RICTOR Prevents Decidualization Disorder in Women With Advanced Maternal Age via Regulating FoxO1 Nuclear Export.

Miscarriage and abnormal embryonic development in women of advanced maternal age (AMA) are often associated with impaired decidualization. mTORC2 is an evolutionarily conserved protein kinase. As a core component of mTORC2, RICTOR has been implicated in nutrient sensing and is closely linked to implantation disorders; however, its role in regulating age-related decidualization disorders remains unreported. In this study, we identified pronounced decidualization defects in AMA foster mice, accompanied by a significant reduction in RICTOR in the decidual tissues of AMA women. Uterine-specific genetic deletion of Rictor in mice resulted in pregnancy loss and impaired decidualization. Notably, Rictor knockdown led to attenuated Akt3-FoxO1 signaling and impaired nuclear export of FoxO1. Molecular and histological analyses demonstrated that the specific RICTOR activator MHY1485 effectively rescued decidualization defects in vivo and in vitro. These findings indicate that RICTOR plays an essential role in the aging decidual microenvironment and may serve as a potential biomarker for uterine stromal cell decidualization. Furthermore, therapeutic activation of RICTOR represents a promising strategy to counteract senescent decidual impairment in AMA women and improve pregnancy outcomes.