The dynamic change of microRNA expression profile in endometrium and peripheral blood during the peri-implantation window

Previous studies have shown that microRNAs (miRNAs) play a crucial role in human embryo implantation by regulating the expression of genes involved in the process. While dynamic changes in plasma miRNA during the peri-implantation period have been established, systematic and comprehensive studies on miRNA expression changes in both endometrial tissue and blood during this period are lacking. A total of 62 subjects, including 62 endometrial tissue samples and 62 paired peripheral blood samples, were collected from participants undergoing hormone treatment cycles between day P+3 to P+7. Next-generation sequencing (NGS) assay was used to profile miRNA expression levels, and the results were annotated using miRBase. To identify the dynamic differentially expressed (DE) miRNAs between day P+3 to P+7, we compared the following group pairs: P+3 and P+4, P+4 and P+5, P+5 and P+6, and P+6 and P+7. We then perform functional miRNA-target interaction (MTI) and pathway enrichment analyses to understand the biological functions of dynamic DE miRNAs. We identified 76 and 48 dynamic DE miRNAs in endometrial tissue and peripheral blood samples, respectively. Functional MTI and pathway enrichment analyses revealed that these DE miRNAs influence numerous biological pathways and functions related to implantation, such as cell senescence, cell growth, apoptosis, focal adhesion, autophagy, platelet activation and signaling. Although only 10 DE miRNAs overlapped between endometrial tissue and peripheral blood, 7 of these showed consistent dynamic expression changes. Further analysis revealed a high similarity in the biological pathways and functions involving the target genes of DE miRNAs in both endometrial tissue and peripheral blood. 76 and 48 dynamic DE miRNAs were identified in endometrial tissue and peripheral blood samples, respectively. These miRNAs influence numerous biological pathways and functions related to implantation. Overall design: miRNA-seq profiling of 62 endometrial tissue samples and 62 peripheral blood samples at day P+3 to P+7 after progesterone treatment