REGULATION OF TRANSFERRIN RECEPTOR SYNTHESIS BY HUMAN CYTOTROPHOBLASTCELLS IN CULTURE

The aim of this study was to examine the capacity of the syncytiotroph oblast to regulate transferrin receptor (TfR) synthesis in response to modulations in maternal iron supply. The model used was the primary t rophoblast cell culture. Trophoblast cells isolated from term human pl acentas were cultured in iron-poor (Medium 199), iron-depleted (desfer rioxamine (DFO)) and iron-supplemented (diferric transferrin (hTf-2Fe) , ferric ammonium citrate (FAC)) medium. TfR synthesis was reduced in response to hTf-2Fe supplementation. FAC did not modulate TfR synthesi s. Iron deprivation by DFO resulted in clear stimulation of TfR synthe sis. These results show that the differentiating trophoblast cells res pond to pertubations in the (transferrin-mediated) iron supply by adju stments in the rate of TfR synthesis. Taking syncytiotrophoblast in cu lture as model for the maternal/fetal interface in vivo, our results w ould suggest that the placenta is able to make short term adjustments of the capacity for iron uptake.