Expression and Regulation of a Novel Decidual Cells-Derived Estrogen Target during Decidualization.

During decidualization in rodents, uterine stromal cells undergo extensive reprogramming to differentiate into distinct cell types, forming primary decidual zones (PDZs), secondary decidual zones (SDZs), and layers of undifferentiated stromal cells. The formation of secondary decidual zones is accompanied by extensive angiogenesis. During early pregnancy, besides ovarian estrogen, de novo synthesis of estrogen in the uterus is essential for the progress of decidualization. However, the molecular mechanisms are not fully understood. Studies have shown that Cystatin B () is highly expressed in the decidual tissue of the uterus, but the regulation and mechanism of in the process of decidualization have not been reported. Our results showed that was highly expressed in mouse decidua and artificially induced deciduoma via in situ hybridization and immunofluorescence. Estrogen stimulates the expression of through the Estrogen receptor (ER)α. Moreover, in situ synthesis of estrogen in the uterus during decidualization regulates the expression of . Silencing the expression of affects the migration ability of stromal cells. Knockdown by siRNA significantly inhibits the expression of , a marker for mouse decidualization. Our study identifies a novel estrogen target, , during decidualization and reveals that may play a pivotal role in angiogenesis during mouse decidualization via the .