title: Signal transduction cascade in staurosporine-induced prostaglandin E(2) production by rat peritoneal macrophages.
abstract: The possible participation of phosphatidylinositol (PI) 3-kinase, p44/42 mitogen-activated protein (MAP) kinases and protein kinase C (PKC) in staurosporine-induced prostaglandin E(2) (PGE(2)) production was investigated pharmacologically in rat peritoneal macrophages. When the cells were incubated in the presence of staurosporine (63 nM), phosphorylation of p44/42 MAP kinases and cytosolic phospholipase A(2) (cPLA(2)) was induced at 15 min and increased until 60 min, whereas PGE(2) production and expression of cyclooxygenase-2 (COX-2) protein began to increase at 2 h and increased thereafter. Both PD98059 and U0126, MAP kinase/extracellular signal-regulated kinase (ERK) kinase inhibitors, and LY294002, a PI 3-kinase inhibitor, inhibited staurosporine-induced phosphorylation of p44/42 MAP kinases and cPLA(2) and PGE(2) production. Moreover, U0126 inhibited staurosporine-induced arachidonic acid release at 1 h. Although PD98059 and U0126 at 30 microM partially inhibited staurosporine-induced COX-2 protein expression, they completely inhibited staurosporine-induced PGE(2) production. LY294002 at 100 microM did not inhibit staurosporine-induced expression of COX-2 protein. In contrast, Ro-31-8220, a PKC inhibitor, completely inhibited staurosporine-induced PGE(2) production and COX-2 protein expression at 8 h but did not inhibit staurosporine-induced phosphorylation of p44/42 MAP kinases and cPLA(2). These findings suggest that staurosporine induces PGE(2) production by two mechanisms. One is cPLA(2) phosphorylation through a signal transduction pathway from PI 3-kinase to p44/42 MAP kinases, by which arachidonic acid, a substrate for COX-1 and COX-2, is increased. The other is COX-2 protein expression, which is induced mainly by activation of PKC and partially by activation of p44/42 MAP kinases; thus, arachidonic acid is metabolized to PGE(2).
authors.affiliation: Department of Pathophysiological Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba Aramaki, Aoba-ku, Sendai, Miyagi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamaki
authors.forename: T
authors.initials: T
authors.lastname: Yonezawa
authors.forename: K
authors.initials: K
authors.lastname: Ohuchi
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007527:Isoenzymes / Q000096:biosynthesis / Q000378:metabolism; D007700:Kinetics; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010741:Phospholipases A / Q000378:metabolism; D010766:Phosphorylation; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D019311:Staurosporine / Q000494:pharmacology*
chemical_list: D016718:Arachidonic Acid; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D015232:Dinoprostone; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010741:Phospholipases A; D011451:Prostaglandin-Endoperoxide Synthases; D011493:Protein Kinase C; D019311:Staurosporine