Deciphering mouse uterine receptivity for embryo implantation at single‐cell resolution

As a crucial step for human reproduction, embryo implantation is a low-efficiency process. Despite rapid advances in recent years, the molecular mechanism underlying embryo implantation remains poorly understood. Here, we used the mouse as an animal model and generated a single-cell transcriptomic atlas of embryo implantation sites. By analyzing inter-implantation sites of the uterus as control, we were able to identify global gene expression changes associated with embryo implantation in each cell type. Additionally, we predicted signaling interactions between uterine luminal epithelial cells and mural trophectoderm of blastocysts, which represent the key mechanism of embryo implantation. We also predicted signaling interactions between uterine epithelial-stromal crosstalk at implantation sites, which are crucial for post-implantation development. Our data provide a valuable resource for deciphering the molecular mechanism underlying embryo implantation.

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Heparan Sulfate Proteoglycan Sulfation Regulates Uterine Differentiation and Signaling During Embryo Implantation

Endocrinology ◽

10.1210/en.2018-00105 ◽

2018 ◽

Vol 159 (6) ◽

pp. 2459-2472 ◽

Cited By ~ 2

Author(s):

Yan Yin ◽

Adam Wang ◽

Li Feng ◽

Yu Wang ◽

Hong Zhang ◽

...

Keyword(s):

Signal Transduction ◽

Heparan Sulfate ◽

Signaling Pathways ◽

Reproductive Tract ◽

Ovarian Function ◽

Embryo Implantation ◽

Uterine Epithelium ◽

Female Reproductive Tract ◽

Uterine Receptivity ◽

Mouse Uterus

Abstract To prepare for embryo implantation, the uterus must undergo a series of reciprocal interactions between the uterine epithelium and the underlying stroma, which are orchestrated by ovarian hormones. During this process, multiple signaling pathways are activated to direct cell proliferation and differentiation, which render the uterus receptive to the implanting blastocysts. One important modulator of these signaling pathways is the cell surface and extracellular matrix macromolecules, heparan sulfate proteoglycans (HSPGs). HSPGs play crucial roles in signal transduction by regulating morphogen transport and ligand binding. In this study, we examine the role of HSPG sulfation in regulating uterine receptivity by conditionally deleting the N-deacetylase/N-sulfotransferase (NDST) 1 gene (Ndst1) in the mouse uterus using the Pgr-Cre driver, on an Ndst2- and Ndst3-null genetic background. Although development of the female reproductive tract and subsequent ovarian function appear normal in Ndst triple-knockout females, they are infertile due to implantation defects. Embryo attachment appears to occur but the uterine epithelium at the site of implantation persists rather than disintegrates in the mutant. Uterine epithelial cells continued to proliferate past day 4 of pregnancy, accompanied by elevated Fgf2 and Fgf9 expression, whereas uterine stroma failed to undergo decidualization, as evidenced by lack of Bmp2 induction. Despite normal Indian hedgehog expression, transcripts of Ptch1 and Gli1, both components as well as targets of the hedgehog (Hh) pathway, were detected only in the subepithelial stroma, indicating altered Hh signaling in the mutant uterus. Taken together, these data implicate an essential role for HSPGs in modulating signal transduction during mouse implantation.

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Uterine Insulin Sensitivity Defects Induced Embryo Implantation Loss Associated with Mitochondrial Dysfunction-Triggered Oxidative Stress

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/6655685 ◽

2021 ◽

Vol 2021 ◽

pp. 1-18

Author(s):

Meixia Chen ◽

Jie Li ◽

Bo Zhang ◽

Xiangfang Zeng ◽

Xiangzhou Zeng ◽

...

Keyword(s):

Oxidative Stress ◽

Insulin Sensitivity ◽

Mitochondrial Dysfunction ◽

Insulin Signaling ◽

Embryo Implantation ◽

Fetal Loss ◽

Enrichment Analysis ◽

Uterine Receptivity ◽

Resistant Mouse

Scope. Implantation loss is a considerable cause of early pregnancy loss in humans and mammalian animals. It is not addressed how proliferative uterine defects implicate in implantation loss. Methods and Results. Herein, a comprehensive proteomic analysis was conducted on proliferative endometria from sows with low and normal reproductive performance (LRP and NRP, respectively). Enrichment analysis of differentially expressed proteins revealed alterations in endometrial remodeling, substance metabolism (mainly lipid, nitrogen, and retinol metabolism), immunological modulation, and insulin signaling in LRP sows. Importantly, aberrant lipid metabolite accumulation and dysregulation of insulin signaling were coincidently confirmed in endometria of LPR sows, proving an impaired insulin sensitivity. Furthermore, established high-fat diet- (HFD-) induced insulin-resistant mouse models revealed that uterine insulin resistance beginning before pregnancy deteriorated uterine receptivity and decreased implantation sites and fetal numbers. Mitochondrial biogenesis and fusion were decreased, and reactive oxygen species was overproduced in uteri from the HFD group during the implantation period. Ishikawa and JAR cells directly demonstrated that oxidative stress compromised implantation in vitro. Conclusions. This study demonstrated that uterine insulin sensitivity impairment beginning before pregnancy resulted in implantation and fetal loss associated with oxidative stress induced by mitochondrial dysfunction.

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Single-cell RNA Expression of SARS-CoV-2 Cell Entry Factors in Human Endometrium during Preconception

10.1101/2020.09.14.296806 ◽

2020 ◽

Author(s):

Felipe Vilella ◽

Wanxin Wang ◽

Inmaculada Moreno ◽

Stephen R. Quake ◽

Carlos Simon

Keyword(s):

Single Cell ◽

Rna Sequencing ◽

Viral Entry ◽

Embryo Implantation ◽

Human Endometrium ◽

Cell Entry ◽

Rna Expression ◽

Endometrial Cells ◽

Single Cell Rna Sequencing ◽

Low Efficiency

AbstractWe investigated potential SARS-CoV-2 tropism in human endometrium by single-cell RNA-sequencing of viral entry-associated genes in healthy women. Percentages of endometrial cells expressing ACE2, TMPRSS2, CTSB, or CTSL were <2%, 12%, 80%, and 80%, respectively, with 0.7% of cells expressing all four genes. Our findings imply low efficiency of SARS-CoV-2 infection in the endometrium before embryo implantation, providing information to assess preconception risk in asymptomatic carriers.

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Uterine aquaporin expression is dynamically regulated by estradiol and progesterone and ovarian stimulation disrupts embryo implantation without affecting luminal closure

MHR Basic science of reproductive medicine ◽

10.1093/molehr/gaaa007 ◽

2020 ◽

Vol 26 (3) ◽

pp. 154-166 ◽

Cited By ~ 2

Author(s):

Vanessa de Oliveira ◽

Jennifer Schaefer ◽

Basim Abu-Rafea ◽

George A Vilos ◽

Angelos G Vilos ◽

...

Keyword(s):

Embryo Development ◽

Ovarian Stimulation ◽

Embryo Implantation ◽

Pathological State ◽

Implantation Failure ◽

Uterine Receptivity ◽

Spatial Expression ◽

Aqp4 Expression ◽

Abnormal Expression ◽

Aquaporin Gene

Abstract The study investigated the effect of normal and supraphysiological (resulting from gonadotropin-dependent ovarian stimulation) levels of estradiol (E2) and progesterone (P4) on mouse uterine aquaporin gene/protein (Aqp/AQP) expression on Day 1 (D1) and D4 of pregnancy. The study also examined the effect of ovarian stimulation on uterine luminal closure and uterine receptivity on D4 of pregnancy and embryo implantation on D5 and D7 of pregnancy. These analyses revealed that the expression of Aqp3, Aqp4, Aqp5 and Aqp8 is induced by E2 while the expression of Aqp1 and Aqp11 is induced by P4. Additionally, P4 inhibits E2 induction of Aqp3 and Aqp4 expression while E2 inhibits Aqp1 and Aqp11 expression. Aqp9, however, is constitutively expressed. Ovarian stimulation disrupts Aqp3, Aqp5 and Aqp8 expression on D4 and AQP1, AQP3 and AQP5 spatial expression on both D1 and D4, strikingly so in the myometrium. Interestingly, while ovarian stimulation has no overt effect on luminal closure and uterine receptivity, it reduces implantation events, likely through a disruption in myometrial activity and embryo development. The wider implication of this study is that ovarian stimulation, which results in supraphysiological levels of E2 and P4 and changes (depending on the degree of stimulation) in the E2:P4 ratio, triggers abnormal expression of uterine AQP during pregnancy, and this is associated with implantation failure. These findings lead us to recognize that abnormal expression would also occur under any pathological state (such as endometriosis) that is associated with changes in the normal E2:P4 ratio. Thus, infertility among these patients might in part be linked to abnormal uterine AQP expression.

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MicroRNAs in Small Extracellular Vesicles Indicate Successful Embryo Implantation during Early Pregnancy

Cells ◽

10.3390/cells9030645 ◽

2020 ◽

Vol 9 (3) ◽

pp. 645 ◽

Cited By ~ 4

Author(s):

Qiang Tan ◽

Shuang Shi ◽

Jingjie Liang ◽

Xiaowei Zhang ◽

Dingren Cao ◽

...

Keyword(s):

Expression Profiles ◽

Embryo Implantation ◽

Extracellular Vesicle ◽

Synchronous Communication ◽

Normal Embryo ◽

Multivesicular Bodies ◽

Uterine Receptivity ◽

Database Analysis ◽

Mirna Expression Profiles ◽

Future Practice

Synchronous communication between the developing embryo and the receptive endometrium is crucial for embryo implantation. Thus, uterine receptivity evaluation is vital in managing recurrent implantation failure (RIF). The potential roles of small extracellular vesicle (sEV) miRNAs in pregnancy have been widely studied. However, the systematic study of sEVs derived from endometrium and its cargos during the implantation stage have not yet been reported. In this study, we isolated endometrium-derived sEVs from the mouse endometrium on D2 (pre-receptive phase), D4 (receptive phase), and D5 (implantation) of pregnancy. Herein, we reveal that multivesicular bodies (MVBs) in the endometrium increase in number during the window of implantation (WOI). Moreover, our findings indicate that CD63, a well-known sEV marker, is expressed in the luminal and glandular epithelium of mouse endometrium. The sEV miRNA expression profiles indicated that miR-34c-5p, miR-210, miR-369-5p, miR-30b, and miR-582-5p are enriched during WOI. Further, we integrated the RIF’s database analysis results and found out that miR-34c-5p regulates growth arrest specific 1 (GAS1) for normal embryo implantation. Notably, miR-34c-5p is downregulated during implantation but upregulated in sEVs. An implication of this is the possibility that sEVs miR-34c-5p could be used to evaluate uterine states. In conclusion, these findings suggest that the endometrium derived-sEV miRNAs are potential biomarkers in determining the appropriate period for embryo implantation. This study also has several important implications for future practice, including therapy of infertility.

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Uterine Receptivity

Reproduction Fertility and Development ◽

10.1071/rd9920645 ◽

1992 ◽

Vol 4 (6) ◽

pp. 645 ◽

Cited By ~ 3

Author(s):

PAW Rogers

Keyword(s):

Ovulation Induction ◽

Embryo Implantation ◽

Morphological Markers ◽

Human Uterus ◽

Uterine Receptivity ◽

Morphometric Measurement ◽

New Techniques ◽

Cellular Processes ◽

Functional Capabilities ◽

Human Implantation

Reduced uterine receptivity can play a major role in human infertility, particularly following ovarian stimulation as occurs during ovulation induction and IVF. Many of the conventional histological and morphological markers used to identify normal progestational changes in the human uterus are inadequate as markers of uterine receptivity for implantation, and new techniques including ultrasound and morphometric measurement will be required. At the same time, a'better understanding of the cellular processes involved in human implantation is required if we are to identify markers of uterine receptivity. Recent observations suggest that the uterus is normally a barrier to embryo implantation and that uterine receptivity is in fact the loss of this barrier function, rather than the acquisition of new structural or functional capabilities.

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Follistatin is critical for mouse uterine receptivity and decidualization

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1620903114 ◽

2017 ◽

Vol 114 (24) ◽

pp. E4772-E4781 ◽

Cited By ~ 7

Author(s):

Paul T. Fullerton ◽

Diana Monsivais ◽

Ramakrishna Kommagani ◽

Martin M. Matzuk

Keyword(s):

Molecular Mechanisms ◽

Recurrent Miscarriage ◽

Embryo Implantation ◽

Bmp Signaling ◽

Conditional Knockout ◽

Uterine Receptivity ◽

Vitro Fertilization ◽

Morphogenetic Protein ◽

Proliferation And Differentiation

Embryo implantation remains a significant challenge for assisted reproductive technology, with implantation failure occurring in ∼50% of in vitro fertilization attempts. Understanding the molecular mechanisms underlying uterine receptivity will enable the development of new interventions and biomarkers. TGFβ family signaling in the uterus is critical for establishing and maintaining pregnancy. Follistatin (FST) regulates TGFβ family signaling by selectively binding TGFβ family ligands and sequestering them. In humans, FST is up-regulated in the decidua during early pregnancy, and women with recurrent miscarriage have lower endometrial expression of FST during the luteal phase. Because global knockout of Fst is perinatal lethal in mice, we generated a conditional knockout (cKO) of Fst in the uterus using progesterone receptor-cre to study the roles of uterine Fst during pregnancy. Uterine Fst-cKO mice demonstrate severe fertility defects and deliver only 2% of the number of pups delivered by control females. In Fst-cKO mice, the uterine luminal epithelium does not respond properly to estrogen and progesterone signals and remains unreceptive to embryo attachment by continuing to proliferate and failing to differentiate. The uterine stroma of Fst-cKO mice also responds poorly to artificial decidualization, with lower levels of proliferation and differentiation. In the absence of uterine FST, activin B expression and signaling are up-regulated, and bone morphogenetic protein (BMP) signals are impaired. Our findings support a model in which repression of activin signaling by FST enables uterine receptivity by preserving critical BMP signaling.

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Gram-Negative Bacterial LPS Induced Poor Uterine Receptivity and Implantation Failure in Mouse: Alterations in IL-1β Expression in the Preimplantation Embryo and Uterine Horns

Infectious Diseases in Obstetrics and Gynecology ◽

10.1080/10647440500147885 ◽

2005 ◽

Vol 13 (3) ◽

pp. 125-133 ◽

Cited By ~ 18

Author(s):

Kaushik Deb ◽

Madan Mohan Chaturvedi ◽

Yogesh Kumar Jaiswal

Keyword(s):

Cross Sections ◽

Pregnancy Loss ◽

Embryo Implantation ◽

Preimplantation Embryos ◽

Soluble Form ◽

Implantation Failure ◽

Perinatal Complications ◽

Uterine Receptivity ◽

Gram Negative ◽

Blastocyst Implantation

Genito-urinary tract or systemic infections of the gram-negative bacteria in pregnant women, causes abortions, preterm labor, and several other perinatal complications. LPS is the most potent antigenic component of the gram-negative bacterial cell wall and is known to modulate the expression of various proinflammatory cytokines. Here we investigate the role of the soluble form of IL-1 i.e., IL-1β in the ‘minimum dose’ of LPS induced pregnancy loss in mice. Uterine cross-sections on each day of the preimplantation period of pregnancy were examined histopathologically for finding out LPS induced changes in the uterine preparation for embryo implantation. The expression of IL-1β in the various stages of the preimplantation period of pregnancy was studied by RT-PCR in the embryos and the uterine horns of the LPS treated and normal pregnant mice. We found that LPS significantly alters the proliferation of the glandular epithelium, luminal epithelium and stroma during the preimplantation period. We also found large infiltration of macrophages into the uterine horns of the LPS treated animals. The level and pattern of IL-1β expression in the preimplantation embryos and uterine horns were also altered in LPS treated animals. These observations indicate that LPS can alter the uterine preparation for blastocyst implantation, which could be due to the change in the IL-1β expression in the uterine horns. However, a change in the expression pattern of IL-1β in the preimplantation embryos underlines the significance of this molecule in LPS induced pregnancy loss or implantation failure in mouse.

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Maternal Hoxa10 is required for pinopod formation in the development of mouse uterine receptivity to embryo implantation

Developmental Dynamics ◽

10.1002/dvdy.1209 ◽

2001 ◽

Vol 222 (3) ◽

pp. 538-544 ◽

Cited By ~ 71

Author(s):

Catherine N. Bagot ◽

Harvey J. Kliman ◽

Hugh S. Taylor

Keyword(s):

Embryo Implantation ◽

Uterine Receptivity

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