Ezrin and EBP50 redistribute apically in rat uterine epithelial cells at the time of implantation and in response to cell contact.
Uterine epithelial cells (UECs) undergo extensive morphological remodelling in preparation for an implanting blastocyst. This remodelling involves changes in the actin cytoskeleton and surface structures including microvilli. Ezrin and ezrin-radixin-moesin-binding protein-50-kDa (EBP50) link actin filaments to intra-membranous adhesion molecules and are important molecules in polarised epithelia. The current study is the first to describe the colocalisation and molecular association of ezrin and EBP50 in rat UECs by using immunofluorescence microscopy and immunoprecipitation techniques. These proteins have also been localised in relation to uterine epithelial cytoskeletal rearrangement during early pregnancy in the rat and to the effect of apical surface contact between opposing epithelial cells, blastocyst contact and contact with a silicon filament. Immunofluorescence microscopy has revealed that ezrin and EBP50 respond to contact between opposing epithelial cells and increase apically on day 6 of pregnancy. This apical distribution is also observed in UECs in contact with a silicon filament. Ezrin and EBP50 are however absent within the implantation chamber itself, seemingly mimicking the events that take place in leucocyte-endothelium binding. Thus, ezrin and EBP50 occur apically in UECs at the time of implantation in the rat and in response to a substitute blastocyst (filament) suggesting a role for these proteins in the cytoskeletal rearrangements that facilitate uterine receptivity and blastocyst-epithelial adhesion. Their loss within the implantation chamber possibly allows the subsequent invasion of the embryo.
Cell and Reproductive Biology Laboratory, School of Medical Sciences, Anderson Stuart Building F13, Sydney, NSW, 2006, Australia. lvenuto@anatomy.usyd.edu.au
Laura
L
Lecce
Laura A
LA
Lindsay
Christopher R
CR
Murphy
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D010064:Embryo Implantation / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D010750:Phosphoproteins / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D017923:Sodium-Hydrogen Exchangers; D014599:Uterus / Q000166:cytology / Q000378:metabolism*; D000099149:Ezrin
D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D010750:Phosphoproteins; D017923:Sodium-Hydrogen Exchangers; D000099149:Ezrin; C093376:sodium-hydrogen exchanger regulatory factor