Roles of prostaglandin signaling in implantation and decidualization.

Embryo implantation and subsequent decidualization are crucial processes for the establishment of a healthy pregnancy, but the molecular mechanisms underlying these processes remain unclear. Prostaglandins (PGs), which are synthesized from arachidonic acid via a pathway involving cyclooxygenase (COX) as the rate-limiting enzyme, have been shown to regulate implantation. Recently, the COX isozymes COX-1 and COX-2 were found to play distinct roles in implantation. Furthermore, the PG receptors involved in decidualization have been identified. In this review, we summarize the role of PGs in implantation from the viewpoint of COX and PG receptors, as well as the interplay between PGs and lysophosphatidic acid upon embryo implantation.