Expression of progesterone receptors is significantly impaired in the endometrium of infertile women during the implantation window: a prospective observational study

Hysteroscopic injections of autologous endometrial cells and platelet-rich plasma in patients with thin endometrium: a pilot randomized study

The aim of this study was to evaluate the efficacy of hysteroscopically controlled injections of autologous platelet-rich plasma (PRP) and autologous endometrial cells as a treatment for infertile women with thin endometrium. The study enrolled 115 patients with thin endometrium (< 7 mm at implantation window) and infertility, who were divided into groups: Group 1 (the control) underwent conservative therapy; Group 2 received intraendometrial PRP injections instead of the conservative therapy; Group 3 received identical injections after conservative therapy; Group 4 received injections of the autologous endometrial cells suspended in PRP. A single injection dose of PRP contained 0.6-0.7 × 10¹¹ of platelets. The levels of PDGF-BB and VEGF in PRP were increased compared with ordinary plasma. The autologous endometrial cells, obtained from pipelle biopsies, constituted heterogeneous cell populations containing stromal and epithelial cells. Intraendometrial PRP injections had significant impact on endometrial thickness and local microcirculation in Group 2 and Group 3. In Group 4, injections of PRP reinforced with endometrial cells also facilitated a significant increase in endometrial thickness. This work describes a novel approach for infertility treatment in patients with refractory thin endometrium. PRP injections and injections of the endometrial cells suspended in PRP into endometrium enhanced cell proliferation and angiogenesis.

Current Knowledge on Endometriosis Etiology: A Systematic Review of Literature

Objective

To review the mechanisms of endometriosis development, including those related to epigenetic mutations, cellular dysregulation, inflammatory processes, and oxidative stress.

Methods

A systematic literature review regarding current aspects of endometriosis etiology, genesis and development was performed using the PubMed, Google Scholar, and eLibrary databases. Keywords included endometriosis, etiology, development, genesis, associations and mechanisms. A multilingual search was performed.

Results

Several mechanisms underline the pathophysiological pathways for endometriosis development. Epigenetic mutations, external and internal influences, and chronic conditions have a significant impact on endometriosis development, survival and regulation. Several historically valid theories on endometriosis development were discussed, as well as updated findings.

Conclusion

Despite recent advances, fundamental problems in understanding endometriosis remain unresolved. The identification of unknown circulating epithelial progenitors or stem cells that are responsible for epithelial growth in both the endometrium and endometriotic foci seems to be the next step in solving these questions.

Evaluation of Expression and Phosphorylation of Progesterone Receptor in Endometrial Stromal Cells of Patients with Recurrent Implantation Failure Compared to Healthy Fertile Women

Recurrent implantation failure (RIF) is the repeated failure of good-quality embryos in implantation process following several assisted reproduction cycles. Disruption of the endometrial receptivity is one of the main causes of RIF. Progesterone plays a pivotal role in the endometrial receptivity through the regulation of gene expression pattern by binding to its receptors in the endometrial cells. The aim of this study was to evaluate the expression level of progesterone receptor (PR) and its phosphorylated form in the endometrial stromal cells (eSC) of RIF patients and compare it to the eSC of healthy fertile women as control group. After isolation of the eSC from biopsy samples of RIF patients and healthy fertile women and their characterization, expression levels of PR mRNA, PR protein, and phospho-Ser294 PR protein were evaluated by quantitative real-time PCR and immunofluorescence staining, respectively. The results demonstrated a significant reduction in PR mRNA expression (P < 0.01.) and phospho-Ser294 PR protein (P < 0.05) level in RIF patients compared to the control group. These data for the first time suggest that the expression of PR and its phosphorylated form are impaired in RIF patients. Therefore, designing therapeutic methods for improving PR expression status and its regulation in the endometrium of RIF patients may help in improving the final reproductive outcomes of these cases.

Overexpression of estrogen and progesterone receptors as indicator of endometrial receptivity disorder in women with early miscarriage

Background ― The endometrial factor is important in miscarriage (MC) pathogenesis. Objective. To perform a morphofunctional evaluation of endometrium in the patients with uncertain MC cause in anamnesis. Material and methods ― We examined 48 women 23-40 yo [30 (27, 35)]: the main group consisted of 33 patients with early MC in their medical history, while the control group included 15 healthy fertile women. All women had an ovulatory menstrual cycle, normal levels of gonadotropic and thyroid hormones, prolactin, and androgens. Ultrasound and hormonal examinations, along with morphological investigation of endometrial biopsies were performed. Data presented as median with lower and upper quartiles – Me (LQ, UQ). Results ― In 64% (n=21) of women in the main group, we detected inferior secretory phase of their endometrial cycle, focal fibrosis of endometrial stroma; synchronous overexpression of estrogen (ER) and progesterone (PR) receptors in endometrial glands and stroma. ER in the glands was 240 (160, 280) vs. 130 (80, 210) in the stroma, while PR values were 270 (210, 290) in the glands vs. 270 (240, 280) in the stroma: differences from the control group were significant (p<0.01). Remaining women in the main group (36%, n=12) and all women in the control group had full secretory transformation of the endometrium and normal expression of ER and PR. The levels of estradiol and PR in the blood of women with early MC in anamnesis, with different variants of ER and PR expression in the endometrium, did not differ significantly from the control group and corresponded to the reference values. Conclusion ― Nearly two-thirds of women with early miscarriage in anamnesis exhibited overexpression of ER and PR in the endometrium, which may be one of the indicators of its decreased receptivity status.

Large, Non-Cavity Distorting Intramural Leiomyomas Decrease Leukemia Inhibitory Factor in the Secretory Phase Endometrium

Despite mounting evidence that large intramural leiomyomas decrease fecundity during in vitro fertilization cycles, few studies have demonstrated a mechanism for this impact. We hypothesize that large intramural leiomyomas (IM) decrease the expression of endometrial implantation factors during the window of implantation. We prospectively recruited sub-fertile patients with IM 3 cm or greater in size planning myomectomy and performed endometrial biopsies the day of planned myomectomy (n = 9). Preoperative screening demonstrated no intercavitary lesions. Control endometrial samples were obtained from young, normally menstruating women free of uterine leiomyomas (n = 8). Endometrial samples were obtained in the mid-secretory phase (average cycle day for control patients and intramural leiomyoma patients were 24.5 and 21.3, respectively). Expression of implantation markers HOXA10, leukemia inhibitory factor (LIF), ER-α, and PR was compared using quantitative immunohistochemistry. Standard descriptive statistics were used to compare H-scores between the cohorts. Patients with intramural leiomyomas were found to have decreased LIF compared to controls (p value < 0.001). Expressions of HOXA10 and PR were no different between cohorts; however, ER-α showed a trend toward increased expression in the fibroid cohort (p value 0.07). LIF is downregulated in the endometrium of patients with large IM. This study is among the first to show decreased LIF expression in patients with uterine leiomyomas. We hypothesize that this difference from previously published work is due to sampling the endometrium at the height of LIF expression. Further work is needed to show if LIF downregulation is corrected with leiomyoma resection.

Clues to Non-Invasive Implantation Window Monitoring: Isolation and Characterisation of Endometrial Exosomes

Despite the significant advances in the last decades, low implantation rate per transferred embryo still remains a major concern in assisted reproductive techniques, highlighting a need to better characterize endometrial receptivity also by mean of specific biomarkers. Based on physiology and on the intimate contact with endometrium as the tissue of interest, in this study we developed and validated an optimized protocol that uses extracellular vesicles (EVs) recovered from uterine flushings and from a cervical brush, the latter never used until now as an EVs source, as surrogates for endometrial biopsies. This method combines the safety of sampling with the ability to study the expression profile across the uterine cycle. We have compared the yield and composition of EVs recovered from different biofluids samples and fractions thereof, opting for chemical precipitation as the EV isolation procedure, assuring the highest yield without introducing any bias in specific EV recovery. Moreover, collected EVs, in particular exosome-like vesicles, express putative endometrial markers, such as glycodelin A and receptors for estrogen and progesterone, thus confirming their endometrial origin. We also identified uterine flushing EVs, in particular those recovered from its mucous fraction, as the richest source of endometrial transcripts, likely correlated to cellular (epithelial) origin of these vesicles. Finally, our pilot quantitative assessment of three endometrial gene profiles, in samples collected at different time points along the luteal phase, revealed the fluctuations apparently recapitulating gene expression variability prior reported during the menstrual cycle. Unlike tissue biopsy that is subjected to inter- and intra-sample differences, our data suggest that EVs from liquid biopsies (from uterine flushings and a cervical brush) obtained through less-invasive procedures, can be substrate to detect and track the tissue representative expression profiles, better depicting the total endometrium complexity.

Unexplained infertility patients present the mostly impaired levels of progesterone receptors: Prospective observational study

PROBLEM

Τo assess the endometrial expression of progesterone receptors in various subgroups of infertile women during implantation window. ΜETHODS: A prospective observational study was performed during March 2013-February 2017. Infertile women were categorized to those with tubal factor, ovarian failure, endometriosis or unexplained infertility. Endometrial biopsy was obtained on 7th-8th postovulatory day. Total progesterone receptors' PR(A + B) and type-B receptors' (PR-B) expression were compared between all categories of infertile and fruitful controls.

RESULTS

There were overall 30 patients with tubal factor infertility (group 1), 30 with ovarian failure (group 2), 20 with endometriosis (group 3) and 20 with unexplained infertility (group 4). The control group consisted of 30 fertile patients. Patients with unexplained infertility presented the lowest levels of epithelial endometrial expression both regarding PR(A + B) and PR-B receptors. PgR(A + B) h-score in luminal epithelial cells was 106.4 ± 14.7 for cases with unexplained infertility vs 219.7 ± 15.8 for controls (P < .001). Similarly, PgR(A + B) h-score in glandular epithelial cells was 109.7 ± 13.9 vs 220.1 ± 17.2 (P < .001). Relative remarks were made for type-B progesterone receptors.

CONCLUSION

Εndometrial expression of progesterone receptors is impaired in women with unexplained infertility. Therapeutic strategies targeting on improving progesterone receptors' expression may significantly affect final reproductive outcome.