Involvement of epidermal growth factor (EGF)/EGF receptor autocrine and paracrine mechanism in human trophoblast cells: functional differentiation in vitro

Abstract

We have studied the expression of epidermal growth factor (EGF) and EGF receptors (EGF-R) in isolated human trophoblast cells at various stages of differentiation and also the biological significance of the EGF/EGF-R autocrine and paracrine mechanism. Cytotrophoblast cells were isolated from human placental tissues of 6-9 weeks of gestation. Trophoblast cells underwent morphological and functional differentiation during in vitro culture. The expression of EGF and EGF-R protein and mRNA was studied in trophoblast cells cultured for 0-5 days, using immunocytochemical staining, and reverse transcription and polymerase chain reaction. Monoclonal antibodies (mAbs) against EGF and EGF-R showed specific staining in trophoblast cells at all stages of differentiation. Both EGF and EGF-R gene transcripts were detected in RNA samples isolated from trophoblast cells at all stages. These data suggest the presence of an EGF/EGF-R autocrine and paracrine mechanism in human trophoblast cells. Next, we examined the biological significance of this mechanism on trophoblast cell differentiation in vitro. EGF added to the culture medium significantly increased human chorionic gonadotrophin-beta (hCG-beta) secretion and, more importantly, anti-EGF neutralizing mAbs significantly reduced both hCG-beta and human placental lactogen secretion from trophoblast cells in culture. All these results suggest that human trophoblast cells express both EGF and EGF-R, and that EGF may play an important role in the functional differentiation of human trophoblast cells.

Epidermal Growth Factor Stimulation of Trophoblast Differentiation Requires MAPK11/14 (p38 MAP Kinase) Activation

“…Morrish et al [7] documented increased release from primary human trophoblasts relative to Day 1, which is compatible with our studies. Amemiya et al [12] cultured primary trophoblasts to show high levels of CGB secreted on Day 1, which decreased and again peaked at Day 4-5, then decreased thereafter. These cultures released CGB over time much as explant cultures do ( [30]; this paper, Fig.…”

“…Expression of human chorionic gonadotropin (b-hCG, CGB) has also been used as a marker of villous trophoblast differentiation [1]. However, EGF has been shown to both increase [7,12,13] and decrease [14] CGB production in cultured trophoblasts.…”

Epidermal growth factor inhibits cytokine-induced apoptosis of primary human trophoblasts

“…EGF is present in the decidua and amniotic fluid but the precise source and the regulation of its production during pregnancy remain somewhat controversial (Hoffman and Abramowicz, 1990;Bass et al, 1994). Trophoblasts can synthesize EGF (Hofmann et al, 1991;Amemiya et al, 1994) as well as TGFa, a growth factor with substantial sequence homology to EGF and that binds to the EGF receptor with the same affinity (Lysiak et al, 1993). Since trophoblasts express abundant EGF receptor (Tavare and Holmes, 1989), it is reasonable to hypothesize that an EGFPTGFcl autocrine/paracrine loop may be instrumental in regulating the sensitivity of these cells to cytokine-mediated killing.…”

Amphiregulin acts as an autocrine growth factor in two human polarizing colon cancer lines that exhibit domain selective EGF receptor mitogenesis

“…These ligands have been shown to mediate various cellular functions, including proliferation, differentiation and migration (Basson et al, 1992(Basson et al, , 1994Amemiya et al, 1994;Chen et al, 1994;Traverse et al, 1994). In epithelial cells cultured as a flat monolayer on plastic, it has been shown that TGF-α and AR can act in an autocrine manner (Culouscou et al, 1992;Johnson et al, 1992;Li et al, 1992;Ziober et al, 1993;Qi et al, 1994).…”