Gaq-PKD/PKCμ regulates the IkB transcription to limit the NF-kB mediated inflammatory response essential for early pregnancy

Decidualization, denoting the transformation of endometrial stromal cells into specialized decidual cells, is a prerequisite for normal embryo implantation and a successful pregnancy in human. Here we demonstrated that knockout of Gaq lead to an aberrantly enhanced inflammatory state during decidualization. Furthermore, we showed that deficiency of Gaq resulted in over-activation of nuclear factor (NF)-{kappa}B signaling, due to the decreased expression of NF{kappa}BIA, which encode the I{kappa}B protein and is the negative regulator for NF{kappa}B. Mechanistically, Gaq deficiency decreased the PKD/PKC phosphorylation levels, so leading to attenuated HDAC5 phosphorylation and thus its nuclear export. Aberrantly high level of nuclear HADC5 retarded histone acetylation to inhibit NF{kappa}BIA transcription during decidualization. Consistently, pharmacological activation of the PKD/PKC or inhibition of the HDAC5 signaling restored the inflammatory state and proper decidual response. Finally, we disclosed that over-active inflammatory state in Gaq deficient decidua deferred the blastocyst hatching and adhesion in vitro, and the decidual expression of Gq was significantly lower in women with recurrent pregnancy loss compared with normal pregnancy. In brief, we showed here that Gq as a key regulator of the inflammatory cytokines expression and decidual homeostasis in response to differentiation cues, which is required for successful implantation and early pregnancy.