MicroRNA and Embryo Implantation

Abstract

Problem In mammals, implantation involves interactions between an activated blastocyst and a receptive endometrium. There are controversies on the role of microRNAs in preimplantation embryo development. The actions of endometrial microRNAs on implantation are beginning to be understood. Method of Study Review of literature on microRNAs in preimplantation embryos and endometrium. Results Emerging evidence suggests a role of microRNAs in blastocyst activation and implantation. Differential expression of microRNAs is found between receptive and non‐receptive endometria. Members of the let‐7, miR‐200, miR‐30 families, and the miR‐17‐92 clusters are more commonly found to be associated with endometrial receptivity. Experimental studies show that the targets of the differentially expressed microRNAs affect endometrial receptivity, decidualization, and embryo implantation. Free and exosome/microvesicle containing microRNAs have been detected in human and ovine uterine luminal fluid (ULF). They may serve as mediators of embryo–endometrium dialog. Some observations suggest that the microRNAs in ULF may be used as biomarkers in infertility treatment. Conclusion MicroRNAs in endometrium and blastocysts are involved in the implantation process.

Loss of miR-542-3p enhances IGFBP-1 expression in decidualizing human endometrial stromal cells

“…Endometrial expression of miRNAs upon decidualization has been studied in few other species and, as aforementioned, some functional studies have been carried out in rodents192021. Members of three miRNAs families, including Let-7 Family, miR-200 Family, and miR-30 Family, are frequently identified as differentially expressed in these studies22. To the best of our knowledge, the current report is the first to identify that miR-542-3p directly regulates morphological and biological differentiation of HESCs through targeting IGFBP1 expression.…”

Endometrial MicroRNA Signature during the Window of Implantation Changed in Patients with Repeated Implantation Failure

“…[10] miRNAs play a role in some biological processes, such as cellular differentiation, proliferation, and apoptosis, which are involved in implantation. [111213] Therefore, several studies have been conducted to explore their role in endometrial receptivity. The miRNA expression profiles in human endometrium at different phases have been previously investigated.…”

MiR‐27a‐3p and miR‐124‐3p, upregulated in endometrium and serum from women affected by Chronic Endometritis, are new potential molecular markers of endometrial receptivity

“…14 Certainly, the more reliable diagnostic method is fluid hysteroscopy that allows direct observation of macroscopic endometrial alterations and the examination of an endometrial specimen. 20,21 MiRNAs, small non-coding protein RNAs, play an important role in post-transcriptional gene regulation: they repress gene expression by targeting specific mRNAs, most commonly in their 3′ untranslated region. 2,16,17 Many of these proteins represent important regulators in the implantation process mediating the adhesion between the trophectoderm and the endometrial luminal epithelium, and their altered regulation in CE could explain the implantation failure in women with the disease.…”