YALE (US)—Healthy embryos contain a unique protein that directs attachment and helps the mother adapt to pregnancy by modulating maternal immunity and influencing the remodeling of uterine cells.

The protein, Preimplantation Factor, “appears to be essential for pregnancy to succeed,” says Michael Paidas, associate professor at Yale University and co-director of the Women and Children’s Center for Blood Disorders.

“For several decades, investigators have tried to isolate a compound that was absolutely required for pregnancy. We believe that Preimplantation Factor is in fact that compound.”

Details of the findings appear in the current issue of the American Journal of Obstetrics and Gynecology.

Paidas and his colleagues conducted a genomic and proteomic study of both non-pregnant and pregnant uterine stromal cells, which are positioned directly beneath the uterine lining (epithelium).

When these cells in culture were exposed to Preimplantation Factor, over 500 maternal genes and several proteins were significantly altered.

Interestingly, Paidas says, profound changes were detected precisely in those pathways and networks critical for implantation.

Preimplantation Factor was discovered by co-author Eytan R. Barnea, clinical associate professor of obstetrics, gynecology & reproduction at the University of Medicine and Dentistry of New Jersey.

Barnea eventually synthesized Preimplantation Factor so that the replicated form is identical to the native compound.

Studies are ongoing to establish Preimplantation Factor as a diagnostic test for pregnancy viability, not only in humans but in animals as well, since it appears to be universally present in mammals.

There is even greater interest in the potential therapeutic applications, both in pregnancy and in other conditions such as autoimmune disease and transplantation, Paidas says.

Preclinical studies are being conducted to pave the way for eventual human clinical trials.

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