Do molecular signals from the conceptus influence endometrium decidualization in rodents?

Abstract

A critical period in establishing pregnancy occurs after the onset of implantation but before placental development. Evidence strongly suggests that abnormalities occurring during this period can result in pregnancy termination or in pre-eclampsia; the latter may lead to small-for-gestational-weight offspring that are likely to be unhealthy. Clearly, events occurring in the endometrium during the implantation process are crucial for proper fetal development and for optimal offspring health. In several mammalian species bi-directional communication between the conceptus and endometrium during implantation is required for successful pregnancy. Although different implantation and placentation modes occur in different mammalian species, common aspects of this bi-directional signaling may exist. The molecular signals from the trophoblast cells of the conceptus, which direct endometrial changes during implantation progression, are well known in some non-rodent species. Currently, we know little about such signaling in rodents during implantation progression, when the endometrium undergoes decidualization. This review focuses on data that support the hypothesis that paracrine signals from the rodent conceptus influence decidualization. Where possible, these findings are compared and contrasted to information currently known in other species that exhibit different implantation modes.

Physiological and molecular determinants of embryo implantation

“…The disappearance of primary decidual zone which forms a barrier surrounding the embryo and reduced immune cell population in deciduoma further emphasize the importance of embryo-uterus dialogue (Herington and Bany, 2007b; Wang et al, 2004d). Using microarray approaches, the differentially expressed genes responsive to (Bany and Cross, 2006; Herington and Bany, 2007a; Herington and Bany, 2007b, 2009; Herington et al, 2009; Kashiwagi et al, 2007; McConaha et al, 2011)the living embryo versus artificial stimuli further prove the paracrine signals from the embryo regulating the decidua development (Bany and Cross, 2006; Herington and Bany, 2007a; Herington and Bany, 2007b, 2009; Herington et al, 2009; Kashiwagi et al, 2007; McConaha et al, 2011). Collectively, these findings highlight the necessity of embryo-derived signals for normal implantation and decidualization.…”

Microarray assessment of the influence of the conceptus on gene expression in the mouse uterus during decidualization

“…Previous work has suggested that the mammalian conceptus may secrete paracrine factors that can regulate endometrial gene expression during decidualization (reviewed in (Herington & Bany 2009)). Clear examples of this exist in several species.…”

PI3K, AKT, and P-AKT levels in thin endometrium

“…AKT is mainly distributed in the luminal and glandular epithelial cells of the uterus in mice before follicular implantation. However, AKT was also detected in decidualized matrix cells (Herington and Bany, 2009). These findings indicate that activation of AKT is involved in the remodeling of endometrium and egg implantation, while miscarriage and infertility in women with thin endometrium could be associated with decreased expression of PI3K and AKT.…”