Involvement of protein kinase C-dependent mitogen-activated protein kinase p44/42 signaling pathway for cross-talk between estradiol and transforming growth factor-beta3 in increasing basic fibroblast growth factor in folliculostellate cells.
We have recently shown that TGF-beta3, in the presence of estradiol, increases the release of basic fibroblast growth factor (bFGF) from folliculostellate (FS) cells in the pituitary. We determined the interactive effects of TGF-beta3 and estradiol on bFGF production and release from FS cells, and the role of the MAPK pathway in TGF-beta3 and estradiol interaction. We found that TGF-beta3 and estradiol alone moderately increased cell content and release of bFGF from FS cells; but together, they markedly increased the peptide. Estradiol and TGF-beta3 alone moderately activated MAPK p44/42; together they produced marked activation of MAPK p44/42. Pretreatment of FS cells with an MAPK kinase 1/2 inhibitor or with protein kinase C inhibitors suppressed the activation of MAPK p44/42, bFGF release, and protein level increases, all of which were induced by TGF-beta3 and estradiol. Estradiol and TGF-beta3, either alone or in combination, increased the levels of active Ras. Furthermore, bFGF induction by TGF-beta3 and estradiol was blocked by overexpression of Ras N17, a dominant negative mutant of Ras p21. Estrogen receptor blocker ICI 182,780 failed to prevent estrogen's and TGF-beta3's effects on bFGF. These data suggest that an estradiol receptor-independent protein kinase C- activated Ras-dependent MAPK pathway is involved in the cross-talk between TGF-beta3 and estradiol to increase bFGF production and/or release from FS cells.
Chaturvedi
Kirti
K
Endocrinology Program, Biomedical Division of the Center of Alcohol Studies and Department of Animal Sciences, Rutgers, The State University of New Jersey, 84 Lipman Drive, New Brunswick, NJ 08901, USA.
Sarkar
Dipak K
DK
D000818:Animals; D002460:Cell Line; D004347:Drug Interactions; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D000077267:Fulvestrant; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D011960:Receptors, Estrogen / Q000037:antagonists & inhibitors; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053782:Transforming Growth Factor beta3
D004791:Enzyme Inhibitors; D011960:Receptors, Estrogen; C509046:Tgfb3 protein, rat; D016212:Transforming Growth Factor beta; D053782:Transforming Growth Factor beta3; D016222:Fibroblast Growth Factor 2; D000077267:Fulvestrant; D004958:Estradiol; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases