Scientists at the University of Sheffield have identified a protein, involved in the development of the human placenta, may also help embryos implant in the womb - something which could improve treatments for recurrent miscarriages and pre-eclampsia.

The pioneering study shows that a protein called Syncytin-1, which was the result of a viral infection of our primate ancestors 25 million years ago, is first secreted on the surface of a developing embryo even before it implants in the womb.

This means the protein is likely to play a major role in helping embryos stick to the womb as well as the formation of the placenta.

This fundamental understanding of the earliest stages of human embryo development is crucial for improving current treatments for a variety of stressful complications during pregnancy such as recurrent miscarriages, foetal growth restriction syndrome and pre-eclampsia - a life-threatening condition of elevated maternal blood pressure during pregnancy.

Researchers will now investigate whether the level of Syncytin-1 secretion on the pre-implantation embryo is somehow related to outcome of pregnancy in women undergoing IVF.

"Until now we didn't know this protein was expressed so early in the embryo.Interestingly the Syncytin-1 protein was mainly secreted in the cells of the embryo, called polar trophoblast cells, which will first stick to the cells of the womb called endometrial epithelial cells. In the lab we discovered the trophoblast cells that secrete Syncytin-1 not only fuse together - which in the body will form an essential barrier to protect the embryo - but also secrete nano-vesicles called exosomes.
These exosomes may communicate with cells in other areas of the mother to prepare her for pregnancy. If this doesn't happen properly at the earliest stages it may cause problems throughout pregnancy."

http://www.sheffield.ac.uk/news/nr/miscarriage-treatments-medicine-protein-preeclampsia-scientists-embryo-fetus-pregnancy-zika-1.574328