulation by cellular responses to chemotactic peptides.


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.


1993 ◽  
Vol 106 (2) ◽  
pp. 493-501
Author(s):  
A. Volz

The study analyses the distribution and quantitative expression of surface CD18 of neutrophils exposed to distinct stimuli that produce different types of continuous shape changes, including types that are associated with locomotion and others that are not. The chemotactic peptide N-formyl-L-norleucyl-L-leucyl-L-phenylalanine, colchicine and nocodazole were used to induce a polarized locomotor morphology, phorbol myristate acetate, 1,2-dioctanoylglycerol and 1-oleoyl-2-acetyl-glycerol to induce non-polar motile cells ruffling all over the surface and 2H2O to induce non-polar cells performing circus movements as have been previously described. Except for colchicine and nocodazole, these stimuli increased surface expression of CD18. Thus, stimulated shape changes are frequently, though not always, associated with increased surface expression of CD18. High concentrations (10(−7) to 10(−5) M) of phorbol myristate acetate but not of chemotactic peptide induced down-regulation of surface CD18. Cytochalasin D (10(−4) M) stimulated CD18 expression even though it inhibited shape changes. The surface distribution of CD18 determined by light microscopy was uniform in unstimulated cells or in various forms of stimulation except for cells treated with 10(−5) M cytochalasin D. Cytochalasin D (10(−5) M) produced CD18 accumulation at the pole opposite the F-actin cap. Experiments with colchicine, nocodazole, 2H2O and cytochalasin D suggest that microtubules as well as microfilaments modulate surface expression of CD18. The results suggest that protein kinase C and phosphatases play a role in regulating surface expression of CD18 in neutrophils.(ABSTRACT TRUNCATED AT 250 WORDS)


1993 ◽  
Vol 265 (5) ◽  
pp. G955-G962 ◽  
Author(s):  
W. F. Stenson ◽  
R. A. Easom ◽  
T. E. Riehl ◽  
J. Turk

Caco-2 cells are an enterocyte-like cell line derived from a human colonic adenocarcinoma. Paracellular permeability was assessed in monolayers of these cells by transmonolayer resistance and by the permeation of [3H]mannitol across the monolayer. Paracellular permeability was increased by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (50 nM), carbachol (500 microM), and the combination of carbachol (50 microM) and monolein (100 microM), an inhibitor of diacylglycerol kinase, as manifested by a decrease in transmonolayer resistance and an increase in mannitol permeation. The effects of all of these stimuli on transmonolayer resistance were inhibited by staurosporine (3 nM), an inhibitor of PKC. The effects of carbachol plus monolein were also inhibited by atropine (0.1 microM), a muscarinic antagonist. Treatment of the monolayers with each of the stimuli was associated with translocation of PKC activity from cytosol to a membrane-associated state. Stimulation of Caco-2 cell monolayers with phorbol myristate acetate or with the combination of carbachol and monolein was also associated with phosphorylation of the MARCKS protein, an endogenous substrate of PKC. These data support the hypothesis that intestinal paracellular permeability is regulated by the activity of enterocyte PKC and demonstrate that the increase in paracellular permeability induced by binding of carbachol to the muscarinic receptor is mediated by activation of PKC.


1986 ◽  
Vol 64 (8) ◽  
pp. 1149-1152 ◽  
Author(s):  
Kenneth Wong ◽  
Christine Chew

Cellular responses induced in human neutrophils by the synthetic diacylglycerol, 1-oleoyl-2-acetyl-glycerol (OAG), paralleled those induced by phorbol myristate acetate (PMA). Like PMA, OAG caused the preferential release of enzymes from specific granules and promoted superoxide (O2−) generation. The efficacy of OAG was similar to that for PMA, but its potency was lower by four orders of magnitude. First derivative kinetic analysis showed that rates of O2− generation elicited by PMA decayed exponentially in a first order manner; the half life was found to be 21 ± 6 min. Results obtained in studies carried out with high OAG concentrations were similar except that after 40 min, the rate of decay increased and became complex order. This difference was attributed to the greater susceptibility of OAG to metabolic alteration, and was reflected in the NADPH oxidase activity of granule rich membrane fractions (GRF) of cells stimulated for 90 min with PMA or OAG. It was found that the O2− generating activity of the PMA treated GRF was significantly greater than that for the OAG treated fraction. Current evidence indicates that cellular responses arise from direct activation of protein kinase C by PMA-OAG. The stability of this complex and the bypassing of normal regulatory constraints may account for the relative longevity of the PMA–OAG O2− respiratory burst.


1989 ◽  
Vol 264 (3) ◽  
pp. 879-884 ◽  
Author(s):  
B Dewald ◽  
M Thelen ◽  
M P Wymann ◽  
M Baggiolini

The protein kinase C inhibitor staurosporine influenced in different ways the functions of human neutrophils. Staurosporine prevented the enhanced protein phosphorylation in phorbol ester- and N-formylmethyionyl-leucylphenylalanine (fMLP)-stimulated cells, and was a powerful inhibitor of the respiratory burst induced by phorbol myristate acetate [IC50 (concentration causing 50% inhibition) 17 nM] and the chemotactic peptides fMLP and C5a (IC50 24 nM). It did not alter, however, the superoxide production by cell-free preparations of NADPH oxidase. Staurosporine had no effect on agonist-dependent changes in cytosolic free Ca2+ and exocytosis of specific and azurophil granules, and showed only a slight inhibition of the release of vitamin B12-binding protein induced by phorbol myristate acetate (decreased by 40% at 200 nM). On the other hand, staurosporine also exhibited neutrophil-activating properties: it induced the release of gelatinase (from secretory vesicles) and vitamin-B12-binding protein (from specific granules). These effects were protracted, concentration-dependent, insensitive to Ca2+ depletion, and strongly enhanced by cytochalasin B. Staurosporine, however, did not induce the release of beta-glucuronidase or elastase (from azurophil granules). Except for the sensitivity to cytochalasin B, these properties suggest a similarity between the exocytosis-inducing actions of staurosporine and PMA. The results obtained with staurosporine provide further evidence that different signal-transduction processes are involved in neutrophil activation, and suggest that protein phosphorylation is required for the induction of the respiratory burst, but not for exocytosis.


Sign in / Sign up

Export Citation Format

Share Document