Transcriptome analysis of endometrial tissues following GnRH agonist treatment in a mouse adenomyosis model

[Adenomyosis pathophysiology: An unresolved enigma]

Adenomyosis is a chronic benign uterine disease characterized by the presence of endometrial glands and stroma within the myometrium. It is a heterogeneous disease, presenting various clinical forms, depending on the location of the ectopic lesions within the myometrium. Adenomyosis can be responsible for several symptoms such as dysmenorrhea, abnormal uterine bleeding and/or infertility. Its pathophysiology is a real conundrum and several theories have been proposed: development of adenomyosis lesion could initiate de novo from Mullerian rests or from stem cells. Moreover, multiple factors could be involved in initiating lesions, including specific hormonal, immune and/or genetic changes. The objective of this review is to provide an update on adenomyosis pathophysiology, in particular on the various theories proposed concerning the invasion of the myometrium by endometrial cells and the inducing mechanisms, and to study the link between the physiopathology, the symptoms and the medical treatments.

Hypoxia and its possible relationship with endometrial receptivity in adenomyosis: a preliminary study

BACKGROUND

Adenomyosis (AM) is an important cause of female infertility. However, the underlying mechanism remains unclear. This report describes a preliminary study of hypoxia and its possible association with endometrial receptivity in AM.

METHODS

The study was divided into in vitro and in vivo experiments. In vitro, expression levels of the endometrial receptivity markers HOXA10 and HOXA11 in the implantation period were examined using real-time PCR and western blotting. Endometrial expression of hypoxia-inducible factor (HIF)-1α, HIF-2α, and HIF-3α was determined using immunohistochemistry. In vivo, using an AM mouse model established by oral administration of tamoxifen, we inhibited expression of HIF-2α using an HIF-2α antagonist (PT2399; 30 mg/kg body weight, twice daily by oral gavage for 2 days) and then examined expression levels of Hoxa10 and Hoxa11 using real-time PCR and western blotting.

RESULTS

Endometrial mRNA and protein expression levels of HOXA10 and HOXA11 were significantly lower in patients with AM than in control patients. Expression of HIF-2α was significantly higher in the AM group than in the control group, whereas that of HIF-1α and HIF-3α was equivalent in both groups. In vivo analysis showed that administration of the HIF-2α antagonist resulted in increased expression of Hoxa10 and Hoxa11 at both the mRNA and protein levels in AM model mice.

CONCLUSIONS

HIF-2α overexpression may be one reason for decreased endometrial receptivity in AM. The current findings provide insight into HIF-2α-mediated AM-related infertility and suggest that PT2399 has potential as a treatment for AM.

TRIAL REGISTRATION

This trial was retrospectively registered.

The freeze-all strategy after IVF: which indications?

The freeze-all strategy is gaining popularity worldwide as an alternative to the conventional fresh embryo transfer. It consists of cryopreservation of the entire embryo cohort and the embryo transfer in a subsequent cycle that takes place separately from ovarian stimulation. The freeze-all strategy was initially a 'rescue' strategy for women at high risk of ovarian hyperstimulation syndrome; however, this approach has been extended to other indications as a scheduled strategy to improve implantation rates. This assumes that ovarian stimulation can alter endometrial receptivity in fresh cycles owing to the effect of supraphysiological levels of steroids on endometrial maturation. The procedure, however, has not been associated with increased live birth rates in all infertile couples, and concerns have been raised about the occurrence of several adverse perinatal outcomes. It is, therefore, crucial to identify in which subgroups of patients a freeze-all strategy could be beneficial. The aim of this review is to summarize current scientific research in this field to highlight potential indications for this strategy and to guide clinicians in their daily practice.

Animal Models of Adenomyosis

Adenomyosis is a nonmalignant uterine disorder in which endometrial tissue exists within and grows into the myometrium. Animal models have generated limited insight into the still-unclear pathogenesis of adenomyosis, provided a platform for preclinical screening of many drugs and compounds with potential as therapeutics, and elucidated mechanisms underlying the pain and fertility issues that occur in many women with the disease. Spontaneous adenomyosis has been studied in nonhuman primates, primarily in the form of case reports. Adenomyosis is routinely experimentally induced in mice through methods such as neonatal tamoxifen exposure, pituitary engraftment, and human tissue xenotransplantation. Several studies have also reported hormonal or environmental toxicant exposures that give rise to murine adenomyosis, and genetically engineered models have been created that recapitulate the human-like condition, most notably involving alteration of β-catenin expression. This review describes the animal models for adenomyosis and their contributions to our understanding of the factors underpinning the development of symptoms. Animal models represent a unique opportunity for understanding the molecular basis of adenomyosis and developing efficacious treatment options for affected women. Herein, we assess their different potentials and limitations with regard to identification of new therapeutic interventions and reflect on future directions for research and drug validation.

Window of Implantation is Significantly Displaced in Patients with Adenomyosis with Previous Implantation Failure as Determined by Endometrial Receptivity Assay

Background:

Adenomyosis is associated with implantation failure and poor reproductive performance in IVF/ICSI cycles.

Aims:

To compare if window of implantation (WOI) is displaced in patients having adenomyosis compared to controls using endometrial receptivity array (ERA) test.

Settings and Design:

Retrospective Case control study. 374 patients with previous one or more IVF failures who underwent ERA test between 2013-2016 at our centre were enrolled. Patients were divided into two groups; Group A-36 patients with adenomyosis (study group) and Group B- 338 patients without adenomyosis (controls).

Statistical Analysis:

Normality assumptions for continuous variables were tested using Kolmogorov Smirnov test. Mean values of two groups were compared using Student's t-independent test. Frequency data by categories were compared using Chi-square/Fisher's exact test. Risk ratio and 95% confidence limits were calculated. P < 0.05 was considered for statistical significance.

Results:

WOI was displaced (Non Receptive ERA) significantly in adenomyosis 47.2% (17/36) compared to controls 21.6% (73/338) (P < 0.001, CI-8.7%-42.5%) making risk ratio of displaced WOI in adenomyosis versus controls to be 2:1. The incidence of RIF was 66.6% in adenomyosis compared to 34.9% in controls (P < 0.001, CI- 15.5%-47.9%). Pregnancy rate after personalized embryo transfer in adenomyosis group was 62.5%, signifying displaced WOI as a cause of implantation failure in adenomyosis patients with previous implantation failure.

Conclusions:

Our study suggests it is prudent to evaluate Endometrial receptivity before embryo transfer in patients with adenomyosis to avoid wastage of good embryos.