NK cells: shielding senescence homeostasis in the decidua during early pregnancy

Decidualization, the transformation of endometrial stromal cells into specialized decidual cells, is essential for embryo implantation and pregnancy maintenance. This process involves immune cell infiltration, especially decidual natural killer (dNK) cells, which regulate immune responses and support tissue remodeling. Recent findings suggest that cellular senescence during decidualization is not just a byproduct but plays a functional role in enhancing uterine receptivity. However, excessive senescence leads to complications like recurrent pregnancy loss. dNK cells help maintain decidual homeostasis by clearing senescent cells, preventing their harmful accumulation. The balance between dNK activity and decidual stromal cell (DSC) senescence is crucial for successful implantation and pregnancy outcomes. Disruption of this balance may contribute to pathological conditions. This review delves into the pivotal roles of dNK cells in decidual senescence regulation and discusses therapeutic strategies targeting senescence to improve pregnancy outcomes, and new approaches for treating reproductive disorders.