Gustavo Blanco, University of Kansas Medical Center, Cyp11a1, Dr. JoAnne Richards, Baylor College of Medicine, Mmp9, Dr. Ruth Muschel, University of Pennsylva nia, and Prl4a1, Dr. Mary Lynn Duckworth, University of Manitoba. Additional file 1, Supplemental Table S1 includes information on the source of find more info cDNAs and pri mer sequences used for the generation of cDNAs and for qRT PCR. Animals and tissue collection Holtzman Sprague Dawley rats were obtained from Har lan Laboratories. Animals were housed in an environmentally controlled facility with lights on from 0600 2000 h and were allowed free access to food and water. Timed pregnancies were generated by cohabitation of female and male animals. The pre sence of a copulatory plug or sperm in the vaginal smear was designated d0. 5 of pregnancy.

Rat placental tissues were collected on gestation d11. 5 and d18. 5. At d11. 5 of gestation, the placenta contains a mixture of proliferating and differentiating trophoblast cells, while at gestation d18. 5, the placenta is fully mature and com prised of differentiated trophoblast cells. D11. 5 tissue samples contained all trophoblast present within the placentation site, whereas d18. 5 tissue samples were restricted to the junctional zone. Placentation site dis sections were performed as previously described. Tissues for histological analysis were frozen in dry ice cooled heptane and stored at 80 C. Tissue samples for RNA extraction were frozen in liquid nitrogen and stored at 80 C. The University of Kansas Animal Care and Use Committee approved protocols for the care and use of animals.

Maintenance of Rcho 1 trophoblast stem cells Rcho 1 trophoblast stem cells were maintained at sub confluent conditions in Stem Medium as previously reported. Differentiation was induced by growing cells to near confluence in FBS supplemented culture medium and then replacing the medium with Differentiation Medium. High cell density and the absence of sufficient growth stimulatory factors facilitate trophoblast giant cell formation. Tryp sin ethylenediamine tetraacetic acid was used to passage the cells. Cells in the stem cell condi tion were grown in Stem Medium and collected 24 h after subculture to restrict the accumulation of sponta neously differentiating cells. Cells in the differentiation condition were grown for eight days in Differentiation Medium prior to harvesting unless otherwise noted.

RNA samples were extracted using TRIzol according to the manufacturers instructions. Inhibition Entinostat of PI3K LY294002 was used to inhi bit PI3K. For chronic treatment experiments, Rcho 1 trophoblast stem cells were grown to near confluence and then shifted to Differentiation Medium containing vehicle or Differentiation Medium supplemented with LY294002. This LY294002 treatment regimen was based on our earlier report, which effectively disrupts PI3K signaling in Rcho 1 trophoblast cells. Cells were harvested after eight days of treatment.