Epidermal growth factor (EGF) receptor localization in cultured human granulosa lutein cells and the stimulation of progesterone production by EGF and transforming growth factor-alpha (TGF-alpha).
OBJECTIVE
The purpose of this study was to investigate the expression of EGF receptor (EGF-R) in human granulosa cells undergoing luteinization and progesterone production by these cells in response to EGF an TGF-alpha alone or in combination with luteinizing hormone (LH). Granulosa cells were obtained from IF patients following oocyte retrieval 34 to 36 hr post-hCG injection. EGF receptor was localized in cells by means of immunoperoxidase staining using a polyclonal primary antibody directed against the human EGF-R. To assess progesterone production, cells were seeded overnight, washed, and cultured with the growth factors +/- LH. Medium and treatments were changed every 24 hr for 3 days.


RESULTS
Specific EGF-R staining was observed in the cultured cells compared to those incubated with antibody that was preabsorbed with a 10-fold excess of EGF. Basal progesterone accumulation per 24-hr period was stimulated dose dependently on each day of culture, by both EGF (up to 3.5-fold at 5 or 50 ng/ml) and TGF-alpha (up to 4-fold at 50 ng/ml). The addition of LH alone also stimulated progesterone accumulation daily, and this effect was further enhanced dose dependently by cotreatment with EGF or TGF-alpha. Furthermore, tyrphostin, an EGF-R-specific tyrosine kinase inhibitor, inhibited both basal and growth factor-stimulated progesterone production.


CONCLUSIONS
These data suggest an EGF receptor-mediated physiological role for EGF and TGF-alpha in human luteal function involving an autocrine and/or a paracrine stimulation of progesterone production.
Tekpetey
F R
FR
Department of Obstetrics & Gynaecology, University of Western Ontario, London, Canada.
Daniel
S A
SA
Yuzpe
A
A
D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000032:analysis*; D005260:Female; D006107:Granulosa Cells / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008184:Luteal Cells / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D007986:Luteinizing Hormone / Q000494:pharmacology; D009570:Nitriles / Q000494:pharmacology; D011374:Progesterone / Q000096:biosynthesis*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D009570:Nitriles; D016211:Transforming Growth Factor alpha; D011374:Progesterone; D004815:Epidermal Growth Factor; D007986:Luteinizing Hormone; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases