Effects of galectin-1 on regulation of progesterone production in granulosa cells from pig ovaries in vitro.
The detection of galectin-1 (gal-1) in pig granulosa cell lysates by immunoblotting and its cytosolic as well as membrane-associated localization prompted us to study its effects on cell proliferation and regulation of progesterone synthesis. The lectin stimulated the proliferation of granulosa cells from pig ovaries cultured in serum-free medium. Gal-1 inhibited the FSH-stimulated progesterone synthesis of granulosa cells. This inhibitory effect was strongly reduced by the disaccharidic competitor lactose at 30 mM. The absence of inhibitory effects on dibutyryl-cAMP (db-cAMP), forskolin, and pregnenolone-enhanced cellular progesterone synthesis suggests that gal-1interferes with the receptor-dependent mechanism of FSH-stimulated progesterone production. In FSH-stimulated granulosa cells, western blot analysis revealed the gal-1-mediated suppression of the cytochrome P450-dependent cholesterol side chain cleavage enzyme (P450(SCC)) that catalyzes the conversion of cholesterol to pregnenolone. In the presence of 30 mM lactose, the gal-1-reduced P450(SCC) expression was prevented. Strongly reduced mRNA levels were recorded for P450(SCC) and 3beta-hydroxysteroid dehydrogenase/isomerase (3beta-HSD) when FSH-stimulated granulosa cells were cultured in the presence of gal-1. We conclude that gal-1 exerts its inhibitory effect on steroidogenic activity of granulosa cells by interfering the hormone-receptor interaction resulting in decreased responses to FSH stimulation.
Walzel
Hermann
H
University of Rostock, Institute of Medical Biochemistry and Molecularbiology, Schillingallee 70, 18057 Rostock, Germany. hermann.walzel@med.uni-rostock.de
Brock
Josef
J
Pöhland
Ralf
R
Vanselow
Jens
J
Tomek
Wolfgang
W
Schneider
Falk
F
Tiemann
Ute
U
D000818:Animals; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D005260:Female; D005640:Follicle Stimulating Hormone / Q000037:antagonists & inhibitors; D037483:Galectin 1 / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007785:Lactose / Q000031:analogs & derivatives / Q000494:pharmacology; D010053:Ovary / Q000166:cytology* / Q000502:physiology; D011284:Pregnenolone / Q000494:pharmacology; D011374:Progesterone / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000378:metabolism*; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000235:genetics; D013552:Swine
D065607:Cytochrome P-450 Enzyme Inhibitors; D037483:Galectin 1; D012333:RNA, Messenger; D005576:Colforsin; D011374:Progesterone; D011284:Pregnenolone; D005640:Follicle Stimulating Hormone; D003577:Cytochrome P-450 Enzyme System; D000242:Cyclic AMP; D007785:Lactose