scholarly journals Expression of Adrenomedullin, a Hypotensive Peptide, in the Trophoblast Giant Cells at the Embryo Implantation Site in Mouse

1998 ◽  
Vol 203 (2) ◽  
pp. 264-275 ◽  
Author(s):  
Shinichi Yotsumoto ◽  
Tokihiko Shimada ◽  
Chang-Yi Cui ◽  
Hiroshi Nakashima ◽  
Hiroyuki Fujiwara ◽  
...  
Keyword(s):  
Embryo Implantation ◽  
Giant Cells ◽  
Implantation Site ◽  
Trophoblast Giant Cells

scholarly journals Immunohistochemical Examination of Trophoblast Syncytialization during Early Placentation in Sheep

2019 ◽  
Vol 20 (18) ◽  
pp. 4530 ◽  
Author(s):  
Heewon Seo ◽  
Fuller W. Bazer ◽  
Robert C. Burghardt ◽  
Greg A. Johnson
Keyword(s):  
Molecular Markers ◽  
Caspase 3 ◽  
Embryo Implantation ◽  
Giant Cells ◽  
Immunohistochemical Localization ◽  
Tunel Staining ◽  
Rapid Enlargement ◽  
Lateral Fusion ◽  
Trophoblast Giant Cells ◽  
Laser Capture

During the peri-implantation period, multinucleated syncytia are formed in the sheep placenta. For over 20 years the scientific consensus has been that during trophoblast syncytialization in sheep, binucleate trophoblast giant cells (BNCs) differentiate from mononuclear trophoblast cells, and individual BNCs fuse with individual luminal epithelial (LE) cells to form trinucleate cells. These trophoblast–LE syncytial plaques then grow through continued BNC migration and fusion. Therefore, LE cells are thought to be incorporated into syncytial plaques. However, these ideas were based on electron microscopy studies, without benefit of molecular markers for BNC and LE cells to support conclusions. The aim of this study was to observe interactions between BNCs and uterine LE cells using immunohistochemical localization for molecular markers for BNCs and uterine LE cells. We performed immunofluorescence staining, laser capture microdissection, and TUNEL staining on the uterine–placental tissues of sheep during early placentation. We observed: (1) syncytial cells containing more than two nuclei within the trophoblast cell layer; (2) depolarized LE cells that express caspase 3 and stain positively for TUNEL; (3) engulfment of caspase 3-positive LE cells by trophoblast giant cells (TGCs) and empty spaces within the LE layer at sites of implantation; (4) rapid enlargement of syncytial plaques; and (5) E-cadherin and TUNEL-positive cells within the uterine stroma underlying degenerating LE was coincident with accumulation of CD45-positive cells at these sites. These data suggest that during early placentation: (1) fusion between trophoblasts is not limited to the formation of BNCs, and the term ‘trophoblast giant cell (TGC)’ may be appropriate; (2) LE cells undergo apoptosis; (3) apoptotic LE cells are eliminated by TGCs; (4) fusion is not limited to the incorporation of new BNCs but involves the lateral fusion between growing syncytial plaques; and (5) TGCs carry apoptotic LE cells away from the uterine–placental interface for elimination by immune cells within the stroma. These data indicate that uterine LE cells are not incorporated into syncytial plaques, but are engulfed and eliminated, and that early placentation in sheep is more similar to early placentation in humans than is currently understood in that both develop mononucleated cytotrophoblast and multinucleated syncytiotrophoblast layers of entirely placental origin. The elimination of LE cells by sheep TGCs might provide insights into elimination and penetration of LE cells during human embryo implantation.

1.  Heme Oxygenase‐1 Enzyme Deficiency Affects Uterine Natural Killer Cell Function During Murine Pregnancy 

2017 ◽  
Author(s):  
Tracy Zhang
Keyword(s):  
Natural Killer ◽  
Heme Oxygenase ◽  
Cell Function ◽  
Recurrent Miscarriage ◽  
Embryo Implantation ◽  
Killer Cell ◽  
Implantation Site ◽  
Heme Oxygenase 1 ◽  
Unk Cells ◽  
Uterine Natural Killer

Recurrent miscarriage is a condition that affects 1% of all women, and rejection of the fetus by the mother's immune system is thought to be one of the underlying causes. The mechanisms of maternal tolerance vital to a successful pregnancy are not well understood; however, uterine natural killer (uNK) cells are implicated as they comprise over 70% of immune cells in the uterus during early pregnancy. Heme oxygenase‐1 (HO‐1) is an enzyme that is known to be immunosuppressive. Moreover, mice missing HO‐1 have extremely high abortion rates. This study is the first to analyze the effects of HO‐1 deficiency specifically on uNK cells. We posit that an absence of HO‐1 affects normal uNK cell‐mediated immunosuppression, and also possibly their ability to modify uterine spiral arteries supplying blood to the fetus. Our study analyzed embryos from mice lacking or deficient in HO‐1 on days 8, 10, and 12 of pregnancy. Both number of uNK cells and degree of vascularization were analyzed using immunohistochemistry staining. We observed a significantly higher number of uNK cells in one area of the embryo implantation site and a significantly lower number of cells in another, suggesting the uNK cells are failing to localize properly. Analysis of vascularization is currently ongoing. Since women with multiple miscarriages have been shown to down‐regulate HO‐1, confirmation that absence of HO‐1 leads to implantation site abnormalities could pave the way for future clinical treatments.  

The mechanism of mouse egg-cylinder morphogenesis in vitro

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 277-287
Author(s):  
A. J. Copp
Keyword(s):  
Giant Cell ◽  
Cell Formation ◽  
Cell Movement ◽  
Giant Cells ◽  
Cell Number ◽  
Dependent Change ◽  
Morphogenesis In Vitro ◽  
Trophoblast Giant Cells

The number of trophoblast giant cells in outgrowths of mouse blastocysts was determined before, during and after egg-cylinder formation in vitro. Giant-cell numbers rose initially but reached a plateau 12 h before the egg cylinder appeared. A secondary increase began 24 h after egg-cylinder formation. Blastocysts whose mural trophectoderm cells were removed before or shortly after attachment in vitro formed egg cylinders at the same time as intact blastocysts but their trophoblast outgrowths contained fewer giant cells at this time. The results support the idea that egg-cylinder formation in vitro is accompanied by a redirection of the polar to mural trophectoderm cell movement which characterizes blastocysts before implantation. The resumption of giant-cell number increase in trophoblast outgrowths after egg-cylinder formation may correspond to secondary giant-cell formation in vivo. It is suggested that a time-dependent change in the strength of trophoblast cell adhesion to the substratum occurs after blastocyst attachment in vitro which restricts the further entry of polar cells into the outgrowth and therefore results in egg-cylinder formation.

Replication Timing Predicts Underreplicated Domains in Polyploid Trophoblast Giant Cells

Placenta ◽  
2013 ◽  
Vol 34 (9) ◽  
pp. A8
Author(s):  
Roberta Hannibal ◽  
Edward Chuong ◽  
Juan Carlos Rivera Mulia ◽  
David Gilbert ◽  
Anton Valouev ◽  
...  
Keyword(s):  
Replication Timing ◽  
Giant Cells ◽  
Trophoblast Giant Cells

Parp-1deficiency in ES cells promotes invasive and metastatic lesions accompanying induction of trophoblast giant cells during tumorigenesis in uterine environment

2013 ◽  
Vol 63 (8) ◽  
pp. 408-414 ◽  
Author(s):  
Tadashige Nozaki ◽  
Hiroaki Fujimori ◽  
Junhui Wang ◽  
Hiroshi Suzuki ◽  
Hiroshi Imai ◽  
...  
Keyword(s):  
Es Cells ◽  
Giant Cells ◽  
Metastatic Lesions ◽  
Uterine Environment ◽  
Trophoblast Giant Cells

scholarly journals Characterisation of Osteopontin in an In Vitro Model of Embryo Implantation

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 432 ◽  
Author(s):  
Stéphane C Berneau ◽  
Peter T Ruane ◽  
Daniel R Brison ◽  
Susan J Kimber ◽  
Melissa Westwood ◽  
...  
Keyword(s):  
Secretory Pathway ◽  
Embryo Implantation ◽  
Giant Cells ◽  
Ishikawa Cell ◽  
Altered Expression ◽  
Ishikawa Cells ◽  
Cell Layers ◽  
Endometrial Epithelium ◽  
Vitro Model

At the onset of pregnancy, embryo implantation is initiated by interactions between the endometrial epithelium and the outer trophectoderm cells of the blastocyst. Osteopontin (OPN) is expressed in the endometrium and is implicated in attachment and signalling roles at the embryo–epithelium interface. We have characterised OPN in the human endometrial epithelial Ishikawa cell line using three different monoclonal antibodies, revealing at least nine distinct molecular weight forms and a novel secretory pathway localisation in the apical domain induced by cell organisation into a confluent epithelial layer. Mouse blastocysts co-cultured with Ishikawa cell layers served to model embryo apposition, attachment and initial invasion at implantation. Exogenous OPN attenuated initial, weak embryo attachment to Ishikawa cells but did not affect the attainment of stable attachment. Notably, exogenous OPN inhibited embryonic invasion of the underlying cell layer, and this corresponded with altered expression of transcription factors associated with differentiation from trophectoderm (Gata2) to invasive trophoblast giant cells (Hand1). These data demonstrate the complexity of endometrial OPN forms and suggest that OPN regulates embryonic invasion at implantation by signalling to the trophectoderm.

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