Poster Session 2 - R4
1Frances Wong, 1,2Brian Cox
1 Dept. of Physiology, 2 Dept of Obstetrics and Gynecology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
The placenta is a transient yet unique organ of pregnancy which arises from the outer trophectoderm layer of the blastocyst during early human development. In addition to transporting nutrients, waste, hormones, and endocrine factors, the placenta also provides physical and immunological protection to the developing fetus and produces hormones to maintain pregnancy. Proper placenta development is essential to healthy embryo development but unfortunately, our understanding of early placentation and trophoblast development is very limited with respect to their embryonic counterpart largely due to our inability to isolate trophoblast stem cells and maintain these cells in culture. Primary cultures terminally differentiate within days and immortalized cell lines are commonly derived from tumorigenic tissue and consequently are inaccurate representation of normal development. While the many strategies to derive mouse trophoblast stem cells have been unsuccessful when applied to human systems, reports claim human trophoblast cell types can be derived from BMP4 treatment of embryonic stem cells although the identity of these cells remain controversial. Using available microarray data of in vitro derived human trophoblast and integration with other datasets of human ESC differentiation we have identified that BMP4 treatment of human cells generates a majority of cardiac cell types. This analysis identified a surprising level of gene co-option by the trophoblast from heart development gene networks. Gene expression analysis of early uncultured human trophoblast cells supports the absence of cardiac markers in primary cells.