Oestrogen synthetase (aromatase) and hormone secretion in primary cultures of human placental trophoblast cells. Effects of cyclic AMP addition at the start of culture in attached and unattached cell populations.
Term placental trophoblast cells, released by trypsin digestion of placental villi, purified on a Percoll gradient and grown in serum-containing medium, differentiate within 24 to 48 h in culture from mononucleated cytotrophoblast-like cells at the start of culture to highly multinucleated giant (syncytiotrophoblast-like) cells that are more active in hormonogenesis. To determine the changes in hormone biosynthesis and secretion that occur early in the trophoblast differentiation process in vitro, freshly isolated placental cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM) containing 20 per cent FBS, in the presence and absence of cAMP for up to 48 h. Cell attachment and growth, oestrogen synthetase (aromatase) activity in attached and unattached cells, and secretion of human chorionic gonadotropin (hCG) and progesterone were studied. The aromatase specific activity, low in freshly isolated cells, increased fourfold in attached cells by 3 h, and achieved a 10- to 15-fold increase by 40 to 48 h. In attached cells grown with cAMP, aromatase activity was further stimulated by about fourfold, relative to the control. The aromatase activity of the unattached cells removed from the culture dishes at various times up to 48 h showed a biphasic response: the activity decreased by 18 h and then increased back to the fresh cell levels. The effect of cAMP on aromatase in these unattached cells was manifested by a two-fold stimulation of activity by 18 h, relative to control unattached cells. Secretion of hCG from both attached and unattached cells remained at a low level (less than 200 ng/mg protein) in control cells; in the presence of cAMP, hCG secretion was stimulated by tenfold after 40 h.(ABSTRACT TRUNCATED AT 250 WORDS)
Lobo
J O
JO
Department of Biological Sciences, State University of New York, Buffalo 14260.
Bellino
F L
FL
D001141:Aromatase / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism*; D013997:Time Factors; D014327:Trophoblasts / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D011374:Progesterone; D000242:Cyclic AMP; D001141:Aromatase