Epidermal growth factor stimulates mouse placental lactogen I but inhibits mouse placental lactogen II secretion in vitro.

Abstract

This study was undertaken to determine whether epidermal growth factor (EGF) regulates the secretion of mouse placental lactogen (mPL)-I and mPL-II. Primary cell cultures were prepared from placentas from days 7, 9, and 11 of pregnancy and cultured for up to 5 days. Addition of EGF (20 ng

Opposite effects of transforming growth factor alpha and epidermal growth factor on mouse placental lactogen I secretion.

“…2), confirming our previous data (11). When EGF and hTGF-a were present in the medium, the mPL-I concentration of the medium did not differ significantly between the treated and control cells (Fig.…”

“…As expected from their binding to a common receptor, effects of EGF and TGF-a have generally been similar, although qualitative and quantitative differences in the responses induced by the peptides have been observed (3)(4)(5)(6)(7)(8)(9)(10). We recently examined effects of EGF on the secretion of mouse placental lactogen I (mPL-I) and mPL-II (11), which are prolactin-like hormones produced by trophoblast giant cells (12). mPL-I is present at high concentration in maternal blood on days 9 and 10 of pregnancy (13).…”

Interleukin 6 inhibits mouse placental lactogen II but not mouse placental lactogen I secretion in vitro.

“…We have shown (23) that EGF may play some role in this shift. EGF stimulates mPL-I production and inhibits mPL-II production in vitro, and the sensitivity of mPL-II production to EGF declines as pregnancy advances.…”

“…The fact that significant inhibition of mPL-II secretion did not occur until the third day of culture suggests that ongoing differentiation of mPL-II cells may have been inhibited by IL-6. Progesterone and epidermal growth factor (EGF) have been reported to inhibit PL-II secretion in rats and mice by inhibiting differentiation of PL-II-secreting cells (23,30), suggesting differentiation of these cells could be sensitive to other regulators as well.…”

“…Cell preparations contained tissue from 130 conceptuses from day 7 of pregnancy or 65 conceptuses from days 9 or 12 of pregnancy. The tissue was dispersed in collagenase, and the cells were fractionated on a Percoll gradient as described (23). Cells banding at a density of 1.044 g/ml were suspended in culture medium [NCTC-135 supplemented with 10 mM Hepes, 25 mM NaHCO3, 1.65 mM cysteine, streptomycin (50 ,ug/ml), and penicillin G (50 units/ml)] containing 5% (vol/vol) fetal bovine serum.…”