AQP2 is regulated by estradiol in human endometrium and is associated with spheroid attachment in vitro

Research progress of endometrial receptivity in patients with polycystic ovary syndrome: a systematic review

Polycystic ovary syndrome (PCOS) is a neuroendocrine heterogeneous disease that frequently occurs in women of reproductive age, causing serious damage to the fertility, quality of life, and physical and mental health of patients. The current studies have proved that satisfactory endometrial receptivity is one of the conditions that must be met during the process of spermatovum position, adhesion and invasion, as well as the subsequent blastocyst division and embryo development. Women with PCOS may suffer a series of pathological processes such as changes in the expression levels of hormones and related receptors, imbalances in the proportion of miscellaneous cytokines, insulin resistance, low-grade chronic inflammation and endometrial morphological changes, which will damage endometrial receptivity from various aspects and obstruct fertilized egg nidation and embryonic development, thus causing adverse reproductive health events including infertility and abortion. This article reviews the research progress about characteristics and related influencing factors of endometrial receptivity in PCOS patients.

The In Vitro Effect of Steroid Hormones, Arachidonic Acid, and Kinases Inhibitors on Aquaporin 1, 2, 5, and 7 Gene Expression in the Porcine Uterine Luminal Epithelial Cells during the Estrous Cycle

Aquaporins (AQPs) are integral membrane proteins, which play an important role in water homeostasis in the uterus. According to the literature, the expression of aquaporins in reproductive structures depends on the local hormonal milieu. The current study investigated the effect of selected PKA kinase inhibitor H89 and MAPK kinase inhibitor PD98059, on the expression of AQP1, 2, 5, and 7, and steroid hormones (E₂), progesterone (P₄), and arachidonic acid (AA) in the porcine endometrium on days 18–20 and 2–4 of the estrous cycle (the follicular phase where estrogen and follicle-stimulating hormone (FSH) are secreted increasingly in preparation for estrus and the luteal phase where the ovarian follicles begin the process of luteinization with the formation of the corpus luteum and progesterone secretion, respectively). The luminal epithelial cells were incubated in vitro in the presence of the aforementioned factors. The expression of mRNA was determined by the quantitative real-time PCR technique. In general, in Experiment 1, steroid hormones significantly increased expression of AQP1, 2, and 5 while arachidonic acid increased expression of AQP2 and AQP7. On the other hand, MAPK kinase inhibitor significantly decreased the expression of AQP1 and 5. In Experiment 2, E₂, P₄, or AA combined with kinase inhibitors differentially affected on AQPs expression. E₂ in combination with PKA inhibitor significantly decreased expression of AQP1 but E₂ or P₄ combined with this inhibitor increased the expression of AQP5 and 7. On the contrary, E₂ with PD98059 significantly increased AQP5 and AQP7 expression. Progesterone in combination with MAPK kinase inhibitor significantly downregulated the expression of AQP5 and upregulated AQP7. Arachidonic acid mixed with H89 or PD98059 caused a decrease in the expression of AQP5 and an increase of AQP7. The obtained results indicate that estradiol, progesterone, and arachidonic acid through PKA and MAPK signaling pathways regulate the expression of AQP1 and AQP5 in the porcine luminal epithelial cells in the periovulatory period.

Aquaporin 3 Expression in Endometrioid Carcinoma of the Uterine Body Correlated With Early Stage and Lower Grade

Aquaporins (AQPs) are a family of transmembrane water channel proteins distributed in various human tissues. Recent studies revealed that AQPs play important roles in cancer biology. Few studies have documented the relationship between the prognosis, stage, and histological grade of uterine endometrioid carcinoma, with AQP expression. Hence, the present study aimed to investigate this relationship between uterine endometrioid carcinoma and AQP expression. We retrospectively reviewed records of the patients who underwent surgery for uterine body cancer between 1990 and 2010 at the National Defense Medical College Hospital, Saitama, Japan. In 241 cases of endometrioid carcinoma, we immunohistochemically examined the expression of AQP 1, 2, 3, 4, and 5, and their relationship with clinicopathological parameters and the patients' prognosis. We investigated the relationship between the clinicopathological parameters and AQP3 expression, and found that as the FIGO stage and histological grade progressed, the percentage of AQP3 expression tends to decrease. Furthermore, we analyzed progression-free survival/overall survival (PFS/OS) using the log-rank test, and found that the AQP3-positive group had a better prognosis than AQP3-negative group (PFS: P < 0.001, OS: P = 0.002, respectively). Using Cox's univariate proportional hazard model, we revealed that AQP3 had a low hazard ratio. However, according to Cox's multivariate proportional hazard model, AQP3 was not an independent prognostic factor. Among the endometrioid carcinoma patients, the AQP3-positive group was associated with early stage and lower grade compared to the AQP3-negative group. Therefore, AQP3 has the potential to serve as a predictor of prognosis, although further investigation is necessary to elucidate the biological mechanism of AQP3 in endometrioid carcinoma.

Pinopodes: Recent advancements, current perspectives, and future directions

Successful embryo implantation is a complex and highly regulated process involving precise synchronization between the fetal-derived trophoblast cells and maternal uterine luminal epithelium. Multiple endocrine-driven factors are important for controlling the timely receptivity of the uterus, and this complexity underscores implantation failure as a major cause of recurrent infertility associated with assisted reproductive technologies. One particular cellular structure often hypothesized to promote receptivity is the pinopode or uterodome - a hormonally regulated, large cellular protrusion on the uterine epithelial surface. Recent clinical studies associate pinopodes with favorable fertility outcomes in women, and because they are directly linked to an increase in progesterone levels, the potential utility of these hormone-regulated cell biological structures in predicting or improving implantation in a clinical setting holds promise. In this review, we aim to generate interest in pinopodes from the broader cell biology and endocrinology communities, re-examine methodologies in pinopode research, and identify priorities for future investigation of pinopode structure and function in women's reproductive health.