scholarly journals Mechanism of thrombin-induced rise in platelet fructose 2,6-bisphosphate content. Studies using phorbol myristate acetate, dioctanoylglycerol and ionophore A23187

1987 ◽  
Vol 244 (3) ◽  
pp. 547-551 ◽  
Author(s):  
V Vasta ◽  
P Bruni ◽  
M Farnararo
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Myristate Acetate ◽  
Ionophore A23187 ◽  
Myristate Acetate ◽  
Kinase C ◽  
Protein Kinase C Activation

The mechanism by which thrombin increases platelet fructose 2,6-bisphosphate content was investigated. The action of thrombin was mimicked by phorbol 12 myristate 13-acetate and 1,2-dioctanoylglycerol. Ca2+ with A23187 potentiated the action of both these compounds. The action of thrombin required mobilization of intracellular and extracellular Ca2+ and was not decreased by indomethacin. This study suggests that protein kinase C activation and Ca2+ mobilization are both involved in the activation of glycolysis by thrombin.

Comparison of the modes of action of Ca2+ ionophore A23187 and thrombin in protein kinase C activation in human platelets

FEBS Letters ◽  
1985 ◽  
Vol 192 (1) ◽  
pp. 4-8 ◽  
Author(s):  
Kimihiko Sano ◽  
Hajime Nakamura ◽  
Tamotsu Matsuo ◽  
Yasuhiro Kawahara ◽  
Hisashi Fukuzaki ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Modes Of Action ◽  
Kinase C ◽  
Protein Kinase C Activation

Regulation of paracellular permeability in Caco-2 cell monolayers by protein kinase C

1993 ◽  
Vol 265 (5) ◽  
pp. G955-G962 ◽  
Author(s):  
W. F. Stenson ◽  
R. A. Easom ◽  
T. E. Riehl ◽  
J. Turk
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Myristate Acetate ◽  
Paracellular Permeability ◽  
Colonic Adenocarcinoma ◽  
Myristate Acetate ◽  
Cell Monolayers ◽  
Kinase C ◽  
Endogenous Substrate ◽  
Stimulation Of

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.

Involvement of protein kinase C in macrophage activation by poly(I.C)

1994 ◽  
Vol 266 (1) ◽  
pp. C134-C142 ◽  
Author(s):  
F. R. Lake ◽  
E. C. Dempsey ◽  
J. D. Spahn ◽  
D. W. Riches
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Myristate Acetate ◽  
Mrna Levels ◽  
Myristate Acetate ◽  
Western Blots ◽  
Level Of Involvement ◽  
Polycytidylic Acid ◽  
Kinase C ◽  
Polyinosinic Polycytidylic Acid

The expression of cytocidal activity is initiated by the interaction of macrophages with priming [e.g., interferon (IFN)] and triggering stimuli (polyinosinic-polycytidylic acid). We have shown that the triggering step can be initiated in a Ca(2+)-dependent fashion and hypothesized that protein kinase C (PKC) may couple the Ca2+ signal to the expression of a gene product, Bf, that accompanies the expression of macrophage cytocidal activity. Exposure of IFN-primed macrophages to polyinosinic-polycytidylic acid in the presence of the PKC inhibitors H-7 or sphingosine or after downregulation of PKC with phorbol myristate acetate markedly inhibited Bf synthesis. Western blots of macrophage lysates revealed the presence of the alpha-, delta-, and zeta-isozymes of PKC, and all were found to be downregulated by phorbol myristate acetate. Inhibition of PKC also prevented the increase in IFN-beta mRNA levels and partially blocked the response to IFN-beta. These data suggest that the alpha-, delta-, and zeta-isozymes of PKC are involved in signaling leading to Bf expression and that the level of involvement is restricted to the induction and response to IFN-beta.

Tetanus toxin attenuates the ability of phorbol myristate acetate to mobilize cytosolic protein kinase C in NG-108 cells

Toxicon ◽  
1990 ◽  
Vol 28 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Robert V. Considine ◽  
John K. Bielicki ◽  
Lance L. Simpson ◽  
Joseph R. Sherwin
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Myristate Acetate ◽  
Tetanus Toxin ◽  
Myristate Acetate ◽  
Cytosolic Protein ◽  
Kinase C

Contrasting effects of inflammatory stimuli on neutrophil and monocyte adherence to endothelial cells

1989 ◽  
Vol 67 (2) ◽  
pp. 556-562 ◽  
Author(s):  
D. W. Kamp ◽  
K. D. Bauer ◽  
A. Knap ◽  
M. M. Dunn
Keyword(s):  
Hydrogen Peroxide ◽  
Endothelial Cells ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Myristate Acetate ◽  
Superoxide Anion ◽  
Leukocyte Adherence ◽  
Myristate Acetate ◽  
Kinase C ◽  
Monocyte Adherence

Leukocyte adherence to endothelial cells (EC) is an important early event in inflammatory responses, which are often characterized by a predominance of either neutrophils (PMN) or monocytes. However, there is little information concerning the molecular events important in leukocyte adherence to EC. Intracellular activation of protein kinase C and the calcium-second messenger system leads to the stimulation of a number of important functions in PMN and monocytes. We compared the effects of members of these pathways on human PMN and monocyte adherence to cultured bovine aortic EC. We observed that phorbol myristate acetate, phorbol, 12,13-dibutyrate, L-alpha-1-oleoyl-2-acetoyl-sn-3-glycerol, and ionomycin each induced significant dose-dependent increases in PMN adherence to EC monolayers. In contrast, similar concentrations of each of these agents induced significant decreases in EC adherence of monocytes enriched by countercurrent centrifugal elutriation. Separate experiments determined that the differences in PMN and monocyte adherence to EC were not related to differences in oxidant production because 1) phorbol myristate acetate and L-alpha-1-oleoyl-2-acetoyl-sn-3-glycerol caused similar marked increases in both PMN and monocyte superoxide anion and hydrogen peroxide production and 2) ionomycin, which had opposing effects on PMN and monocyte adherence, had no effect on PMN and monocyte superoxide anion or hydrogen peroxide release. We conclude that activators of protein kinase C and the Ca-second messenger pathway have opposite effects on PMN and monocyte adherence to EC and that these effects are mediated by O2 radical-independent mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Involvement of the Ca2+-dependent phosphorylation of a 20 kDa protein in the proliferative effect of high-density lipoproteins (subclass 3) on the adenocarcinoma cell line A549

1995 ◽  
Vol 307 (2) ◽  
pp. 557-561 ◽  
Author(s):  
K A Tazi ◽  
M Bonnafous ◽  
G Favre ◽  
G Soula ◽  
F Le Gaillard
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Ester ◽  
Phorbol Myristate Acetate ◽  
High Density Lipoproteins ◽  
Myristate Acetate ◽  
Adenocarcinoma Cell Line ◽  
Adenocarcinoma Cell ◽  
Proliferative Effect ◽  
Kinase C

Previous studies from our laboratory demonstrated that high-density lipoproteins (subclass 3; HDL3) bind to sites specific for apolipoprotein AI on the human adenocarcinoma cell line A549 and that HDL3 binding promotes a mitogenic effect [Favre, Tazi, Le Gaillard, Bennis, Hachem and Soula (1993) J. Lipid Res. 34, 1093-1106]. In the present study, we have examined the cell proteins that showed modified phosphorylation after binding of HDL3 to specific sites, and the roles of Ca2+ and protein kinase C. Native HDL3 (but not tetranitromethane-modified HDL3) and Ca2+ ionophore A23187 strongly enhanced the phosphorylation of a 20 kDa protein (x 3.6) and, to a lower extent, the phosphorylation of 24 and 28 kDa proteins (x 2.2 and 2.6 respectively). The two effectors were equally able to stimulate cell growth. Down-regulation of protein kinase C by a 24 h incubation of cells with phorbol myristate acetate prevented the effects of HDL3 on the phosphorylation of 24 and 28 kDa proteins. However, the extent of phosphorylation of the 20 kDa protein was not affected. In contrast, activation of protein kinase C by a short incubation with phorbol myristate acetate resulted in inhibition of proliferation and an increase in 24 and 28 kDa (but not 20 kDa) protein phosphorylation. These results suggest that HDL3 putative receptors exert their proliferative effect on A549 cells through activation of a Ca(2+)-dependent protein kinase. This kinase activity is not modulated by phorbol ester and thus may be a calmodulin kinase or an isoenzyme of protein kinase C that is independent of phorbol ester. It allows a subsequent 20 kDa protein to be phosphorylated.

scholarly journals Destabilization of natriuretic peptide C-receptor mRNA by phorbol myristate acetate.

1998 ◽  
Vol 9 (1) ◽  
pp. 26-32
Author(s):  
R V Paul ◽  
P S Wackym ◽  
M N Budisavljevic
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Natriuretic Peptide ◽  
Phorbol Myristate Acetate ◽  
Actinomycin D ◽  
Mesangial Cells ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Myristate Acetate ◽  
Kinase C

Natriuretic peptide C receptor (NPR-C) expression in rat mesangial cells is downregulated by platelet-derived growth factor (PDGF) and the protein kinase C agonist phorbol myristate acetate (PMA). This study shows that PDGF and PMA diminish NPR-C mRNA abundance and that PMA does so by accelerating the degradation of the transcript. Exposure to PMA (0.1 microM) decreased mesangial cell NPR-C mRNA levels by more than 50% within 3 h and 125I-atrial natriuretic peptide binding by approximately 50% within 6 h. Disappearance of NPR-C transcripts after PMA treatment was more than twice as rapid as that seen after inhibition of RNA transcription with actinomycin D. Treatment with PDGF A/B (10 ng/ml) also produced downregulation of NPR-C mRNA, but the rate of transcript disappearance was similar to that seen after actinomycin D. Coincubation with actinomycin D inhibited the rapid disappearance of NPR-C mRNA with PMA. NPR-C mRNA levels increased four- to eightfold within 6 h after treatment with the protein synthesis inhibitor cycloheximide, but simultaneous treatment with PMA or PDGF still decreased the level of NPR-C mRNA despite the presence of cycloheximide. These results indicate that NPR-C expression is rapidly regulated by changes in the rate of catabolism of its mRNA through a protein kinase C-activated mechanism that depends on transcription. Treatment with cycloheximide induces NPR-C mRNA, but downregulation of this mRNA by either PDGF or PMA does not depend on synthesis of new protein.

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