To investigate the presence of focal adhesion-associated proteins palladin and lasp-1 in the rat uterus during early pregnancy. During this time the luminal epithelial cells undergo controlled focal-adhesion disassembly and research into this process can help to determine which proteins have a key involvement in adhesion disassembly in moving cells.
Luminal uterine epithelial cells were obtained from rats during different stages of early pregnancy. Day 1 of early pregnancy corresponded to when focal adhesions are intact in the luminal uterine epithelial cells and day 6 is characterized by a controlled focal adhesion loss. Luminal epithelial cells were used for western blotting and whole sections of rat uterus were used for immunohistochemistry to determine protein presence and localization.
Focal adhesion-associated proteins lasp-1 and palladin were found to significantly increase after controlled adhesion loss on day 6 of early pregnancy in the rat. Palladin isoform 140 kDa is absent on day 1 of pregnancy, whereas the more ubiquitous 90 kDa isoform is present. On day 6, 140 kDa palladin isoform significantly increases, along with lasp-1. Palladin 90kDa isoform remains at similar levels on day 6.
Previous studies have shown that palladin 140 kDa isoform and lasp-1 co-localize in some cancer types and are potential indicators of metastatic ability of tumour types, with the expression of these proteins being directly proportional to the potential for cell movement to occur. Palladin and lasp-1 have not been researched in the uterus prior to this study.
Determining proteins that are involved in focal adhesion loss during early pregnancy contribute to understandings of how successful blastocyst implantation occurs. Additionally, using adhesion loss in uterine luminal epithelial cells in early pregnancy as a contextually comparative model to adhesion loss in moving cells, such as metastasis, can potentially give rise to biomarkers for malignancy in tumours such as endometrial cancer, which is currently being simultaneously studied alongside this project.