Development of a Three-Dimensional Endometrial Model to Examine Factors Affecting Endometrial Function

Endometriosis, a reproductive disease affecting one in ten women, is characterized by debilitating pain, excessive menstrual bleeding, and infertility. Elevated levels of certain proteins, such as pro-inflammatory cytokines and SIRT1, are seen in endometrial tissue from endometriosis patients and are thought to be contributing factors to infertility by negatively affecting the endometrium's ability to decidualize prior to implantation. Given the inherent limitations of studying the human endometrium in vivo, there is a need to develop an in vitro model to study the endometrium and its interaction with trophoblast cells that will form the placenta. These studies aimed to develop one part of a three-dimensional model of the endometrium using a semi-synthetic, derivatized collagen matrix, GelMA, and endometrial stromal cells. An essential function of endometrial cells is decidualization, a conversion from mesenchymal-like to epithelial-like cells reflected by a significant change in gene expression, including a marked increase in prolactin (PRL) production. Without decidualization, a mammalian pregnancy cannot be established. Optimization of the 3-D model involved RT-qPCR to measure PRL gene expression with or without combined treatment with decidualization factors (estradiol (10E-8 M), medroxyprogesterone (10E-6 M), and cAMP (10E-6 M)). We also compared that response to stromal cells on plastic in 2-D culture. Decidualization was successfully induced in the 3-D culture conditions in a manner similar to that seen on plastic (and in vivo). The development of this model opens the door for future investigations aimed at better understanding the molecular functions of the endometrium and the etiologies underlying idiopathic infertility, as well as helping discover novel pharmacological targets to treat infertility in women with endometriosis.