Inhibition of TPPP3 attenuates β-catenin/NF-κB/COX-2 signaling in endometrial stromal cells and impairs decidualization

Abstract

Embryo implantation and decidualization are critical events that occur during early pregnancy. Decidualization is synchronized by the crosstalk of progesterone and the cAMP signaling pathway. Previously, we confirmed the role of TPPP3 during embryo implantation in mice, but the underlying role and mechanism of TPPP3 in decidualization has not yet been understood. The current study was aimed to investigate the role of TPPP3 in decidualizationin vivoandin vitro. Forin vivoexperiments, decidual reaction was artificially induced in the uteri of BALB/c mice. TPPP3 was found to be highly expressed during decidualization, whereas in the uteri receiving TPPP3 siRNA, decidualization was suppressed and the expression of β-catenin and decidual marker prolactin was reduced. In human endometrium, TPPP3 protein was found to be predominantly expressed in the mid-secretory phase (LH+7). In the primary culture of human endometrial stromal cells (hESCs), TPPP3 siRNA knockdown inhibited stromal-to-decidual cell transition and decreased the expression of the decidualization markers prolactin andIGFBP-1. Immunofluorescence and immunoblotting experiments revealed that TPPP3 siRNA knockdown suppressed the expression of β-catenin, NF-κB and COX-2 in hESCs during decidualization. TPPP3 inhibition also decreased NF-kB nuclear accumulation in hESCs and suppressed NF-κB transcriptional promoter activity. COX-2 expression was significantly decreased in the presence of a selective NF-kB inhibitor (QNZ) implicating that NF-kB is involved in COX-2 expression in hESCs undergoing decidualization. TUNEL assay and FACS analysis revealed that TPPP3 knockdown induced apoptosis and caused loss of mitochondrial membrane potential in hESCs. The study suggested that TPPP3 plays a significant role in decidualization and its inhibition leads to the suppression of β-catenin/NF-κB/COX-2 signaling along with the induction of mitochondria-dependent apoptosis.

Administration of a herbal formulation enhanced blastocyst implantation via IκB activation in mouse endometrium

“…NF-κB is critical for the induction of both iNOS and COX-2 in various cells including gingival fibroblasts and endometrial stromal cells [ 40 , 41 ], and the expression of pro-inflammatory cytokines in uterus throughout the estrous cycle is necessary for embryo receptivity and successful blastocyst implantation [ 42 ]. Decidualization describes a series of changes in uterus during the early stages of pregnancy that are necessary for placenta formation and fetal development [ 43 , 44 ].…”

Administration of Herb Formulation Enhanced Blastocyst Implantation via Iκb Activation in Mouse Endometrium

“…NF-κB induces COX-2 expression in various cells including gingival broblasts and endometrial stromal cells [61][62][63], and the expression of pro-in ammatory cytokines in uterus throughout the estrous cycle is necessary for embryo receptivity and successful blastocyst implantation [64]. NF-κB dimers are sequestered in the cytoplasm by binding with IκBα and hence inactivated [65].…”

Administration of a herbal formulation enhanced blastocyst implantation via IκB activation in mouse endometrium

“…However, how BCB regulates IκBα activation in endometrium remains unknown. NF-κB is critical for the induction of both iNOS and COX-2 in various cells including gingival broblasts and endometrial stromal cells [40,41], and the expression of pro-inflammatory cytokines in uterus throughout the estrous cycle is necessary for embryo receptivity and successful blastocyst implantation [42]. Decidualization describes a series of changes in uterus during the early stages of pregnancy that are necessary for placenta formation and fetal development [43,44].…”