Decidual Activation: Abundance and Localization of Prostaglandin F2α Receptor (FP) mRNA and Protein and Uterine Activation Proteins in Human Decidua at Preterm Birth and Term Birth

ObjectiveTo study how the decidua contributes to parturition, we examined prostaglandin F2α concentrations as well as prostaglandin 15-hydroxy dehydrogenase, prostaglandin F2α receptor, matrix metalloproteinases 2 and 9, oxytocin receptor, prostaglandin-H synthase-2, and the prostaglandin E2 receptor expression in human decidua.Materials and methodsDecidual samples were isolated from placentas collected from patients at preterm not in labor (PTNIL), preterm labor (PTL), term not in labor (TNIL), and term labor (TL). For immunohistochemistry, fresh membranes which included chorion, amnion and decidua from term patients were collected.ResultsProstaglandin F2α receptor mRNA was low in all preterm patients and then significantly increased towards term (p = 0.049). Prostaglandin F2α receptor protein was identified in the amnion epithelium and mesoderm, chorion trophoblasts and decidua by immunohistochemistry, and levels were highest at TNIL (p = 0.007) as measured by western blot. Prostaglandin F2α levels were higher at PTNIL than TNIL. Matrix metalloproteinases 2 and 9 protein and pro-enzyme activities were higher at TL than TNIL. There were no significant changes among the groups for any of the other factors measured.ConclusionsThese results suggest that the induction of Prostaglandin F2α receptor at term may facilitate the decidua contribution to parturition, and its regulation and role should be examined further.