Regional and temporal regulation of prostaglandin E2 receptor expression: a role for decidual activation in term labor (911.7)

Abstract

Objective: To assess if expression of prostaglandin E2 receptors (EP1, EP2, EP3 and EP4) are spatially or temporally regulated in decidua with labour onset.Methods: Decidua biopsies from caesarean section deliveries, of labouring (TL) and non‐labouring (TNL) women and from both upper (US) and lower segment (LS) regions of the uterus were collected (n=12/group). Real‐time RT‐PCR was used to quantify levels of EP1‐4 gene expression.Results: All four EPs are expressed in US and LS decidua. Expression of EP1, EP2, and EP4 is higher in LS compared to US in TNL decidua, but did not change with labor initiation. In contrast, EP3 was significantly higher than the other EP receptors in both US and LS in TNL decidua. The EP3 mRNA levels decrease in LS but not US decidua with labor initiation.Conclusions: The presence of four EP receptor subtypes within the decidua in labouring and non‐labouring women suggests that prostaglandin E2 plays an active biological role during pregnancy and labour via differential EP interaction. Our observation that EP3 levels change with labor onset suggests that EP3 are the predominant mediators of PGE2 activity in the decidua at term. These findings on differential EP regulation in decidua with labour are important for the understanding of the underlying mechanisms that govern uterine contractility and quiescence.Grant Funding Source: Supported by Canadian Institute of Health Research and Alberta Innovates‐Health Solutions