Soluble Ligands and Their Receptors in Human Embryo Development and Implantation

Abstract

Extensive evidence suggests that soluble ligands and their receptors mediate human preimplantation embryo development and implantation. Progress in this complex area has been ongoing since the 1980s, with an ever-increasing list of candidates. This article specifically reviews evidence of soluble ligands and their receptors in the human preimplantation stage embryo and female reproductive tract. The focus will be on candidates produced by the human preimplantation embryo and those eliciting developmental responses in vitro, as well as endometrial factors related to implantation and receptivity. Pathways to clinical translation, including innovative diagnostics and other technologies, are also highlighted, drawing from this collective evidence toward facilitating joint improvements in embryo quality and endometrial receptivity. This strategy could not only benefit clinical outcomes in reproductive medicine but also provide broader insights into the peri-implantation period of human development to improve fetal and neonatal health.

Hsa-miR-30d, secreted by the human endometrium, is taken up by the pre-implantation embryo and might modify its transcriptome

“…During the implantation process, the blastocyst regulates the expression and secretion of integrins β3, α4 and α1 (Simón et al, 1997), the interleukin-1 (IL-1) system (De los Santos et al, 1996), chemokines IL-8, MCP-1 and RANTES (CaballeroCampo et al, 2002), leptin (Cervero et al, 2004;González et al, 2000) and hCG (Licht et al, 2001;Paiva et al, 2011) by the endometrial epithelium during the window of implantation (WOI), the period when the endometrium is receptive to a blastocyst. The EF, a viscous fluid secreted by the endometrial glands into the uterine cavity, nurtures the embryo and constitutes the microenvironment in which the first bidirectional dialogue between the maternal endometrium and the embryo occurs during the WOI (Cha et al, 2012(Cha et al, , 2013Thouas et al, 2014;Tranguch et al, 2005).…”

Human Embryos Created by Embryo Splitting Secrete Significantly Lower Levels of miRNA-30c

“…Attempts have been made to link specific miRNAs detected in the medium with embryo ploidy status and reproductive competence to predict in vitro fertilization (IVF) outcome, and several candidates have been identified [2][3][4][5]. Although further studies are warranted, a comprehensive profile of miRNAs secreted by human preimplantation embryos in spent culture media is taking shape [6].…”

Endometrial receptivity in women with disoders in reproductive system

“…В течение менструального цикла соотношение прогестероновых рецеп-торов А-и В-изоформ (ПР-A и ПР-B) в эн-дометрии различно [4,15,19]. Воздействие прогестерона на рецепторы подтипа А, распо-ложенные в клетках стромы эндометрия, про-исходит главным образом в секреторную фазу цикла и в ранние сроки беременности [4,18].…”

“…В норме отмечено сохранение максималь-ного содержания рецепторов к прогестерону до середины секреторной фазы [19]. В секре-торную фазу цикла прогестерон вызывает прогрессирующую дифференцировку клеток эндометрия и способствует завершению под-готовки эндометрия к имплантации бласто-цисты [4].…”

“…В секре-торную фазу цикла прогестерон вызывает прогрессирующую дифференцировку клеток эндометрия и способствует завершению под-готовки эндометрия к имплантации бласто-цисты [4]. В преимплантационный период концентрация рецепторов к эстрогенам в сли-зистой оболочке матки увеличивается [19]. Эстрогены в этот промежуток времени спо-собны оказывать только модулирующее вли-яние на генную экспрессию, обусловленную прогестероном [15].…”