Notch 1 signaling pathway effect on implantation competency

Abstract

Objective: To investigate the relationship between the Notch 1 signaling pathway and the embryo implantation rate.

Design: Mouse embryos were cultured in vitro, and implantation competency was quantified.

Setting: Tertiary fertility center of a university teaching hospital.

Animal(s): Outbred ICR strain mouse embryos.

Intervention(s): The expression of Notch 1 was altered by adding a γ-secretase inhibitor to the culture medium. We quantified the consequent effect on embryo implantation.

Main outcome measure(s): We measured the messenger RNA level of Notch 1 gene at different embryonic stages, embryo implantation rate under different culture conditions, the amount of Notch 1, and related implantation competency.

Result(s): Quantitative polymerase chain reaction showed that the expression of Notch 1 increased during the implantation window. Adding γ-secretase inhibitor in the culture medium decreased the percentage of blastocysts in a dose-dependent manner. A Matrigel invasion assay showed that the competency of implantation required adequate expression of Notch 1 intracellular domain.

Conclusion(s): Expression of Notch 1 at the proper time is required for the competency of embryo implantation; this effect is mediated through regulation of Notch 1 intracellular domain expression.