G-2146

Unraveling Endometrial MicroRNA Dysregulation: Bioinformatic and Experimental Insights into Recurrent Implantation Failure

 Rahim Rostami ¹ ℗, Shirin Salehi ², Massoumeh Rotami ³, Jamileh Jahanbakhsh ⁴, Soudabeh Fallah ⁵ ©   

 
Abstract

Introduction: Currently, a diagnostic tool with high specificity for impaired endometrial receptivity, which may lead to implantation failure, is yet to be developed. Our aim is to assess the different endometrial microRNA (miRNA) signatures for impaired endometrial receptivity by microarray analysis. The potential benefits of our research could lead to the development of a highly specific diagnostic tool, offering new insights and potential solutions for implantation failure. Methods and Materials: Our research involved a comprehensive process. We recruited a total of 50 repeated implantation failure (RIF) patients and 50 infertile patients who successfully conceived and delivered after one embryo transfer attempt, forming the RIF and control groups, respectively. Endometrial specimens from the window of implantation (WOI) were collected from these two groups. We used GSE71332 and GSE121219 to identify the key miRNAs in endometrial samples using R software with Multimir and Biomart packages. The GSE71331 contains five control and 7 RIF samples, and GSE121219 contains 10 control and 8 RIF samples. The quantitative PCR (qPCR) of miRNAs was conducted on the samples from the RIF and control groups, respectively. Comparative, functional, and network analyses were performed for the microarray results, ensuring a thorough investigation. Results: In comparison to the control group, the expression levels of six specific miRNAs in the RIF group demonstrated significant up- or down-regulation (at least 1.5 and 1.5 fold) as assessed by qPCR analysis. Notably, the dysregulated miRNAs were associated with critical functional sets, including the miR-29 family, human embryonic stem cell regulation, epithelial-mesenchymal transition (EMT), and miRNA tumor suppressors, as identified through microRNA annotation tools. Network regulatory analysis unveiled 176 miRNA-mRNA interactions, with the top six core miRNAs being hsa-miR-191-5p, hsa-miR-27a-3p, hsa-miR-29a-3p, hsa-miR-29b-3p, hsa-miR-29c-3p, and hsa-miR-767-5p. The upregulation of hsa-miR-191-5p in the culture media of implanted human embryos on day five post-fertilization highlights its potential role in facilitating successful implantation. This miRNA modulates genes critical to the implantation window, such as IGF2BP-1 and IGF2R, both of which are vital for embryo attachment and subsequent development. Hsa-miR-27a-3p interacts with various protein-coding genes and long non-coding RNAs, significantly influencing metabolic pathways and inflammation. In pregnancy, it enhances endometrial receptivity, promoting a favorable environment for embryo implantation. The hsa-miR-29 family (hsa-miR-29a-3p, hsa-miR-29b-3p, hsa-miR-29c-3p) is involved in extracellular matrix remodeling, essential for effective implantation. Dysregulation in this family can lead to fibrosis and altered immune responses, jeopardizing implantation success. Meanwhile, hsa-miR-767-5p, although linked to oncogenic processes, has an unclear role in pregnancy and implantation failure, particularly regarding trophoblast invasion. Conclusion and Discussion: This study identifies a marked alteration in the expression profiles of specific miRNAs within the endometrium of patients with RIF. These dysregulated miRNAs are likely implicated in the mechanisms underlying compromised endometrial receptivity.

Keywords: Recurrent Implantation Failure, Female infertility, miRNAs, Bioinformatic