The endometrial cell surface and implantation. Expression of the polymorphic mucin MUC-1 and adhesion molecules during the endometrial cycle.
The cell surface mucin MUC-1 is present in endometrial epithelial cells and their associated apical glycocalyx and is also released into gland lumens as a secretory product. MUC-1 mRNA and core protein are found at low levels in the proliferative phase of the cycle, but their abundance increases after ovulation. Endometrial MUC-1 has been found to carry sialokeratan sulphate chains and these show a dramatically increased abundance in cells and secretions in the post-ovulatory phase of the cycle, reaching a maximum in secretions 6-7 days after the LH peak. The apical epithelium also contains adhesion receptor molecules of the integrin and CD44 families. MUC-1 is large and highly glycosylated and probably extends farther from the cell surface than these 'conventional' glycoprotein receptors. It has the potential to inhibit sterically receptor-mediated cell-cell adhesion. However, it is also possible that MUC-1 displays specific (e.g., glycan) recognition structures for the initial attachment of the blastocyst or that the embryo may create a specialised microenvironment in which to implant.
Aplin
J D
JD
Department of Obstetrics and Gynaecology, University of Manchester, U.K.
Seif
M W
MW
Graham
R A
RA
Hey
N A
NA
Behzad
F
F
Campbell
S
S
D015815:Cell Adhesion Molecules / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology*; D010064:Embryo Implantation / Q000502:physiology*; D004622:Embryo, Mammalian / Q000502:physiology; D004717:Endometrium / Q000502:physiology* / Q000648:ultrastructure*; D004848:Epithelium / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D006031:Glycosylation; D006801:Humans; D008562:Membrane Glycoproteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D018396:Mucin-1; D009077:Mucins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011247:Pregnancy
D015815:Cell Adhesion Molecules; D008562:Membrane Glycoproteins; D018396:Mucin-1; D009077:Mucins