Context Poor uterine receptivity is one major factor leading to pregnancy loss and infertility. Understanding the molecular events governing successful implantation is hence critical in combating infertility. Objective To define Progesterone Receptor (PGR)-regulated molecular mechanisms and epithelial roles in receptivity. Design RNA-sequencing and PGR-ChIP-seq were conducted in parallel to identify PGR-regulated pathways during the Window of implantation (WOI) in endometrium of fertile women. Setting Endometrial biopsies from the proliferative and mid-secretory phases were analyzed. Patients or Other Participants Participants were fertile, reproductive aged (18–37 years) women with normal cycle length, and without any history of dysmenorrhea, infertility, or irregular cycles. In total, 42 endometrial biopsies obtained from 42 women were analyzed in this study. Interventions There were no interventions during this study. Main Outcome Measures Here we measured the alterations in gene expression and PGR occupancy in the genome during the WOI, based on the hypothesis that PGR binds uterine chromatin cycle dependently to regulate genes involved in uterine cell differentiation and function. Results 653 genes were identified with regulated PGR binding and differential expression during the WOI. These were involved in regulating inflammatory response, xenobiotic metabolism, epithelial mesenchymal transition, cell death, interleukin/Signal Transducer And Activator Of Transcription (STAT) signaling, estrogen response, and Mammalian target of rapamycin complex 1 (MTORC1) response. Transcriptome of the epithelium identified 3052 differentially expressed genes, of which 658 were uniquely regulated. Transcription factors Interferon Regulatory Factor 8 (IRF8) and Myocyte Enhancer Factor 2C (MEF2C) were found to be regulated in the epithelium during the WOI at the protein level, suggesting potentially important functions that are previously unrecognized. Conclusion PGR binds the genomic regions of genes regulating critical processes in uterine receptivity and function.

Platinum-based anticancer drugs, including cisplatin and carboplatin, have been cornerstones in the treatment of solid tumors. We report here that these DNA-damaging agents, particularly cisplatin, induce apoptosis through plasma membrane disruption, triggering FAS death receptor via mitochondrial (intrinsic) pathways. Our objectives were to: quantify the composition of membrane metabolites; and determine the potential involvement of acid sphingomyelinase (ASMase) in the FAS-mediated apoptosis in ovarian cancer after cisplatin treatment. The resulting analysis revealed enhanced apoptosis as measured by: increased phosphocholine, and glycerophosphocholine; elevated cellular energetics; and phosphocreatine and nucleoside triphosphate concentrations. The plasma membrane alterations were accompanied by increased ASMase activity, leading to the upregulation of FAS, FASL and related pro-apoptotic BAX and PUMA genes. Moreover FAS, FASL, BAX, PUMA, CASPASE-3 and -9 proteins were upregulated. Our findings implicate ASMase activity and the intrinsic pathways in cisplatin-mediated membrane demise, and contribute to our understanding of the mechanisms by which ovarian tumors may become resistant to cisplatin.

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.

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.

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.