scholarly journals Diacylglycerol induces deacylation of phosphatidylinositol and mobilization of arachidonic acid in mouse macrophages Comparison with induction by phorbol diester

1986 ◽  
Vol 239 (3) ◽  
pp. 685-690 ◽  
Author(s):  
A Emilsson ◽  
J Wijkander ◽  
R Sundler
Keyword(s):  
Arachidonic Acid ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Intracellular Calcium ◽  
Phorbol Myristate Acetate ◽  
Myristate Acetate ◽  
Sequence Of Events ◽  
Kinase C ◽  
Mouse Macrophages ◽  
Activate Protein Kinase

1,2-Dioctanoyl-sn-glycerol (2-50 microM) was found, like phorbol myristate acetate (greater than or equal to 3 nM) to stimulate phospholipase A-type cleavage of phosphatidylinositol and the release of arachidonic acid from macrophage phospholipids. The 1,3 isomer of dioctanoylglycerol was inactive, whereas racemic 1,2-dioctanoylglycerol was half as potent as the 1,2-sn enantiomer. Dioctanoylglycerol-induced deacylation of phosphatidylinositol was only partly dependent on extracellular calcium but was more severely inhibited by depletion of intracellular calcium. Chlorpromazine inhibited the deacylation of phosphatidylinositol, whereas inhibitors of cyclo-oxygenase and lipoxygenase were ineffective. Since both phorbol myristate acetate and 1,2-dioctanoyl-sn-glycerol are known to activate protein kinase C, the results suggest that this kinase is involved in the sequence of events leading to release of arachidonic acid in macrophages.

scholarly journals Requirement for diacylglycerol and protein kinase C in HeLa cell-substratum adhesion and their feedback amplification of arachidonic acid production for optimum cell spreading.

1993 ◽  
Vol 4 (3) ◽  
pp. 271-281 ◽  
Author(s):  
J S Chun ◽  
B S Jacobson
Keyword(s):  
Arachidonic Acid ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Hela Cell ◽  
Cell Attachment ◽  
Cell Spreading ◽  
Subsequent Formation ◽  
Sequence Of Events ◽  
Kinase C ◽  
Pkc Activation

Release of arachidonic acid (AA) and subsequent formation of a lipoxygenase (LOX) metabolite(s) is an obligatory signal to induce spreading of HeLa cells on a gelatin substratum (Chun and Jacobson, 1992). This study characterizes signaling pathways that follow the LOX metabolite(s) formation. Levels of diacylglycerol (DG) increase upon attachment and before cell spreading on a gelatin substratum. DG production and cell spreading are insignificant when phospholipase A2 (PLA2) or LOX is blocked. In contrast, when cells in suspension where PLA2 activity is not stimulated are treated with exogenous AA, DG production is turned on, and inhibition of LOX turns it off. This indicates that the formation of a LOX metabolite(s) from AA released during cell attachment induces the production of DG. Consistent with the DG production is the activation of protein kinase C (PKC) which, as with AA and DG, occurs upon attachment and before cell spreading. Inhibition of AA release and subsequent DG production blocks both PKC activation and cell spreading. Cell spreading is also blocked by the inhibition of PKC with calphostin C or sphingosine. The inhibition of cell spreading induced by blocking AA release is reversed by the direct activation of PKC with phorbol ester. However, the inhibition of cell spreading induced by PKC inhibition is not reversed by exogenously applied AA. In addition, inhibition of PKC does not block AA release and DG production. The data indicate that there is a sequence of events triggered by HeLa cell attachment to a gelatin substratum that leads to the initiation of cell spreading: AA release, a LOX metabolite(s) formation, DG production, and PKC activation. The data also provide evidence indicating that HeLa cell spreading is a cyclic feedback amplification process centered on the production of AA, which is the first messenger produced in the sequence of messengers initiating cell spreading. Both DG and PKC activity that are increased during HeLa cell attachment to a gelatin substratum appear to be involved. DG not only activates PKC, which is essential for cell spreading, but is also hydrolyzed to AA. PKC, which is initially activated as consequence of AA production, also increases more AA production by activating PLA2.

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.

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