Desmosomes in uterine epithelial cells decrease at the time of implantation: An ultrastructural and morphometric study

Abstract

Displacement of uterine epithelial cells is an important aspect of implantation in the rat and other species, allowing invasion of the blastocyst into the endometrial stroma. Desmosomes, which are part of the lateral junctional complex, function in cell-to-cell adhesion, and are therefore likely to be involved in displacement of uterine epithelial cells at the time of implantation. This study used transmission electron microscopy to study rat uterine epithelial cells during the peri-implantation period to investigate the change in the number of structural desmosomes along the lateral plasma membrane of uterine epithelial cells. We found a significant decrease in the number of desmosomes along the entire lateral plasma membrane as pregnancy progressed. Furthermore, there were also significant decreases in the number of desmosomes on the apical portion of the lateral plasma membrane between all days of pregnancy examined. In addition, on day 6 of pregnancy, the time of attachment, desmosomes were larger and seen as "giant desmosomes." For the first time, this study has shown that there is a significant reduction in cell height and actual number of ultrastructurally observable desmosomes at the time of implantation in the rat. It is proposed that this reduction in desmosome number leads to a decrease in lateral adhesion between uterine epithelial cells at the time of implantation, and hence is involved in the loss of uterine epithelial cells to facilitate blastocyst invasion.

COUP-TFII Mediates Progesterone Regulation of Uterine Implantation by Controlling ER Activity

“…The high expression of these enzymes might account for hyperglycosylation of the apical surface of the mutant uterine luminal epithelium. Another important parameter for uterine epithelial maturation is the presence of desmosomes [36,42,43], adherent junctions of the lateral plasma membrane. Desmosomes are normally lost before implantation to facilitate embryo invasion into the uterine stroma.…”

Real-Time Sensing of Enteropathogenic E. coli-Induced Effects on Epithelial Host Cell Height, Cell-Substrate Interactions, and Endocytic Processes by Infrared Surface Plasmon Spectroscopy

“…Indeed, we found that EspF potentially contributes to cell monolayer height (Figure 2B ). This finding is interesting in light of previous studies linking EspF with intermediate filaments [44] and the involvement of these intermediate filaments in mediating inter-epithelial cell adhesion, epithelial cell architecture [45–47], and possibly height [48]. Although this hypothesis has yet to be further investigated, the results imply that the IR-SPR set-up can be used as a platform for performing a deletion screen and complementation analyses to identify EPEC protein effectors that play a role in decreasing the host cell refractive index and height.…”

Redistribution of adhering junctions in human endometrial epithelial cells during the implantation window of the menstrual cycle

“…From days 1 to 5 of pregnancy, Dp 1/2 mRNA and protein levels decreased and a loss of desmosomes was observed by electron microscopy. A loss of desmosomes during early pregnancy was also found in rat uterine epithelial cells (Preston et al 2004(Preston et al , 2006 by immunostaining against Dsgs and ultrastructural analyses. In addition, Preston et al (2004) observed a different distribution of Dsgs at various stages of pregnancy.…”