Construction of 3D Endometrium System for the Receptivity

초록

Introduction: Endometrium (EM) is a multi-layered organ, consisting of a functional and basal layer that covers the myometrium. It is known that preprogrammed growth factors and adhesion molecules have been activated by the endometrium or embryo and it induces to form of a receptive endometrium, decidua. Several studies were conducted to elucidate the regulators of the transition, however, embryo-endometrium crosstalk is difcult to accurately observe in the 2D environment. In this study, we investigate the optimal 3D endometrium in vitro-producing condition by comparing the cell and alginate ratio and EM viability. Methods: Endometrium cells (3.75x10^7) from nine-week-old female C57BL/6 were cultured and further mixed with or without 3D gel made of alginate. The alginate and endometrial cells were mixed at ratios of 1:1, 2:1, and 3:1 and cultured for up to nine days. Cell viability was analyzed by the WST method to defne cell survival rate. Attachment and invasion of mouse blastocyst were analyzed by expression of Oct4. Results: Embedded endometrial cells survive up to nine days and cell viability of each alginate-EM mixture was higher in 1:1 and 2:1 with no signifcant diference. The diferent ratio of the alginate-EM mixture results in diferent stifness, which critically afects the survival and invasion of the embryo. The ratio of the alginate-EM mixture at 1:1 and 2:1 successfully supports the survival and invasion of the embryos, however, not at 3:1. Conclusion: Taken together, this study demonstrated that a 3D endometrial system could be applied as artifcial endometrium for the study of embryo-endometrium crosstalk. Further studies are necessary to fnd the expression and secreting of factors during endometrial-embryonic interactions in a 3D culture system (2020R1F1A1076286 and 2021R1F1A1060218).