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Ruane PT, Garner T, Parsons L, Babbington PA, Wangsaputra I, Kimber SJ, Stevens A, Westwood M, Brison DR, Aplin JD. Trophectoderm differentiation to invasive syncytiotrophoblast is promoted by endometrial epithelial cells during human embryo implantation. Hum Reprod 2022; 37:777-792. [PMID: 35079788 PMCID: PMC9398450 DOI: 10.1093/humrep/deac008] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 11/24/2021] [Indexed: 01/12/2023] Open
Abstract
STUDY QUESTION How does the human embryo breach the endometrial epithelium at implantation? SUMMARY ANSWER Embryo attachment to the endometrial epithelium promotes the formation of multinuclear syncytiotrophoblast from trophectoderm, which goes on to breach the epithelial layer. WHAT IS KNOWN ALREADY A significant proportion of natural conceptions and assisted reproduction treatments fail due to unsuccessful implantation. The trophectoderm lineage of the embryo attaches to the endometrial epithelium before breaching this barrier to implant into the endometrium. Trophectoderm-derived syncytiotrophoblast has been observed in recent in vitro cultures of peri-implantation embryos, and historical histology has shown invasive syncytiotrophoblast in embryos that have invaded beyond the epithelium, but the cell type mediating invasion of the epithelial layer at implantation is unknown. STUDY DESIGN, SIZE, DURATION Fresh and frozen human blastocyst-stage embryos (n = 46) or human trophoblast stem cell (TSC) spheroids were co-cultured with confluent monolayers of the Ishikawa endometrial epithelial cell line to model the epithelial phase of implantation in vitro. Systems biology approaches with published transcriptomic datasets were used to model the epithelial phase of implantation in silico. PARTICIPANTS/MATERIALS, SETTING, METHODS Human embryos surplus to treatment requirements were consented for research. Day 6 blastocysts were co-cultured with Ishikawa cell layers until Day 8, and human TSC spheroids modelling blastocyst trophectoderm were co-cultured with Ishikawa cell layers for 48 h. Embryo and TSC morphology was assessed by immunofluorescence microscopy, and TSC differentiation by real-time quantitative PCR (RT-qPCR) and ELISA. Single-cell human blastocyst transcriptomes, and bulk transcriptomes of TSC and primary human endometrial epithelium were used to model the trophectoderm-epithelium interaction in silico. Hypernetworks, pathway analysis, random forest machine learning and RNA velocity were employed to identify gene networks associated with implantation. MAIN RESULTS AND THE ROLE OF CHANCE The majority of embryos co-cultured with Ishikawa cell layers from Day 6 to 8 breached the epithelial layer (37/46), and syncytiotrophoblast was seen in all of these. Syncytiotrophoblast was observed at the embryo-epithelium interface before breaching, and syncytiotrophoblast mediated all pioneering breaching events observed (7/7 events). Multiple independent syncytiotrophoblast regions were seen in 26/46 embryos, suggesting derivation from different regions of trophectoderm. Human TSC spheroids co-cultured with Ishikawa layers also exhibited syncytiotrophoblast formation upon invasion into the epithelium. RT-qPCR comparison of TSC spheroids in isolated culture and co-culture demonstrated epithelium-induced upregulation of syncytiotrophoblast genes CGB (P = 0.03) and SDC1 (P = 0.008), and ELISA revealed the induction of hCGβ secretion (P = 0.03). Secretory-phase primary endometrial epithelium surface transcriptomes were used to identify trophectoderm surface binding partners to model the embryo-epithelium interface. Hypernetwork analysis established a group of 25 epithelium-interacting trophectoderm genes that were highly connected to the rest of the trophectoderm transcriptome, and epithelium-coupled gene networks in cells of the polar region of the trophectoderm exhibited greater connectivity (P < 0.001) and more organized connections (P < 0.0001) than those in the mural region. Pathway analysis revealed a striking similarity with syncytiotrophoblast differentiation, as 4/6 most highly activated pathways upon TSC-syncytiotrophoblast differentiation (false discovery rate (FDR < 0.026)) were represented in the most enriched pathways of epithelium-coupled gene networks in both polar and mural trophectoderm (FDR < 0.001). Random forest machine learning also showed that 80% of the endometrial epithelium-interacting trophectoderm genes identified in the hypernetwork could be quantified as classifiers of TSC-syncytiotrophoblast differentiation. This multi-model approach suggests that invasive syncytiotrophoblast formation from both polar and mural trophectoderm is promoted by attachment to the endometrial epithelium to enable embryonic invasion. LARGE SCALE DATA No omics datasets were generated in this study, and those used from previously published studies are cited. LIMITATIONS, REASONS FOR CAUTION In vitro and in silico models may not recapitulate the dynamic embryo-endometrial interactions that occur in vivo. The influence of other cellular compartments in the endometrium, including decidual stromal cells and leukocytes, was not represented in these models. WIDER IMPLICATIONS OF THE FINDINGS Understanding the mechanism of human embryo breaching of the epithelium and the gene networks involved is crucial to improve implantation success rates after assisted reproduction. Moreover, early trophoblast lineages arising at the epithelial phase of implantation form the blueprint for the placenta and thus underpin foetal growth trajectories, pregnancy health and offspring health. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by grants from Wellbeing of Women, Diabetes UK, the NIHR Local Comprehensive Research Network and Manchester Clinical Research Facility, and the Department of Health Scientist Practitioner Training Scheme. None of the authors has any conflict of interest to declare.
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Affiliation(s)
- Peter T Ruane
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK,Correspondence address. Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, School of Medical Sciences, Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9WL, UK. E-mail: https://orcid.org/0000-0002-1476-1666
| | - Terence Garner
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Lydia Parsons
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Phoebe A Babbington
- Department of Reproductive Medicine, Old Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Ivan Wangsaputra
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Susan J Kimber
- Faculty of Biology Medicine and Health, Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, University of Manchester, Manchester, UK
| | - Adam Stevens
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Melissa Westwood
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Daniel R Brison
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK,Department of Reproductive Medicine, Old Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - John D Aplin
- Faculty of Biology, Medicine and Health, Division of Developmental Biology and Medicine, Maternal and Fetal Health Research Centre, School of Medical Sciences, Saint Mary’s Hospital, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK,Maternal and Fetal Health Research Centre, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
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Pisko J, Špirková A, Čikoš Š, Olexiková L, Kovaříková V, Šefčíková Z, Fabian D. Apoptotic cells in mouse blastocysts are eliminated by neighbouring blastomeres. Sci Rep 2021; 11:9228. [PMID: 33927296 PMCID: PMC8085119 DOI: 10.1038/s41598-021-88752-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 04/16/2021] [Indexed: 02/02/2023] Open
Abstract
Apoptosis is a physiological process that occurs commonly during the development of the preimplantation embryo. The present work examines the ability of apoptotic embryonic cells to express a signal promoting their phagocytosis, and quantifies the ability of neighbouring, normal embryonic cells to perform that task. Microscopic analysis of mouse blastocysts revealed phosphatidylserine externalization to be 10 times less common than incidence of apoptotic cells (as detected by TUNEL). In spite of the low frequency of phosphatidylserine-flipping (in inner cell mass, no annexin V staining was recorded), fluorescence staining of the plasma membrane showed more than 20% of apoptotic cells to have been engulfed by neighbouring blastomeres. The mean frequency of apoptotic cells escaping phagocytosis by their extrusion into blastocyst cavities did not exceed 10%. Immunochemically visualised RAC1 (an enzyme important in actin cytoskeleton rearrangement) was seen in phagosome-like structures containing a nucleus with a condensed morphology. Gene transcript analysis showed that the embryonic cells expressed 12 receptors likely involved in phagocytic process (Scarf1, Msr1, Cd36, Itgav, Itgb3, Cd14, Scarb1, Cd44, Stab1, Adgrb1, Cd300lf, Cd93). In conclusion, embryonic cells possess all the necessary mechanisms for recognising, engulfing and digesting apoptotic cells, ensuring the clearance of most dying blastomeres.
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Affiliation(s)
- Jozef Pisko
- Institute of Animal Physiology, Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 040 01, Košice, Slovak Republic
| | - Alexandra Špirková
- Institute of Animal Physiology, Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 040 01, Košice, Slovak Republic
| | - Štefan Čikoš
- Institute of Animal Physiology, Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 040 01, Košice, Slovak Republic
| | - Lucia Olexiková
- Research Institute for Animal Production Nitra, National Agricultural and Food Centre (NPPC), Hlohovecká 2, 951 41, Lužianky, Slovak Republic
| | - Veronika Kovaříková
- Institute of Animal Physiology, Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 040 01, Košice, Slovak Republic
| | - Zuzana Šefčíková
- Institute of Animal Physiology, Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 040 01, Košice, Slovak Republic
| | - Dušan Fabian
- Institute of Animal Physiology, Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 040 01, Košice, Slovak Republic.
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Sihombing MAEM, Safitri M, Zhou T, Wang L, McGinty S, Zhang HJ, Yin Y, Peng Q, Qiu J, Wang G. Unexpected Role of Nonimmune Cells: Amateur Phagocytes. DNA Cell Biol 2021; 40:157-171. [PMID: 33439750 DOI: 10.1089/dna.2020.5647] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Effective and efficient efferocytosis of dead cells and associated cellular debris are critical to tissue homeostasis and healing of injured tissues. This important task was previously thought to be restricted to professional phagocytes (PPs). However, accumulating evidence has revealed another type of phagocyte, the amateur phagocyte (AP), which can also participate in efferocytosis. APs are non-myeloid progenitor/nonimmune cells that include differentiated cells (e.g., epithelial cells, fibroblasts, and endothelial cells [ECs]) and stem cells (e.g., neuronal progenitor cells and mesenchymal cells) and can be found throughout the human body. Studies have shown that APs have two prominent roles: identifying and removing dead cells presumably before PPs reach the site of injury and assisting PPs in the removal of cell corpses and the resolution of inflamed tissue. With respect to the engulfment and degradation of dead cells, APs are slower and less efficient than PPs. However, APs are fundamental to preventing the spread of inflammation over a large area. In this review, we present the diversity and characteristics of healthy and non-neoplastic APs in mammals. We also propose a hypothetical mechanism of the efferocytosis of immunoglobulin G (IgG)-opsonized myelin debris by ECs (APs). Furthermore, the ingestion and clearance of dead cells can induce proinflammatory or anti-inflammatory cytokine production, endothelial activation, and cellular fate transition, which contribute to the progression of disease. An understanding of the role of APs is necessary to develop effective intervention strategies, including potential molecular targets for clinical diagnosis and drug development, for inflammation-related diseases.
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Affiliation(s)
- Maic Audo Eybi Mayer Sihombing
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Maharani Safitri
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Tian Zhou
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Lu Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Sean McGinty
- Division of Biomedical Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Hai-Jun Zhang
- Department of Vascular and Intervention, Tenth People's Hospital of Tongji University, Shanghai, China
| | - Yuxia Yin
- National United Engineering Laboratory for Biomedical Material Modification, Denzhou, China
| | - Qin Peng
- Institute of Systems and Physical Biology, Shenzen Bay Laboratory, Shenzhen, China
| | - Juhui Qiu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, China
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Dean M. Glycogen in the uterus and fallopian tubes is an important source of glucose during early pregnancy†. Biol Reprod 2020; 101:297-305. [PMID: 31201425 DOI: 10.1093/biolre/ioz102] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/16/2019] [Accepted: 06/06/2019] [Indexed: 01/02/2023] Open
Abstract
Pregnancy loss is common during the peri-implantation period in mammals when glucose is required for both embryonic development and decidualization of the endometrium. As the uterus cannot synthesize glucose, all glucose must come directly from maternal circulation as needed or transiently stored as the macromolecule glycogen. Glycogen acts as a glucose reservoir, storing up to 55 000 glucose moieties per molecule. Endometrial glycogen concentrations are correlated with fertility in humans, indicating that glycogen is an essential source of glucose during early pregnancy. In humans and primates, endometrial glycogen concentrations peak during the luteal phase due to progesterone. In contrast, in rats and mink, estradiol triggers an accumulation of uterine glycogen during proestrus and estrus. In mated rats, the glycogen content of the endometrium increases again after implantation due to high levels of glycogen stored in the decidua. In mink, endometrial glycogen reserves are localized in the uterine epithelia at estrus. These reserves are mobilized before implantation, suggesting they are used to support embryonic growth. Uterine glycogen concentrations continue to decrease after implantation in mink, probably due to a lack of decidualization. How ovarian steroids stimulate glycogenesis in the endometrium is unclear, but current evidence suggests that estradiol/progesterone interacts with insulin or insulin-like growth factor signaling. In summary, endometrial glycogen is an essential source of glucose during the peri-implantation period. More work is needed to characterize differences among species, elucidate the fate of the glucose liberated from glycogen, and understand how ovarian steroids regulate glycogen metabolism in the uterus.
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Affiliation(s)
- Matthew Dean
- Department of Animal Science, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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