446. Ezrin and EBP50 relocate apically in rat uterine epithelial cells during contact with opposing cells, except cells contacting the blastocyst

2008 ◽  
Vol 20 (9) ◽  
pp. 126
Author(s):  
L. Venuto ◽  
L. A. Lindsay ◽  
C. R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Protein Complex ◽  
Apical Membrane ◽  
Cell Ultrastructure ◽  
Cell Fractionation ◽  
Uterine Epithelial Cells ◽  
Pregnant Rat ◽  
Signalling Molecules ◽  
Indirect Immunofluorescence Microscopy ◽  
Membrane Transformation

Uterine epithelial cells are important in constantly maintaining a tissue protective barrier, and only under the specific hormonal conditioning of pregnancy which involves a remodelling of the cell ultrastructure termed the 'plasma membrane transformation'. This allows for the successful invasion of the blastocyst. Indirect immunofluorescence microscopy in rat uterine epithelial cells during pregnancy shows that ezrin and EBP50 are relocated to the apical membrane upon lumen closure at the time of implantation, and on average results in 90% colocalisation. Ezrin and EBP50 function as a linked protein complex at the time of implantation seen through immunoprecipitation results from day 6 of pregnancy. The ezrin-EBP50 complex is also associated with the membrane, shown using cell fractionation and western blotting analysis in which ezrin increased dramatically in the membrane concentrated fraction, and correspondingly decreased in the cytosolic fraction leading up to implantation. At the apical membrane these proteins are likely associating with intra-membranous signalling molecules which allow communication between contacting cells. The same protein complex is also relocated to the apical membrane when cells contact an inanimate filament inserted into the uterus of a non-pregnant rat. The only unique contacting circumstance in which these proteins are not seen at the apical membrane is within the implantation chamber itself, more specifically the cells in direct contact with the implanting blastocyst. These results highlight the unique situation that is implantation, which involves specific blastocyst signalling and influence upon the uterine epithelial cells lining the implantation chamber. It may be that the ezrin-EBP50 protein complex is critical at the earlier stage of apposition, and through blastocyst influence, are subsequently lost from the apical membrane to allow for successful invasion.

scholarly journals Uterine Epithelial Cells Undergo a Plasma Membrane Transformation During Early Pregnancy in the Domestic Cat (Felis catus )

2018 ◽  
Vol 301 (9) ◽  
pp. 1497-1505 ◽  
Author(s):  
Jessica S. Dudley ◽  
Christopher R. Murphy ◽  
Michael B. Thompson ◽  
Tanya Carter ◽  
Bronwyn M. McAllan
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Early Pregnancy ◽  
Felis Catus ◽  
Domestic Cat ◽  
Uterine Epithelial Cells ◽  
Membrane Transformation

117. THE ROLE OF FOCAL ADHESION PROTEINS AND THEIR HORMONAL REGULATION IN RAT UTERINE EPITHELIAL CELLS DURING EARLY PREGNANCY

2010 ◽  
Vol 22 (9) ◽  
pp. 35 ◽  
Author(s):  
Y. Kaneko ◽  
M. Day ◽  
C. R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Cell Line ◽  
Focal Adhesion ◽  
Early Pregnancy ◽  
Apical Membrane ◽  
Trophoblast Cells ◽  
Uterine Epithelial Cells ◽  
Integrin Beta1 ◽  
Focal Adhesion Proteins ◽  
Integrin Beta3

Uterine epithelial cells (UECs) undergo extensive alteration during early pregnancy followed by their removal in order for the implanting blastocyst to penetrate into the underlying endometrium. Focal adhesions (FAs) may play a role during this process as FAs provide adhesion between the cell and its underlying basal lamina. The present study investigated the distribution and expression of FA proteins in rat UECs at the time of implantation and their hormonal control as well as their expression in blastocyst stage embryos. Immunofluorescence microscopy showed that the principal focal adhesion proteins, talin and paxillin, were localised along the basal cell surface of UECs on day 1 of pregnancy, however they were markedly reduced from the site of FAs at the time of implantation. This is thought to be a critical process in the removal of UECs, which allows the invasion of the blastocyst into the underlying endometrium. Hormone treatments in ovariectomised rats showed that disassembly of talin and paxillin from the site of FAs were predominantly under the control of progesterone. Formation of FAs is initiated by the clustering of specific integrin subunits and both integrin beta1 and beta3 colocalised and interacted with talin at the site of FAs on day 1 of pregnancy. Integrin beta1 and beta3 disassembled from the site of FAs at the time of implantation, however integrin beta3 significantly increased along the apical membrane at this time suggesting a role in embryo attachment. In the rat blastocyst, integrin beta3 was concentrated around the nuclei of the trophoblast cells and once the blastocyst was placed onto a receptive endometrial cell line, Ishikawa cell line, integrin beta3 relocated to the apical membrane of the trophoblast cells. Taken together, our results show that disassembly of FA proteins plays a pivotal role in the removal of UECs in order to establish successful implantation and is tightly regulated by ovarian hormones.

THE PLASMA MEMBRANE TRANSFORMATION: A KEY CONCEPT IN UTERINE RECEPTIVITY

2001 ◽  
Vol 9 (3) ◽  
pp. 197-208 ◽  
Author(s):  
CR Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Early Pregnancy ◽  
Fetal Tissue ◽  
Human Beings ◽  
Human Uterus ◽  
Uterine Receptivity ◽  
Uterine Epithelial Cells ◽  
Considerable Body ◽  
Membrane Transformation

The first site of contact between maternal and fetal tissue at the beginning of blastocyst attachment and implantation is the plasma membrane of uterine epithelial cells. Indeed, as has been noted often, regardless of the mode of placentation which ultimately occurs, contact between this plasma membrane and that of the trophoblast is a common beginning to implantation in most species studied so far, which now range from viviparous lizards to human beings. The similarities in these early events of uterine receptivity and placentation go further than mere contact between opposing surfaces however. A considerable body of evidence indicates that the behaviour of the plasma membrane of uterine epithelial cells during early pregnancy has many common aspects across species including humans. This review pays special attention to events in the human uterus and the epithelial cells in particular, but examines them within the wider context of uterine receptivity for implantation across species.

Sign in / Sign up

Export Citation Format

Share Document