miRNA-149 targets PARP-2 in endometrial epithelial and stromal cells to regulate the trophoblast attachment process

• Published in: Molecular human reproduction 2021-05, Vol.27 (6)
• Main Authors: Soni, Upendra Kumar, Chadchan, Sangappa Basanna, Gupta, Rakesh Kumar, Kumar, Vijay, Kumar Jha, Rajesh
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions - genetics; Animals; Apoptosis; Base Sequence; Binding Sites; Biomarkers; Caspase 8 - biosynthesis; Caspase 8 - genetics; Coculture Techniques; Computer Simulation; Embryo Implantation - physiology; Endometrium - cytology; Endometrium - metabolism; Epithelial Cells - metabolism; Female; Mice; MicroRNAs - genetics; MicroRNAs - metabolism; Poly(ADP-ribose) Polymerases - biosynthesis; Poly(ADP-ribose) Polymerases - genetics; Pregnancy; RNA, Messenger - genetics; RNA, Messenger - metabolism; Stromal Cells - metabolism; Trophoblasts - physiology
• ISSN: 1360-9947; 1460-2407
• DOI: 10.1093/molehr/gaab039

Abstract Embryo implantation is a highly complex process involving many regulatory factors, including several micro RNAs (miRNAs/miRs). One miRNA present in the stromal cells of normal endometrium is miR-149, which targets poly (ADP-ribose) polymerase 2 (PARP-2), a gene involved in endometrial receptivity for trophoblast implantation. However, the precise role of miR-149 in the endometrial receptivity during blastocyst implantation is still unknown. We studied miR-149-dependent PARP-2 regulation during trophoblast attachment to endometrial epithelial cells. Using FISH, we found that miR-149 is expressed in mouse endometrial epithelial and stromal cells at implantation and inter-implantation sites. Endometrial receptivity for embryo implantation and attachment is inhibited by the upregulation of miR-149 in the endometrium. Our RT-PCR analysis revealed downregulation of miR-149 in the implantation region of the uterus during the receptive stage (Day 5, 0500 h, p.c.) in the mouse. Under in-vitro conditions, miR-149 overexpression in human endometrial epithelial cells (hEECs) abrogated the human trophoblastic cells spheroid and mouse blastocyst attachment. Subsequently, miR-149 also regulates transformed human endometrial stromal cell (T-hESCs) decidualization by downregulating PARP-2 and upregulating caspase-8 proteins. Overexpression of miR-149 in hEECs and downregulated PARP-2 protein expression, reconfirming that PARP-2 is a downstream target of miR-149 in endometrial cells as well. miR-149 is also able to alter the expression of caspase-8, another PARP-2 regulator. In conclusion, our data indicate that miR-149 is one of the regulators of endometrial receptivity and decidualization for trophoblast implantation, and it exerts the effects by acting on the downstream targets PARP-2 and caspase-8.