E-Poster Presentation ESA-SRB-ANZBMS 2021

miR-23b-3p is involved in regulating human endometrial receptivity implying a role in implantation (#62)

Siena Barton 1 2 , Wei Zhou 1 2 , Leilani Santos 1 2 , Swati Varshney 3 , Evdokia Dimitriadis 1 2
  1. Department of Obstetrics and Gynaecology, University of Melbourne , Parkville, VIC, Australia
  2. Gynaecology Research Centre, The Royal Women’s Hospital, Parkville, VIC, Australia
  3. Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Molecular Science & Biotechnology Institute, University of Melbourne , Parkville, VIC, Australia

The human endometrium undergoes dramatic remodelling and molecular changes throughout the menstrual cycle that are essential for successful blastocyst attachment in the receptive, mid-secretory phase. microRNA (miR) levels are altered in the receptive phase and are thought to play a role in blastocyst implantation. miR-23b-3p is known to be differentially expressed in the endometrium of women with normal fertility compared to infertility. We aimed to investigate the expression of miR-23b-3p in human endometrium across the menstrual cycle, its function, and mechanisms of action in receptivity. Using qPCR, we demonstrated that miR-23b-3p was significantly upregulated in the fertile endometrium of the mid-secretory (receptive) compared to proliferative (non-receptive) phase (p<0.05). miR-23b-3p was identified in both the epithelium and stroma, with highest expression found in the endometrial epithelium during the mid-secretory phase. Ishikawa cells (endometrial epithelial cell line) and primary endometrial epithelial cells (EEC) were used to determine the effect of miR-23b-3p overexpression on adhesive capacity to trophectodermal spheroids. Overexpression of miR-23b-3p improved the adhesive capacity of endometrial epithelial cells (p<0.05). miR-23b-3p predicted mRNA targets (n=11) were investigated using qPCR and MET, SFRP4 and ACADSB were significantly downregulated in miR-23b-3p transfected EEC compared to scramble control (p<0.05). Mass spectrometry analysis was performed comparing Ishikawa cells overexpressing miR-23b-3p and control. 59 proteins were differentially expressed (p<0.05). STRING network analysis revealed significant protein interactions (protein-protein enrichment p-value<0.05), with functional enrichment in focal adhesion, integrin-mediated cell adhesion, cell-substrate junction pathways. Of the 59 differentially expressed proteins, 9 were predicted miR-23b-3p targets in the miRWalk database. Our data demonstrated that miR-23b-3p is likely a critical regulator of epithelial adhesion and endometrial receptivity. miR-23b-3p could serve as a diagnostic to identify which women may benefit from personalised therapeutics, specifically that target miR-23b-3p to improve receptivity, implantation potential and the establishment of pregnancy.