WNK lysine deficient protein kinase 1 regulates human endometrial stromal cell decidualization, proliferation, and migration in part through mitogen-activated protein kinase 7.

The differentiation of endometrial stromal cells into decidual cells, termed decidualization, is an integral step in the establishment of pregnancy. The mitogen-activated protein kinase homolog, WNK lysine deficient protein kinase 1 (WNK1), is activated downstream of epidermal growth factor receptor during decidualization. Primary human endometrial stromal cells (HESCs) were subjected to small interfering RNA knockdown of WNK1 followed by in vitro decidualization. This abrogated expression of the decidual marker genes, insulin like growth factor binding protein 1 (IGFBP1) and prolactin (PRL), and prevented adoption of decidual cell morphology. Analysis of the WNK1-dependent transcriptome by RNA-Seq demonstrated that WNK1 regulates the expression of 1858 genes during decidualization. Gene ontology and upstream regulator pathway analysis showed that WNK1 regulates cell migration, differentiation, and proliferation. WNK1 was required for many of the gene expression changes that drive decidualization, including the induction of the inflammatory cytokines, C-C motif chemokine ligand 8 (CCL8), interleukin 1 beta (IL1B), and interleukin 15 (IL15), and the repression of transforming growth factor-beta (TGF-beta) pathway genes, including early growth response 2 (EGR2), SMAD family member 3 (SMAD3), integrin subunit alpha 2 (ITGA2), integrin subunit alpha 4 (ITGA4), and integrin subunit beta 3 (ITGB3). In addition to abrogating decidualization, WNK1 knockdown decreased the migration and proliferation of HESCs. Furthermore, mitogen-activated protein kinase 7 (MAPK7), a known downstream target of WNK1, was activated during decidualization in a WNK1-dependent manner. Small interfering RNA knockdown of MAPK7 demonstrated that MAPK7 regulates a subset of WNK1-regulated genes and controls the migration and proliferation of HESCs. These results indicate that WNK1 and MAPK7 promote migration and proliferation during decidualization and regulate the expression of inflammatory cytokines and TGF-beta pathway genes in HESCs.

The Role of Steroid Hormone Receptors in the Establishment of Pregnancy in Rodents.

The ovarian hormones, estrogen and progesterone, and their receptors, the estrogen receptor (ER) and progesterone receptor (PR), orchestrate the complex sequence of events required for uterine receptivity and the establishment of pregnancy. The actions of ER, PR, and other steroid hormone receptors (SHRs) direct the uterus through the processes of implantation and decidualization. Due to the ethical concerns of studying pregnancy in humans, genetically engineered rodent models have facilitated many of the discoveries that have elucidated the molecular events directing early pregnancy. This chapter will cover the conserved structure and function of the SHRs. ER and PR will be highlighted for their pivotal roles in uterine receptivity, implantation, and decidualization. The dynamic regulation of ER and PR expression and activity throughout the estrous cycle and early pregnancy, and the importance of SHRs in coordinating paracrine signaling between the endometrial compartments will also be explored. Finally, the roles of androgen receptor (AR) and glucocorticoid receptor (GR) in the establishment of pregnancy will be discussed.

Absence of Activation of DNA Repair Genes and Excellent Efficacy of Phosphaplatins against Human Ovarian Cancers: Implications To Treat Resistant Cancers.

Phosphaplatins, platinum(II) and platinum(IV) complexes coordinated to a pyrophosphate moiety, exhibit excellent antitumor activities against a variety of cancers. To determine whether phosphaplatins trigger resistance to treatment by engaging DNA damage repair genes, a yeast genome-wide fitness assay was used. Treatment of yeast cells with pyrodach-2 (D2) or pyrodach-4 (D4) revealed no particular sensitivity to nucleotide excision repair, homologous recombination repair, or postreplication repair when compared with platin control compounds. Also, TNF receptor superfamily member 6 (FAS) protein was overexpressed in phosphaplatin-treated ovarian tumor cells, and platinum colocalized with FAS protein in lipid rafts. An overactivation of sphingomyelinase (ASMase) was noted in the treated cells, indicating participation of an extrinsic apoptotic mechanism due to increased ceramide release. Our results indicate that DNA is not the target of phosphaplatins and accordingly, that phosphaplatins might not cause resistance to treatment. Activation of ASMase and FAS along with the colocalization of platinum with FAS in lipid rafts support an extrinsic apoptotic signaling mechanism that is mediated by phosphaplatins.