Enhancing Uterine Receptivity for Embryo Implantation through Controlled Collagenase Intervention
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ABSTRACT: Ineffective endometrial matrix remodeling, a key factor in infertility, impedes embryo implantation in the uterine wall. Our study reveals the cellular and molecular impact of human collagenase-1 administration in mouse uteri, demonstrating enhanced embryo implantation rates. Collagenase-1 promotes remodeling of the endometrial extracellular matrix (ECM), degrading collagen fibers and proteoglycans. This process releases matrix-bound bioactive factors, (e.g. VEGF, decorin), facilitating vascular permeability and angiogenesis. Collagenase-1 elevates embryo implantation regulators, including NK cell infiltration and the key cytokine LIF. Remarkably, uterine tissue maintains structural integrity despite reduced endometrial collagen fiber tension. In-utero collagenase-1 application rescues implantation in the heat stress and embryo transfer models, known for low implantation rates. Importantly, ex-vivo exposure of human uterine tissue to collagenase-1 induces collagen de-tensioning and VEGF release, mirroring remodeling observed in mice. Our research highlights collagenase potential to induce and orchestrate cellular and molecular processes enhancing uterine receptivity for effective embryo implantation. This innovative approach underscores ECM remodeling mechanisms critical for embryo implantation
Project description:Implantation is the attachment of embryo in the endometrium. Failure in implantation is a major cause of early pregnancy loss. During implantation, the temporal uterine lumen closure can help embryo attach to the uterus. In pigs, extending of endometrial folds to form interlocking finger-like projections is a main cause leads to uterine lumen closure during attachment time, but the underlying mechanisms are largely unknown. Our data reveal that pig uterine luminal epithelium (LE) migrate in coordinated groups during extending of endometrial folds. Moreover, the MALDI-TOF MS based N-glycomic characterization of porcine endometrium revealed α2,6-linked sialic acid are highly expressed in pig uterine LE during extending of endometrial folds. To investigated the mechanisms by which α2,6-sialylated proteins in formation of the endometrial folding during implantation in pigs, the α2,6-sialylated proteins in pig uterine LE were characterized by proteomic analysis and those proteins that are involved in cell adhesion, such as E-cadherin, were detected. Finally, our in vivo and in vitro data show that α2,6-sialylation of E-cadherin occurs in accompany with collective epithelial migration. The results provide new insight into the mechanism of pig implantation by identifying that α2,6-sialylation of cell adhesion molecules may participate in formation of extending of endometrial folds through promoting of collective migration of uterine LE.
Project description:Embryo implantation is a complex process which involves biochemical and physiological interactions between an implantation-competent blastocyst and a receptive uterus. However, the exact biochemical changes of uterine fluid, uterus, and plasma during peri-implantation remain unclear. This study aims to characterize the biochemical and metabolic changes that occur during the peri-implantation period of early pregnancy, using mice as an animal model. Gas chromatography-mass spectrometry was used to analyze the metabolite profiles of the uterus, uterine fluid, and maternal plasma at pre-implantation and implantation. The multivariate analyses, ANOVA and Tukey's HSD test, were applied to detect significant changes in metabolites and metabolic pathways. The metabolic networks were reconstructed in silico based on the identified metabolites and KEGG metabolic framework. Between pre-implantation day 1 and day 4, dramatic metabolic changes were observed in the uterine fluid that could be important for blastocyst development and protection against the harsh uterine environment. Palmitoleic acid, fumaric acid, and glutaric acid changed levels at day 4 in the uterus, suggesting that they may be associated with endometrial receptivity. Both the uterus and maternal plasma showed profound changes in cellular metabolism at the early implantation period, including upregulation of branched-chain amino acids and intermediates of one-carbon metabolism, an upregulation of glyoxylate and dicarboxylate metabolism, and downregulation of aerobic respiration; all of which could be involved in the regulation of the maternal-fetal interface, alternative nutrient utilization, and energy preservation for implantation as well as later placentation and fetal development to ensure successful embryo implantation.
Project description:The success of early pregnancy depends largely on the successful implantation of the embryo. Dynamic crosstalk between embryo and mother plays a crucial role in this process, but our understanding is still limited. Here, using the pig as a model, we first comprehensively profile the single-cell transcriptome of early free embryos and corresponding maternal endometrium, identifying embryonic and matched endometrial cells with heterogeneity. We developed a novel tool, ExtraCellTalk, to predict crosstalk between the early embryo and the maternal uterus using uterine luminal proteins as bridges, generating an overall dynamic map of maternal-fetal crosstalk. Through cross-species comparisons, we identified a conserved RBP4/STRA6 pathway in which embryonic-derived RBP4 targets the STRA6 receptor on stromal cells in the endometrium, thereby interacting with endothelial and perivascular cells to regulate their interconversion to promote endometrial remodeling. These maternal-fetal crosstalks and corresponding endometrial changes that we uncovered are essential for subsequent embryo implantation and are the basis for further studies to improve embryo implantation.
Project description:Intrauterine BoTA treatment has a beneficial effect on vascular reconstruction of functional endometrium prior to embryo implantation by increasing endometrial blood flow near the uterine cavity suggesting BoTA treatment as a potential therapeutic strategy for patients who are suffering from repeated implantation failure with the problems with endometrial receptivity.
Project description:Our findings establish a key role for the coregulator, Repressor of Estrogen receptor Activity (REA), in controlling the timing and magnitude of decidualization in human endometrial stromal cells in vitro and in the mouse uterus in vivo, and suggest that REA functions to synchronize uterine differentiation with concurrent embryo development, which is essential for optimal implantation and fertility. The findings highlight that REA physiologically restrains endometrial stromal cell decidualization, controlling the timing and magnitude of decidualization to enable proper synchronization of uterine differentiation with concurrent embryo development that is essential for implantation and optimal fertility.
Project description:The objectives of the present study were to determine whether obesity impacts human decidualization and the endometrial control of trophoblast invasion (both of which are required for embryo implantation) and evaluate the potential involvement of endometrial extracellular vesicles (EVs) in the regulation of these physiological processes. Using primary human cell cultures, we first demonstrated that obesity is associated with significantly lower in vitro decidualization of endometrial stromal cells (ESCs). We then showed that the trophoblastic cell line’s invasive ability was greater in the presence of conditioned media from cultures of ESCs from obese women. Using mass-spectrometry-based quantitative proteomics, we found that EVs isolated from uterine supernatants of biopsies from obese women (vs. nonobese women) presented a molecular signature focused on cell remodeling and angiogenesis. Lastly, the results of functional assays indicated that supplementation of the culture medium with EVs from nonobese women can rescue (at least in part) the defect in in vitro decidualization described in ESCs from obese women. Lastly, the addition of endometrial EVs from obese women (vs. nonobese women) was associated with significantly greater invasive activity by HTR-8/SVneo cells. In conclusion, our results provided new insights into the endometrial EVs’ pivotal role in the poor uterine receptivity observed in obese women.
Project description:Endometrial receptivity plays a vital role in the success of embryo implantation. However, the temporal proteomic profile of porcine endometrium during embryo implantation is still unclear. In this study, the expression of proteins in endometrium on days 9, 10, 11, 12, 13, 14, 15 and 18 of pregnancy (D9, 10, 11, 12, 13, 14, 15 and 18) was profiled via iTRAQ technology. The results showed that 25, 55, 103, 91, 100, 120, 149 proteins were up-regulated, and 24, 70, 169, 159, 164, 161, 198 proteins were down-regulated in porcine endometrium on D10, 11, 12, 13, 14, 15 and 18 compared with that on D9, respectively. Among these differentially expressed (DE) proteins, MQM results indicated that S100A9, S100A12, HRG and IFI6 were differentially expressed in endometrial tissues during embryo implantation period. Bioinformatics analysis showed that the proteins differentially expressed in the 8 comparisons (D10 vs D9, D11 vs D9, D12 vs D9, D13 vs D9, D14 vs D9, D15 vs D9 and D18 vs D9) were involved in important processes and pathways related to immunization, endometrial remodeling, which have a vital effect on embryonic implantation. Our results reveal that RBP4 could regulate the cell proliferation, migration and apoptosis of endometrial epithelial cells and endometrial stromal cells to affect embryo implantation. This research also provides resources for studies of proteins in endometrium during early pregnancy.
Project description:Synchronized cross talk between embryo and endometrium during pre-implantation period is critical for establishment of pregnancy. Extracellular vesicels(EVs) of both embryo and endometrial origin are known to be integral in regulating embryo maternal communication during this time. However, exact molecular signalling pathways or factors that regulate the embryo endometrial communication during pre-conception period remains elusive. Here in this study extracellular vesicles from trophoblast cells were shown to modulate endometrial epithelial cell secretome in favour of embryo implantation and embryo development.
Project description:Inner uterine lining or endometrium is a unique constantly self-renewed adult tissue that is vital for embryo implantation. As the footrace for universal endometrial receptivity markers continues, RNA-seq remains the most powerful tool for transcriptomic marker discovery. In this study, we aimed to elucidate endometrial maturation mechanisms at transcriptomic level and identify novel robust biomarker candidates for endometrial receptivity.