Development and utilization of human decidualization reporter cell line uncovers new modulators of female fertility

Significance

Up to 15% of couples experience infertility. Implantation must occur in order for the pregnancy hormone hCG to be detected, and thus many pregnancies go unrecognized before being lost due to implantation failure. Decidualization is a complex differentiation process during which the uterine lining grows and dramatically changes form in response to ovarian hormone stimulus, and this process is required for successful implantation. By developing and utilizing a new reporter cell line, the present study systematically uncovers more than 4,000 genetic and chemical modulators of the human decidual response in the hopes of catalyzing new treatments for female infertility, subfertility, and recurrent pregnancy loss.

Abstract

Failure of embryo implantation accounts for a significant percentage of female infertility. Exquisitely coordinated molecular programs govern the interaction between the competent blastocyst and the receptive uterus. Decidualization, the rapid proliferation and differentiation of endometrial stromal cells into decidual cells, is required for implantation. Decidualization defects can cause poor placentation, intrauterine growth restriction, and early parturition leading to preterm birth. Decidualization has not yet been systematically studied at the genetic level due to the lack of a suitable high-throughput screening tool. Herein we describe the generation of an immortalized human endometrial stromal cell line that uses yellow fluorescent protein under the control of the prolactin promoter as a quantifiable visual readout of the decidualization response (hESC-PRLY cells). Using this cell line, we performed a genome-wide siRNA library screen, as well as a screen of 910 small molecules, to identify more than 4,000 previously unrecognized genetic and chemical modulators of decidualization. Ontology analysis revealed several groups of decidualization modulators, including many previously unappreciated transcription factors, sensory receptors, growth factors, and kinases. Expression studies of hits revealed that the majority of decidualization modulators are acutely sensitive to ovarian hormone exposure. Gradient treatment of exogenous factors was used to identify EC ₅₀ values of small-molecule hits, as well as verify several growth factor hits identified by the siRNA screen. The high-throughput decidualization reporter cell line and the findings described herein will aid in the development of patient-specific treatments for decidualization-based recurrent pregnancy loss, subfertility, and infertility.