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.

Focal adhesions disassemble during early pregnancy in rat uterine epithelial cells

2008 ◽  
Vol 20 (8) ◽  
pp. 892 ◽  
Author(s):  
Yui Kaneko ◽  
Laura A. Lindsay ◽  
Christopher R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Cell Surface ◽  
Focal Adhesion ◽  
Basal Cell ◽  
Early Pregnancy ◽  
Focal Adhesions ◽  
Uterine Epithelial Cells ◽  
Focal Adhesion Proteins ◽  
Decidual Cells ◽  
Implantation Sites

During early pregnancy in rodents, invasion of the blastocyst into the endometrial decidual cells is accompanied by the removal of uterine epithelial cells around the implantation sites. The present study investigated the distribution and expression of two focal adhesion proteins, namely talin and paxillin, in rat uterine epithelial cells during early pregnancy and their role in the loss of these cells at the time of implantation. A major distributional change of talin and paxillin was demonstrated in uterine epithelial cells during early pregnancy. From a highly concentrated expression along the basal cell surface on Day 1 of pregnancy, talin and paxillin were lost from the basal cell surface at the time of implantation. There was also a corresponding statistically significant decrease in paxillin seen through western blotting analysis. Together, these observations suggest that uterine epithelial cells are less adherent to the underlying basal lamina due to the disassembly of talin and paxillin from focal adhesions, facilitating removal of these cells at the time of implantation. This phenomenon was restricted to the period of receptivity because talin and paxillin reappeared along the basal cell surface soon after implantation.

310. CAVEOLIN 1 AND 2 IN THE UTERUS DURING EARLY PREGNANCY

2010 ◽  
Vol 22 (9) ◽  
pp. 110
Author(s):  
R. J. Madawala ◽  
C. R. Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Protein Expression ◽  
Early Pregnancy ◽  
Basolateral Membrane ◽  
Membrane Curvature ◽  
Major Protein ◽  
Uterine Epithelial Cells ◽  
Caveolin 1 ◽  
Blastocyst Implantation

Rat uterine epithelial cells undergo many changes during early pregnancy in order to become receptive to blastocyst implantation. These changes include basolateral folding and the presence of vesicles of various sizes which are at their greatest number during the pre-implantation period. The present study investigated the possible role that caveolin 1 and 2 plays in this remodelling specifically days 1, 3, 6, 7, and 9 of pregnancy. Caveolin is a major protein in omega shaped invaginations of the plasma membrane called caveolae that are considered to be specialised plasma membrane subdomains. Caveolae are rich in cholesterol, glycosphingolipids, and GPI anchored proteins and are involved in endocytosis and membrane curvature. Immunofluorescence microscopy has shown caveolin 1 and 2 on day 1 of pregnancy are localised to the cytoplasm of luminal uterine epithelial cells, and by day 6 of pregnancy (the time of implantation), it concentrates basally. By day 9 of pregnancy, expression of both caveolin 1 and 2 in luminal uterine epithelia is cytoplasmic as seen on day 1 of pregnancy. A corresponding increase in protein expression of caveolin 1 on day 6 of pregnancy in luminal uterine epithelia was observed. Interestingly however, caveolin 2 protein expression decreases at the time of implantation as found by western blot analysis. Both caveolin 1 and 2 were localised to blood vessels within the endometrium and myometrium and also the muscle of the myometrium in all days of pregnancy studied. In addition, both caveolin 1 and 2 were absent from glandular epithelium, which is interesting considering that they do not undergo the plasma membrane transformation. The localisation and expression of caveolin 1 and 2 in rat luminal uterine epithelium at the time of implantation suggest possible roles in trafficking of cholesterol and/or various proteins for either degradation or relocation. Caveolins may contribute to the morphology of the basolateral membrane seen on day 6 of pregnancy. All of which may play an important role during successful blastocyst implantation.

445. Focal adhesions disassemble during early pregnancy in rat uterine epithelial cells

2008 ◽  
Vol 20 (9) ◽  
pp. 125
Author(s):  
Y. Kaneko ◽  
L. A. Lindsay ◽  
C. R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Western Blotting ◽  
Early Pregnancy ◽  
Active Form ◽  
Focal Adhesions ◽  
Proteolytic Fragment ◽  
Uterine Epithelial Cells ◽  
Western Blotting Analysis ◽  
Blotting Analysis ◽  
Calpain 2

Successful blastocyst implantation require uterine epithelial cells (UECs) to undergo the 'plasma membrane transformation' followed by the removal of these cells around the implantation sites. The present study investigated the distribution and expression of two principal focal adhesion proteins talin and paxillin in rat UECs during early pregnancy and their role in the loss of these cells at the time of implantation. Results from immunofluorescence microscopy have demonstrated a major distributional change of talin and paxillin in UECs where an intense basal staining of these proteins on day 1 of pregnancy was lost at time of implantation. This was consistent with the significant decrease in paxillin seen through western blotting analysis. Interestingly the amount of talin was not significantly different between day 1 of pregnancy and at the time of implantation with a calpain 2 mediated proteolytic fragment of talin seen on both of these days of pregnancy. Calpain 2 activity was further investigated through western blotting analysis and increases in the active form of calpain 2 at the time of implantation. These observations suggest that talin and paxillin have disassembled from the site of focal adhesions where talin is undergoing cleavage by active calpain 2 at the time of implantation. This allows UECs to become less adherent to the underlying basal lamina facilitating their removal during blastocyst invasion. Hence, disassembly of focal adhesions at the time of implantation is a critical event for successful implantation and placentation.

Claudin 7 is reduced in uterine epithelial cells during early pregnancy in the rat

2012 ◽  
Vol 139 (4) ◽  
pp. 583-593 ◽  
Author(s):  
Connie E. Poon ◽  
Romanthi J. Madawala ◽  
Margot L. Day ◽  
Christopher R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Early Pregnancy ◽  
Uterine Epithelial Cells
Sign in / Sign up

Export Citation Format

Share Document