LIF–STAT signaling in decidual cells: a possible role in embryo implantation and early pregnancy

Abstract

In this study, we investigate the effects of miRNA-138-5p and probable G-protein coupled receptor 124 (GPR124)-regulated inflammasome and downstream leukemia inhibitory factor (LIF)–STAT and adhesion molecule signaling in human decidual stromal cells. After informed consent was obtained from women aged 25–38 years undergoing surgical termination of the normal pregnancy and spontaneous miscarriage after 6–9 weeks of gestation, human decidual stromal cells were extracted from the decidual tissue. Extracellular vesicles (EVs) with microRNA (miRNA) between cells have been regarded as critical factors for embryo–maternal interactions on embryo implantation and programming of human pregnancy. MicroRNA-138-5p acts as the transcriptional regulator of GPR124 and the mediator of downstream inflammasome. LIF-regulated STAT activation and expression of integrins might influence embryo implantation. Hence, a better understanding of LIF–STAT and adhesion molecule signaling would elucidate the mechanism of microRNA-138-5p- and GPR124-regulated inflammasome activation on embryo implantation and pregnancy. Our results show that microRNA-138-5p, purified from the EVs of decidual stromal cells, inhibits the expression of GPR124 and the inflammasome, and activates the expression of LIF–STAT and adhesion molecules in human decidual stromal cells. Additionally, the knockdown of GPR124 and NLRP3 through siRNA increases the expression of LIF–STAT and adhesion molecules. The findings of this study help us gain a better understanding the role of EVs, microRNA-138-5p, GPR124, inflammasomes, LIF–STAT, and adhesion molecules in embryo implantation and programming of human pregnancy.