Alterations in tight junction molecules of uterine epithelial cells during early pregnancy in the rat

2002 ◽  
Vol 104 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Megan D. Orchard ◽  
Christopher R. Murphy
2010 ◽  
Vol 22 (9) ◽  
pp. 110
Author(s):  
R. J. Madawala ◽  
C. R. Murphy

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Takashi Kojima ◽  
Mitsuru Go ◽  
Ken-ichi Takano ◽  
Makoto Kurose ◽  
Tsuyoshi Ohkuni ◽  
...  

The mucosal barrier of the upper respiratory tract including the nasal cavity, which is the first site of exposure to inhaled antigens, plays an important role in host defense in terms of innate immunity and is regulated in large part by tight junctions of epithelial cells. Tight junction molecules are expressed in both M cells and dendritic cells as well as epithelial cells of upper airway. Various antigens are sampled, transported, and released to lymphocytes through the cells in nasal mucosa while they maintain the integrity of the barrier. Expression of tight junction molecules and the barrier function in normal human nasal epithelial cells (HNECs) are affected by various stimuli including growth factor, TLR ligand, and cytokine. In addition, epithelial-derived thymic stromal lymphopoietin (TSLP), which is a master switch for allergic inflammatory diseases including allergic rhinitis, enhances the barrier function together with an increase of tight junction molecules in HNECs. Furthermore, respiratory syncytial virus infection in HNECsin vitroinduces expression of tight junction molecules and the barrier function together with proinflammatory cytokine release. This paper summarizes the recent progress in our understanding of the regulation of tight junctions in the upper airway epithelium under normal, allergic, and RSV-infected conditions.


2008 ◽  
Vol 20 (9) ◽  
pp. 125
Author(s):  
Y. Kaneko ◽  
L. A. Lindsay ◽  
C. R. Murphy

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.


2012 ◽  
Vol 139 (4) ◽  
pp. 583-593 ◽  
Author(s):  
Connie E. Poon ◽  
Romanthi J. Madawala ◽  
Margot L. Day ◽  
Christopher R. Murphy

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