Endometrial stromal cells from women with repeated implantation failure display impaired invasion towards trophoblastic spheroids.

In brief: Implantation failure can occur even after the transfer of good-quality embryos. This study showed that the migration of human endometrial stromal cells towards embryonic trophoblasts is higher in women with live births in the first in vitro fertilization cycle than those with repeated implantation failure, suggesting that the chemotactic response of stroma cells is associated with successful pregnancy. Abstract: The success rate of in vitro fertilization (IVF) remains limited in some women despite transfers of good-quality embryos in repeated attempts. There is no reliable tool for assessing endometrial receptivity. This study aimed to assess the interaction between decidualized human primary endometrial stromal cells (1°-EnSC) and human embryonic stem cell-derived trophoblastic spheroids (BAP-EB) and to compare the invasion ability of decidualized 1°-EnSC towards BAP-EB between women attaining live birth in the first IVF cycle and those with repeated implantation failure (RIF). The invasion of the decidualized human endometrial cell line (T-HESC) and 1°-EnSC towards BAP-EB was studied. Real-time quantitative PCR and immunocytochemistry were employed to determine the expression of decidualization markers at mRNA and protein levels, respectively. Trophoblast-like BAP-EB-96h, instead of early trophectoderm (TE)-like BAP-EB-48h, facilitated the invasion ability of decidualized T-HESC and decidualized 1°-EnSC. Human chorionic gonadotropin at supra-physiological levels promoted the invasiveness of decidualized 1°-EnSC. The extent of BAP-EB-96h-induced invasion was significantly stronger in decidualized 1°-EnSC from women who had a live birth in the first IVF cycle when compared to those with RIF. While no difference was found in the expression of decidualization markers, PRL and IGFBP1 among two groups of women, significantly lower HLA-B was detected in the non-decidualized and decidualized 1°-EnSC from women with RIF. Collectively, the findings suggested that the invasion of decidualized 1°-EnSC towards trophoblast-like BAP-EB-96h was higher in women who had a live birth in the first IVF cycle than those with RIF.

Attachment of a trophoblastic spheroid onto endometrial epithelial cells predicts cumulative live birth in women aged 35 and older.

OBJECTIVE: To evaluate the attachment rate of a human embryonic stem cell-derived trophoblastic spheroid onto endometrial epithelial cells in predicting the cumulative live birth rate of an in vitro fertilization (IVF) cycle. DESIGN: A prospective observational study. SETTING: University hospital and research laboratory. PATIENT(S): A total of 240 infertile women from 2017-2021. INTERVENTION(S): Infertile women with regular cycles attending for IVF were recruited. An endometrial aspirate was collected from a natural cycle 1 month before IVF to determine the BAP-EB attachment rate. MAIN OUTCOME MEASURE(S): Cumulative live birth rates from a stimulated cycle and its derived frozen embryo transfer cycles within 6 months of ovarian stimulation were obtained. RESULT(S): The BAP-EB attachment rate in women who attained a cumulative live birth was similar to that in those who did not. When women were stratified by age into <35 years and ≥35 years, the BAP-EB attachment rate was significantly higher only in women aged ≥35 years having a live birth when compared with those in the same age group without a live birth. Receiver operating characteristic curve analysis of BAP-EB attachment rate in predicting cumulative live birth showed the areas under the curve of 0.559 (95% confidence interval [CI], 0.479-0.639), 0.448 (95% CI, 0.310-0.585), and 0.613 (95% CI, 0.517-0.710) for all ages, an age of <35 years, and an age of ≥35 years, respectively. CONCLUSION(S): The BAP-EB attachment rate offers only a very modest prediction of the cumulative live birth rate in women aged ≥35 years undergoing IVF. CLINICAL TRIAL REGISTRATION NUMBER: NCT02713854 (https://clinicaltrials.gov/ct2/show/NCT02713854; Date of registration, March 21, 2016; date of enrollment of the first subject, August 1, 2017).

Expanded Potential Stem Cells from Human Embryos Have an Open Chromatin Configuration with Enhanced Trophoblast Differentiation Ability.

Human expanded potential stem cells (hEPSC) have been derived from human embryonic stem cells and induced pluripotent stem cells. Here direct derivation of hEPSC from human pre-implantation embryos is reported. Like the reported hEPSC, the embryo-derived hEPSC (hEPSC-em) exhibit a transcriptome similar to morula, comparable differentiation potency, and high genome editing efficiency. Interestingly, the hEPSC-em show a unique H3 lysine-4 trimethylation (H3K4me3) open chromatin conformation; they possess a higher proportion of H3K4me3 bound broad domain (>5 kb) than the reported hEPSC, naive, and primed embryonic stem cells. The open conformation is associated with enhanced trophoblast differentiation potency with increased trophoblast gene expression upon induction of differentiation and success in derivation of trophoblast stem cells with bona fide characteristics. Hippo signaling is specifically enriched in the H3K4me3 broad domains of the hEPSC-. Knockout of the Hippo signaling gene, YAP1 abolishes the ability of the embryo-derived EPSC to form trophoblast stem cells.