Junctional plaque proteins shift to the apical surface of uterine epithelial cells during early pregnancy in the rat

1999 ◽  
Vol 101 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Megan D. Orchard ◽  
Timothy J. Shaw ◽  
Christopher R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Early Pregnancy ◽  
Apical Surface ◽  
Uterine Epithelial Cells

312. THE DISTRIBUTION OF PROMININ-1 IN THE RAT UTERUS DURING EARLY PREGNANCY

2010 ◽  
Vol 22 (9) ◽  
pp. 112
Author(s):  
S. N. Dowland ◽  
L. A. Lindsay ◽  
C. R. Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Early Pregnancy ◽  
Cell Types ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Uterine Epithelial Cells ◽  
Uterine Epithelial Cell ◽  
Terminal Web ◽  
Blastocyst Implantation

Prominin-1 is a recently discovered pentaspan membrane protein present in characteristic cholesterol-based vesicles and associated with microvilli. These vesicles are used to deliver prominin-1 to the apical plasma membrane in a number of cell types. Previous work on uterine epithelial cells has demonstrated a loss of microvilli and the presence of large, cholesterol-based vesicles at the time of implantation. Thus this study aims to determine a role for prominin-1 in rat uterine epithelial cells during early pregnancy. Immunofluorescence microscopy reveals punctate and diffuse prominin-1 staining below the apical plasma membrane on day 1 of pregnancy. At the time of blastocyst implantation (day 6) however, prominin-1 appears concentrated at the apical surface of the cell. Western blotting of isolated uterine epithelial cell lysate revealed a change in prominin-1 glycosylation during early pregnancy. Prominin-1 was determined to be glycosylated on day 1 of pregnancy, but these carbohydrate side chains were lost by the time of attachment. Results seen in the present study indicate that prominin-containing vesicles may be prevented from reaching the apical plasma membrane by the terminal web on day 1 of pregnancy. On day 6, the loss of the terminal web may allow the vesicles to approach and incorporate into the apical plasma membrane, as seen with other uterine vesicles. The deglycosylation of prominin-1 at this time is suggested to allow the protein to bind its ligand and activate downstream signalling pathways that permit implantation. This study constitutes the first reported observation of prominin in endometrial lumenal epithelial cells. These preliminary results, in consideration with previous reports of prominin expression in trophoblast cells, suggest an important role for this protein in early pregnancy.

scholarly journals Membrane trafficking directed by VAMP2 and syntaxin 3 in uterine epithelial cells

Reproduction ◽  
2020 ◽  
Vol 160 (4) ◽  
pp. 533-546
Author(s):  
Sadaf N Kalam ◽  
Louise Cole ◽  
Laura Lindsay ◽  
Christopher R Murphy
Keyword(s):  
Epithelial Cells ◽  
Early Pregnancy ◽  
Membrane Trafficking ◽  
Snare Proteins ◽  
Apical Surface ◽  
Uterine Receptivity ◽  
Uterine Epithelial Cells ◽  
Syntaxin 3 ◽  
Cytoskeletal Disruption

Luminal uterine epithelial cells (UEC) have a surge in vesicular activity during early uterine receptivity. It has been predicted these vesicles exit the UEC via exocytosis resulting in secretion and membrane trafficking. The present study investigated the changes in SNARE proteins VAMP2 (v-SNARE) and syntaxin 3 (t-SNARE) localisation and abundance in UECs during early pregnancy in the rat. We found VAMP2 and syntaxin 3 are significantly higher on day 5.5 compared to day 1 of pregnancy. On day 5.5, VAMP2 is perinuclear and syntaxin 3 is concentrated in the apical cytoplasm compared to a cytoplasmic localisation on day 1. This change in localisation and abundance show VAMP2 and syntaxin 3 are involved in vesicular movement and membrane trafficking in UECs during early pregnancy. This study also investigated the influence of cytoskeletal disruption of microtubules and actin filaments on VAMP2 and syntaxin 3 in UECs grown in vitro, since microtubules and actin influence vesicle trafficking. As expected, this study found disruption to microtubules with colchicine and actin with cytochalasin D impacted VAMP2 and syntaxin 3 localisation. These results suggest VAMP2 and syntaxin 3 are involved in the timely trafficking of vesicular membranes to the apical surface in UECs during early pregnancy, as are of microtubules and actin.

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.

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