Delineating the prime mover action of progesterone for endometrial receptivity in primates

Progesterone is essential for endometrial receptivity in primates. It is now evident that embryo-derived signal influences implantation stage endometrium under progesterone dominance, and collectively results in endometrial receptivity to implanting blastocyst. Previously, a few studies were performed using global gene profiling based on microarray technology to identify changes in gene expression between early luteal phase and mid luteal phase endometrium, however, the issue of combinatorial regulation by progesterone-dependent regulation and by embryo-derived signal on transcripts profiles during endometrial differentiation toward receptivity for blastocyst implantation in primates has not been addressed. The present review summarizes a few issues, specifically that of transforming growth factor β-tumour necrosis factor α (TGFβ-TNFα) pathways and signal transducer and activator of transcription (STAT) signalling system related to luteal phase progesterone action on endometrial receptivity in terms of its transcriptomic expression using a potent antiprogestin (mifepristone) in conception cycles of the rhesus monkey as a non-human primate model.