Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Human endometrium expresses numerous genes to achieve an optimal uterine environment for implantation and maintaining the pregnancy. In this review, we will summarize our previous observations on progestin regulated gene expression, estrogen metabolic enzymes, nitric oxide synthase, aromatase, IGF-I and II, IGFBP-1, prolactin and glycodelin. These genes are differentially activated in two types of endometrial cells during the menstrual cycle and early pregnancy. Multiple gene activation driven by progestin appears to be the major event responsible for the differentiation of endometrial cells. They play critical roles of endometrial cell function during implantation and pregnancy.