Endothelin-1-induced mitogenic responses of Chinese hamster ovary cells expressing human endothelinA: the role of a wortmannin-sensitive signaling pathway.
In the current study, endothelin-1 (ET-1) worked as a mitogen on Chinese hamster ovary cells stably expressing human endothelinA; when applied to serum-deprived cells, ET-1 caused dose-dependent increase in [3H]thymidine incorporation and cell proliferation. No synergism was observed between the effect of ET-1 and that of insulin-like growth factor-1/basic fibroblast growth factor. Both the inhibition of intracellular Ca2+ response by phospholipase C inhibitor U73122 and the down-regulation of protein kinase C (PKC) by pretreatment with phorbol 12-myristate-13-acetate (PMA) partially blocked the ET-1-induced mitogenic responses. Wortmannin, a phosphatidylinositol-3-kinase inhibitor, caused dose-dependent inhibition of the ET-1-induced mitogenic responses in both PMA-treated and -untreated cells. Wortmannin also inhibited ET-1-induced increase in phosphatidylinositol trisphosphate formation and activation of mitogen-activated protein kinase (MAPK), whereas it failed to inhibit PMA-induced activation of MAPK. In accordance with its effect on MAPK activation, wortmannin inhibited ET-1-induced activation of Raf-B, whereas it failed to inhibit the effect of PMA. These results suggested the role of a Ca2+/PKC-independent, wortmannin-sensitive signaling pathway that linked ETA and MAPK cascade in the mitogenic signaling activated by ETA.
Sugawara
F
F
Department of Pharmacology, Faculty of Medicine, Kyoto University, Japan.
Ninomiya
H
H
Okamoto
Y
Y
Miwa
S
S
Mazda
O
O
Katsura
Y
Y
Masaki
T
T
D000595:Amino Acid Sequence; D000730:Androstadienes / Q000494:pharmacology*; D000818:Animals; D016466:CHO Cells / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D006224:Cricetinae; D065607:Cytochrome P-450 Enzyme Inhibitors; D004347:Drug Interactions; D016232:Endothelins / Q000494:pharmacology*; D004789:Enzyme Activation; D004963:Estrenes / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D008969:Molecular Sequence Data; D019869:Phosphatidylinositol 3-Kinases; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf; D011760:Pyrrolidinones / Q000494:pharmacology; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection; D000077191:Wortmannin
D000730:Androstadienes; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D065607:Cytochrome P-450 Enzyme Inhibitors; D016232:Endothelins; D004963:Estrenes; D019869:Phosphatidylinositol 3-Kinases; D010726:Phosphodiesterase Inhibitors; D017853:Phosphotransferases (Alcohol Group Acceptor); D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D019908:Proto-Oncogene Proteins c-raf; D011760:Pyrrolidinones; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin; D013755:Tetradecanoylphorbol Acetate; D000077191:Wortmannin; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione