Abstract: Abstract: Objective To explore the expression and function of miR-125b, miR-30b and miR-424 in endometrial cells. Methods Human endometrial samples were obtained in natural cycles and stimulating cycles. Endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs) were isolated and confirmed by immunofluorescence. The expressions of miR-125b, miR-30b and miR-424 were detected by real-time PCR. Results The expression levels of miR-125b, miR- 30b and miR-424 were higher in proliferative phase in ESCs than those in EECs. And in EECs, the expression levels of miR-125b, miR-30b and miR-424 were significantly up-regulated in secretory phase than in proliferative phase, while it was stable in ESCs. In addition, the expressions of miR-125b in EECs and miR-30b were increased in ESCs in women with elevated progesterone on the day of HCG administration than those of the control. The target genes of miR-125b, miR-30b and miR- 424 mainly participated in cell migration and motion, cell- cell adherens junction and Wnt signaling pathway. Conclusion miR-125b, miR-30b and miR-424 were differently expressed in endometrial cells in different phases, and may participate in regulation of endometrial receptivity.

Key words: microRNAs, endometrium, progesterone, epithelial cells, stromal cells, miR- 125b, miR-30b, miR-424, endometrial receptivity