acts downstream of to regulate uterine decidualization via in mice.

Although has been proved to play an important role in uterine decidualization, its regulatory mechanism remains largely unknown. Here, we showed that was highly expressed in the decidual cells and promoted the proliferation of uterine stromal cells and expression of and , which were two well-known differentiation markers for decidualization. Further analysis revealed that might act downstream of and cAMP to regulate the differentiation of uterine stromal cells. Administration of cAMP analog 8-Br-cAMP to siRNA-transfected stromal cells resulted in an obvious increase of expression, whereas PKA inhibitor H89 impeded the induction of elicited by overexpression, indicating that cAMP-PKA signal mediates the regulation of on expression. In uterine stromal cells, knockdown of blocked the cAMP induction of Moreover, siRNA-mediated downregulation of impaired the stimulatory effects of overexpression on the expression of and , whereas constitutive expression of reversed the inhibitory effects of siRNA on stromal differentiation. Meanwhile, might play a vital role in the crosstalk between and Collectively, may act downstream of cAMP-PKA signal to mediate the effects of on the differentiation of uterine stromal cells through targeting .