Differential involvement of protein kinase C in activating cytosolic phospholipase A2 in alveolar macrophages and monocyte differentiated U937 cells

1995 ◽  
Vol 44 (S2) ◽  
pp. S139-S140 ◽  
Author(s):  
M. T. Withnall ◽  
A. M. Pennington ◽  
M. Hagen
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase A2 ◽  
Alveolar Macrophages ◽  
Cytosolic Phospholipase A2 ◽  
U937 Cells ◽  
Cytosolic Phospholipase ◽  
Kinase C ◽  
Differential Involvement

Complement C5b-9 activates cytosolic phospholipase A2 in glomerular epithelial cells

1995 ◽  
Vol 269 (5) ◽  
pp. F739-F749 ◽  
Author(s):  
A. V. Cybulsky ◽  
J. C. Monge ◽  
J. Papillon ◽  
A. J. McTavish
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Prostaglandin E2 ◽  
Phospholipase A2 ◽  
Molecular Mass ◽  
Membranous Nephropathy ◽  
Cytosolic Phospholipase A2 ◽  
Glomerular Epithelial Cell ◽  
Cytosolic Phospholipase ◽  
Kinase C

In rat membranous nephropathy, complement C5b-9 induces glomerular epithelial cell (GEC) injury and proteinuria, which, in some models, is partially mediated by eicosanoids. By analogy, sublytic C5b-9 injures plasma membranes and releases arachidonic acid (AA) and eicosanoids in cultured rat GEC. In this study, we demonstrate that, in GEC, sublytic C5b-9 stably increased the activity of a high-molecular-mass cytosolic phospholipase A2 (PLA2), which we identified as "cPLA2." This increase was abolished with inhibitors of protein kinase C. C5b-9 did not affect low-molecular-mass membrane-associated or secretory PLA2 activities. In GEC that stably overexpress cPLA2 activity and protein (produced by transfection of cPLA2 cDNA), immunoblot analysis showed that sublytic C5b-9 induced a decreased mobility of cPLA2, consistent with cPLA2 phosphorylation. Incubation of cPLA2-transfected GEC with sublytic C5b-9 significantly increased production of free AA and prostaglandin E2, whereas, in control GEC, the C5b-9-induced changes in free AA and prostaglandin E2 were small. Furthermore, both C5b-9-dependent sublytic cytotoxicity and cytolysis were enhanced in GEC overexpressing cPLA2, compared with control cells. Thus C5b-9 increased cPLA2 activity, probably via phosphorylation involving a protein kinase C-dependent pathway. Phospholipid hydrolysis by cPLA2 resulted in release of substrate for eicosanoid synthesis and in enhancement of C5b-9-dependent GEC injury. Both processes may facilitate glomerular damage in membranous nephropathy.

Evidence that cytosolic phospholipase A2 is down-regulated by protein kinase C in intact human platelets stimulated with fluoroaluminate

FEBS Letters ◽  
1999 ◽  
Vol 450 (1-2) ◽  
pp. 39-43 ◽  
Author(s):  
Fabio Nucciarelli ◽  
Paolo Gresele ◽  
Vincenza Nardicchi ◽  
Serena Porcellati ◽  
Lara Macchioni ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase A2 ◽  
Human Platelets ◽  
Cytosolic Phospholipase A2 ◽  
Cytosolic Phospholipase ◽  
Kinase C
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