Machida T, Taga M, Minaguchi H. Effects of epidermal growth factor and transforming growth factor alpha on the mouse trophoblast outgrowth in vitro. Eur J Endocrinol 1995;133:741–6. ISSN 0804–4643
In order to analyze the involvement of growth factors in the implantation mechanism, we examined the direct effects of epidermal growth factor (EGF) and transforming growth factor alpha (TGF-α) on trophoblast outgrowth of the mouse blastocyst in vitro. ICR mouse blastocysts were cultured for 4 days on a culture plate in medium containing EGF or TGF-α or conditioned medium obtained from cultured endometrial epithelial cells. Blastocysts were also co-cultured with endometrial epithelial cells. The trophoblast outgrowth of these cultured blastocysts was observed daily and the percentage of outgrowing embryos was calculated and analyzed statistically by the chi-squared test. Analysis for the specific binding of 125I-EGF in outgrown trophoblasts was carried out by autoradiography. The coculture (days 3 and 4) and the presence of EGF (10 ng/ml, day 4), TGF-α (1 ng/ml, day 3; 10 ng/ml, days 2 and 3; 50 ng/ml, days 2–4) or conditioned medium (days 3 and 4) significantly stimulated the rate of trophoblast outgrowth. Preincubation of the conditioned medium with monoclonal anti-EGF or anti-TGF-α antibody suppressed the stimulatory effect of the conditioned medium on trophoblast outgrowth. The specific 125I-EGF binding in outgrown trophoblasts was demonstrated by autoradiography. These results suggest that EGF and TGF-α play an important role in the implantation process by directly stimulating trophoblast development.
Michiyoshi Taga, Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236, Japan
Transforming growth factor alpha, but not epidermal growth factor, promotes the survival of sensory neurons in vitro
