During the menstrual cycle, the endometrium undergoes cyclic changes of cellular proliferation, differentiation, and death, an essential preparation of the endometrium for its interaction with the implanting embryo. In particular, the differentiation of endometrial stromal cells, named decidualization, ensures the formation of a proper feto-maternal interface for a regulated trophoblast invasion and correct placental orientation and growth. Interestingly, autophagy, an intracellular degradation process of great importance for the maintenance of cellular homeostasis, plays an important role in cell proliferation, differentiation, and growth. In the endometrium, increased detection of autophagy markers correlates with the progression of the menstrual cycle. However, until now, it was unknown whether autophagy contributes to the proper function of the endometrium. In this study, we show that autophagy is increased during in vitro decidualization of human endometrial stromal cells. Furthermore, we demonstrate that the knockdowns of two important autophagy-related (ATG) proteins, ATG7 and ATG5, impaired decidualization, confirming a positive role of these proteins and of autophagy for the correct decidualization of human endometrial stromal cells. In conclusion, in this work, we describe a previously unknown functional connection between autophagy and endometrial physiology.

Progesterone receptor and estrogen receptor participate in growth and differentiation of the different rat decidual regions. Steroid hormone receptor antagonists were used to study steroid regulation of decidualization. Here we describe a suppressive interaction between progesterone receptor (onapristone) and estrogen receptor (ICI182780) antagonists and their relation to a rescue phenomenon with concomitant regulation of Hand2, Bmp2 and p-ERK1/2 during the early decidualization steps. Phenotypes of decidua development produced by antagonist treatments were characterized by morphology, proliferation, differentiation, angiogenesis and expression of signaling molecules. We found that suppression of progesterone receptor activity by onapristone treatment resulted in resorption of the implantation sites with concomitant decrease in progesterone and estrogen receptors, PCNA, KI67 antigen, DESMIN, CCND3, CX43, Prl8a2, and signaling players such as transcription factor Hand2, Bmp2 mRNAs and p-ERK1/2. Moreover, FGF-2 and Vegfa increased as a consequence of onapristone treatment. Implantation sites from antagonist of estrogen receptor treated rats developed all decidual regions, but showed an anomalous blood vessel formation at the mesometrial part of the decidua. The deleterious effect of onapristone was partially counteracted by the impairment of estrogen receptor activity with rescue of expression levels of hormone steroid receptors, proliferation and differentiation markers, and the induction of a probably compensatory increase in signaling molecules Hand2, Bmp2 and ERK1/2 activation compared to oil treated controls. This novel drug interaction during decidualization could be applied to pathological endometrial cell proliferation processes to improve therapies using steroid hormone receptor targets.

Cell line establishment of somatic cells is a valuable resource to preserve genetic material of rare, difficult‐to‐find, endangered and giant species like Jaguar (Panthera onca), the largest South American felid. This unit focuses on the isolation and culture of fibroblasts from Jaguar skin and muscle biopsies, and ear cartilage dissection immediately after death to preserve one of the several endangered species in this biome. These culture techniques enabled us to contribute 570 samples from 45 autochthonous and endangered species, including Jaguar. The fibroblasts obtained are a part of the Genetic Bank of Buenos Aires Zoo with the 6700 samples, including tissues such as muscle, ovarian, testicular, blood, fibroblast cultures, sperm, hair, and fluids and cells from 450 individuals of 87 different species. © 2016 by John Wiley & Sons, Inc.

The differentiation of endometrial stromal cells (ESC), named decidualization, is essential to regulate trophoblast invasion and to support pregnancy establishment and progression. Decidualization follows ESC proliferation and it has been described that cell cycle arrest contributes to a proper decidualization. Interestingly, resveratrol, a natural compound derived from grapes with antioxidant properties, has been widely studied in relation to endometrial health. However, little is known about the effect of resveratrol supplementation during decidualization. Therefore, in this study we evaluate the effect of resveratrol supplementation during decidualization. We used primary and immortalized human ESC and we decidualized them in vitro with a decidualization cocktail containing medroxyprogesterone acetate, estradiol and 8-Bromo-cyclic AMP. Pre-decidualized cells were further treated with the decidualization cocktail supplemented with resveratrol. Our results show that resveratrol supplementation increased, in a dose-dependent manner, the expression levels of prolactin and IGFBP1 (RT-PCR and ELISA), indicating an enhanced in vitro decidualization of human ESC. This enhanced decidualization was accompanied by a decrease in cell proliferation (crystal violet and CellTiter proliferation assay) and by changes in the mRNA levels of key cell cycle regulators (RT-PCR). Furthermore, resveratrol supplementation seemed to enhance decidualization by reinforcing the effect of the decidualization cocktail. We believe that resveratrol could to be an effective supplementation to reinforce hormone action during human ESC decidualization and that further insights into resveratrol action and its interaction with estradiol and progesterone signaling pathways could facilitate the identification of new therapeutic strategies for the improvement of women’s health.

Although non-genomic steroid receptor pathways have been studied over the past decade, little is known about the direct gene expression changes that take place as a consequence of their activation. Progesterone controls proliferation of rat endometrial stromal cells during the peri-implantation phase of pregnancy. We showed that picomolar concentration of progestin R5020 mimics this control in UIII endometrial stromal cells via ERK1-2 and AKT activation mediated by interaction of Progesterone Receptor (PR) with Estrogen Receptor beta (ERb) and without transcriptional activity of endogenous PR and ER. Here we identify early downstream targets of cytoplasmic PR signaling and their possible role in endometrial stromal cell proliferation. Microarray analysis of global gene expression changes in UIII cells treated for 45 min with progestin identified 97 up- and 341 down-regulated genes. The most over-represented molecular functions were transcription factors and regulatory factors associated with cell proliferation and cell cycle, a large fraction of which were repressors down-regulated by hormone. Further analysis verified that progestins regulate Ccnd1, JunD, Usf1, Gfi1, Cyr61, and Cdkn1b through PR-mediated activation of ligand-free ER, ERK1-2 or AKT, in the absence of genomic PR binding. ChIP experiments show that progestin promoted the interaction of USF1 with the proximal promoter of the Cdc2 gene. Usf1 knockdown abolished Cdc2 progestin-dependent transcriptional regulation and cell proliferation, which also blocked Cdc2 knockdown. We conclude that progestin-induced proliferation of endometrial stromal cells is mediated by ERK1-2 and AKT dependent early regulation of USF1, which directly induces Cdc2. To our knowledge, this is the first description of early target genes of progestin-activated classical PR via crosstalk with protein kinases and independently of hormone receptor binding to the genomic targets.