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.

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.

Cholesterol in the plasma membrane of uterine epithelial cells: a freeze-fracture cytochemical study with digitonin

1985 ◽  
Vol 78 (1) ◽  
pp. 163-172
Author(s):  
C.R. Murphy ◽  
B. Martin
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Tight Junctions ◽  
Freeze Fracture ◽  
Cholesterol Content ◽  
Apical Plasma Membrane ◽  
Lesion Formation ◽  
Uterine Epithelial Cells ◽  
Cytochemical Study ◽  
Blastocyst Implantation

Freeze-fracture cytochemistry with digitonin has been used to examine the cholesterol content of the plasma membrane of uterine epithelial cells during the early stages of pregnancy in the rat. Lesions caused by digitonin complexing with cholesterol were seen on both lateral and apical portions of the membrane but tight junctions and desmosomes were lesion-free. Compared with day 1 of pregnancy, lesions on the apical plasma membrane were much more extensive and some were of different morphology on day 6 - the day of blastocyst implantation. We consider mechanisms of lesion formation and interpret the results to indicate a higher content and perhaps a different organization of cholesterol in the apical plasma membrane on day 6 of pregnancy. We also suggest how this increase may occur.

Changes in the fine structure of the apical plasma membrane of endometrial epithelial cells during implantation in the rat

1982 ◽  
Vol 55 (1) ◽  
pp. 1-12
Author(s):  
C.R. Murphy ◽  
J.G. Swift ◽  
T.M. Mukherjee ◽  
A.W. Rogers
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Normal Pregnancy ◽  
Ovariectomized Rats ◽  
Apical Plasma Membrane ◽  
Embryonic Cells ◽  
Blastocyst Implantation ◽  
First Contact ◽  
Endometrial Epithelial Cells

In previous work we have shown that ovarian hormones, when injected into ovariectomized rats, alter the fine structure of the plasma membrane of endometrial epithelial cells. In this paper freeze-fractures have been used to study the apical plasma membrane of endometrial epithelial cells of rats during the period of blastocyst implantation of normal pregnancy. On day 1 of pregnancy there were 2354 +/− 114 intramembranous particles (IMPs) per micrometer2 of membrane. The particles were spherical and randomly distributed. On day 5 of pregnancy IMP density rose to 2899 +/− 289 per micrometer2 and some rod-shaped particles were also visible. By day 6 of pregnancy IMP density had risen to 4014 +/− 206 per micrometer2 and there were more rod-shaped IMPs than before. In addition, on day 6 IMPs were also present as rows of particles and some gap-junction-like arrays of particles were also seen. Our findings indicate that there are fine-structural alterations in the apical plasma membrane of endometrial epithelial cells, the site of first contact between maternal and embryonic cells, during the period of early pregnancy. The findings are discussed in the light of suggested mechanisms of blastocyst attachment to the uterine epithelium at implantation.

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

Prominin-1 glycosylation changes throughout early pregnancy in uterine epithelial cells under the influence of maternal ovarian hormones

2017 ◽  
Vol 29 (6) ◽  
pp. 1194 ◽  
Author(s):  
Samson N. Dowland ◽  
Romanthi J. Madawala ◽  
Connie E. Poon ◽  
Laura A. Lindsay ◽  
Christopher R. Murphy
Keyword(s):  
Epithelial Cells ◽  
Early Pregnancy ◽  
Core Protein ◽  
Apical Plasma Membrane ◽  
Apical Region ◽  
Uterine Epithelial Cells ◽  
Oestrogen Treatment ◽  
Extracellular Loops ◽  
Progesterone Treatment ◽  
Ovariectomised Rats

In preparation for uterine receptivity, the uterine epithelial cells (UECs) exhibit a loss of microvilli and glycocalyx and a restructuring of the actin cytoskeleton. The prominin-1 protein contains large, heavily glycosylated extracellular loops and is usually restricted to apical plasma membrane (APM) protrusions. The present study examined rat UECs during early pregnancy using immunofluorescence, western blotting and deglycosylation analyses. Ovariectomised rats were injected with oestrogen and progesterone to examine how these hormones affect prominin-1. At the time of fertilisation, prominin-1 was located diffusely in the apical domain of UECs and 147- and 120-kDa glycoforms of prominin-1 were identified, along with the 97-kDa core protein. At the time of implantation, prominin-1 concentrates towards the APM and densitometry revealed that the 120-kDa glycoform decreased (P < 0.05), but there was an increase in the 97-kDa core protein (P < 0.05). Progesterone treatment of ovariectomised rats resulted in prominin-1 becoming concentrated towards the APM. The 120-kDa glycoform was increased after oestrogen treatment (P < 0.0001), whereas the 97-kDa core protein was increased after progesterone treatment (P < 0.05). Endoglycosidase H analysis demonstrated that the 120-kDa glycoform is in the endoplasmic reticulum, undergoing protein synthesis. These results indicate that oestrogen stimulates prominin-1 production, whereas progesterone stimulates the deglycosylation and concentration of prominin-1 to the apical region of the UECs. This likely presents the deglycosylated extracellular loops of prominin-1 to the extracellular space, where they may interact with the implanting blastocyst.

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